Apexification is a method of

dental treatment Dental surgery is any of a number of medical procedures that involve artificially modifying dentition; in other words, surgery of the teeth, gums and jaw bones. Types Some of the more common are: * Endodontic (surgery involving the pulp or r ...

to induce a calcific barrier in a

root In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the sur ...

with incomplete formation or open apex of a tooth with necrotic

pulp Pulp may refer to: * Pulp (fruit), the inner flesh of fruit Engineering * Dissolving pulp, highly purified cellulose used in fibre and film manufacture * Pulp (paper), the fibrous material used to make paper * Molded pulp, a packaging material ...

. Pulpal involvement usually occurs as a consequence of trauma or

caries Tooth decay, also known as cavities or caries, is the breakdown of teeth due to acids produced by bacteria. The cavities may be a number of different colors from yellow to black. Symptoms may include pain and difficulty with eating. Complicatio ...

involvement of young or immature permanent teeth. As a sequelae of untreated pulp involvement, loss of pulp vitality or necrotic pulp took place for the involved teeth. The main purpose of apexification includes restoring the original physiologic structures and functions of the pulp-

dentin Dentin () (American English) or dentine ( or ) (British English) ( la, substantia eburnea) is a calcified tissue of the body and, along with enamel, cementum, and pulp, is one of the four major components of teeth. It is usually covered by e ...

complex of the teeth. In addition to that, the elimination of the pulp tissue within a tooth, the disinfection of root canal system by using irrigants such as

sodium hypochlorite Sodium hypochlorite (commonly known in a dilute solution as bleach) is an inorganic chemical compound with the formula NaOCl (or NaClO), comprising a sodium cation () and a hypochlorite anion (or ). It may also be viewed as the sodium salt of ...

and

ethylenediaminetetraacetic acid Ethylenediaminetetraacetic acid (EDTA) is an aminopolycarboxylic acid with the formula H2N(CH2CO2H)2sub>2. This white, water-soluble solid is widely used to bind to iron (Fe2+/Fe3+) and calcium ions (Ca2+), forming water-soluble complexes ev ...

are the necessary steps to ensure that the purpose of apexification is being met. The apexification procedure will normally requires several monthly appointments or follow-ups to observe any calcific changes induced at the apex of tooth concerned. In these visits, a material known as

calcium hydroxide Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca( OH)2. It is a colorless crystal or white powder and is produced when quicklime ( calcium oxide) is mixed or slaked with water. It has m ...

( Ca(OH)₂ ) will be placed inside the

root canal A root canal is the naturally occurring anatomic space within the root of a tooth. It consists of the pulp chamber (within the coronal part of the tooth), the main canal(s), and more intricate anatomical branches that may connect the root ...

systems to eliminate intracanal

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable d ...

, stimulates

calcification Calcification is the accumulation of calcium salts in a body tissue. It normally occurs in the formation of bone, but calcium can be deposited abnormally in soft tissue,Miller, J. D. Cardiovascular calcification: Orbicular origins. ''Nature M ...

and achieves apical barrier seal at the apex of tooth root. The success rate of applying the traditionally used calcium hydroxide to induce calcific barrier is between 74%-100%. Nowadays, a newer material known as

mineral trioxide aggregate Mineral trioxide aggregate (MTA) was developed for use as a dental root repair material by Mahmoud Torabinejad. It is formulated from commercial Portland cement, combined with bismuth oxide powder for radio-opacity. MTA is used for creating apical ...

(MTA) is widely used as well. Some difficulties are said to be a major clinical challenge when carrying out apexification, including difficulty in achieving appropriate apical seal with an open apex. Besides that, the termination of development of dentinal walls after pulpal pathologies occur will result in roots with thin dentinal wall and thus, producing a higher risk of tooth fracture.

Indication and objectives

Apexification is indicated for immature permanent teeth that are non-vital with incompletely formed roots. The objective of this procedure is to induce root end closure (apexification) at the apices of immature roots through the formation of mineralized tissue. Apical closure can take various forms but in most cases, it appears to be irregular and aberrant. Along with apical closure, root development may or may not continue.

Materials

There are different materials to be used in apexification such as Mineral trioxide aggregate (MTA), Bioceramics and Biodentine.

Mineral trioxide aggregate

Mineral trioxide aggregate Mineral trioxide aggregate (MTA) was developed for use as a dental root repair material by Mahmoud Torabinejad. It is formulated from commercial Portland cement, combined with bismuth oxide powder for radio-opacity. MTA is used for creating apical ...

(MTA) is composed primarily of

tricalcium silicate Alite is an impure form of tricalcium silicate, , sometimes formulated as ( in cement chemist notation), typically with 3-4% of substituent oxides. It is the major, and characteristic, phase in Portland cement. The name was given by Törnebohm i ...

tricalcium aluminate Tricalcium aluminate Ca3Al2O6, often formulated as 3CaO·Al2O3 to highlight the proportions of the oxides from which it is made, is the most basic of the calcium aluminates. It does not occur in nature, but is an important mineral phase in Portl ...

, tricalcium oxide, and silicate oxide. It has been used in

endodontics Endodontics (from the Greek roots ''endo-'' "inside" and ''odont-'' "tooth") is the dental specialty concerned with the study and treatment of the dental pulp. Overview Endodontics encompasses the study (practice) of the basic and clinical ...

as a root-end filling material, and sets in the presence of moisture. It presents in either grey or white form, the difference between the two being that white MTA lacks iron. After numerous testing and analysis, MTA showed superior properties from its physical properties and

biocompatibility Biocompatibility is related to the behavior of biomaterials in various contexts. The term refers to the ability of a material to perform with an appropriate host response in a specific situation. The ambiguity of the term reflects the ongoing de ...

. It is shown to have less marginal gap formation, less leakage and better adaptation than other filling materials. Besides, root ends filled with MTA showed good healing with absence of periradicular inflammation over the root-end filling material, as compared to amalgam. The use of MTA as endodontic repair material stimulates bone formation as well as inhibits

bone resorption Bone resorption is resorption of bone tissue, that is, the process by which osteoclasts break down the tissue in bones and release the minerals, resulting in a transfer of calcium from bone tissue to the blood. The osteoclasts are multi-n ...

. Due to its physical properties and biocompatibility, MTA has been used in numerous clinical situations other than as a root-end filling. It is widely used to repair perforations, to close open apices in apexification, as a direct pulp capping material for deep carious tooth, and to cover pulp stumps for apexogenesis. This material possesses great sealing ability, good

antimicrobial An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals ...

activity, great biocompatibility, and enhances dentin biomineralization. However, there is some known drawbacks to the use of MTA such as the potential release of hazardous substances, potential for discoloration, and inconvenience of handling.

Bioceramics

In order to overcome the limitations of MTA, recent advance in dental materials has introduced bioceramics as a new root canal obturation and repair material. Its composition mainly includes zirconium oxide, calcium silicates, calcium phosphate monobasic, calcium hydroxide, filler, and thickening agents. As a pre-mixed form, it is easy to use and is applied in root canal therapy. Biodentin has similar to or better than those of MTA, from biocompatibility, antimicrobial activity, sealing ability and ability to enhance dentin biomineralization. The bonding ability in a high-humidity environment and color stability of biodentine were significantly better than those of MTA.

Biodentine

Biodentine is a tricalcium silicate-based material, as an alternative to permanent dentin. It is biocompatible and is a new bioactive dentin substitute cement, which is composed of powder that consists of

, dicalcium silicate, calcium carbonate,

calcium oxide Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline, crystalline solid at room temperature. The broadly used term "'' lime''" connotes calcium-containing inorganic ...

zirconium oxide Zirconium dioxide (), sometimes known as zirconia (not to be confused with zircon), is a white crystalline oxide of zirconium. Its most naturally occurring form, with a monoclinic crystalline structure, is the mineral baddeleyite. A dopant sta ...

, and

. It allows good marginal sealing, thus preventing marginal leakage as well as protecting the underlying pulp by inducing the formation of

tertiary dentin Tertiary dentin (including reparative dentin or sclerotic dentin) forms as a reaction to stimulation, including caries, wear and fractures. Tertiary dentin is therefore a mechanism for a tooth to ‘heal’, with new material formation protecting th ...

. Unlike other dentin substitutes, biodentine application does not require any conditioning of the dentin surface in providing good sealing property. This is because tag like structures are formed after the penetration of biodentine material into the dentin tubules. Besides, it can also be bonded with different types of adhesives before finishing the final restoration with composite resin. The setting time of biodentine is shorter as compared with that of MTA, In conclusion, this material is clinically indicated for permanent dentin substitute, direct and indirect pulp capping,

pulpotomy Pulpotomy is a minimally invasive procedure performed in children on a primary tooth with extensive caries but without evidence of root pathology. The minimally invasive endodontic techniques of vital pulp therapy (VPT) are based on improved unders ...

, repair of furcation and root perforations, retrograde root-end filling, and apexification.

Procedure

Proper assessment of the tooth is important in determining an accurate diagnosis in order to formulate an appropriate treatment plan. Clinical evaluation of pulpal status includes a comprehensive history and diagnostic tests. Radiographic examination is used to determine the maturity of the developing root. However, immature teeth are commonly associated with young patients and pulp testing in children is complex and subjective to nature. The following steps are included in this procedure: # The affected tooth is isolated using rubber dam # An access opening is made to reach the

pulp chamber The pulp is the connective tissue, nerves, blood vessels, and odontoblasts that comprise the innermost layer of a tooth. The pulp's activity and signalling processes regulate its behaviour. Anatomy The pulp is the neurovascular bundle ce ...

# A file is placed in the root canal and a

radiograph Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeuti ...

is taken to establish the root length. Care should be taken to avoid pushing instruments through the apex # Remnants of the pulp are then removed using barbed broaches and files # The canal is flushed with

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3% ...

to remove debris and is then irrigated with sodium hypochlorite and saline # The material of choice is placed in the canal and an endodontic plugger is used to push the material to the apical end # A cotton pledget is placed and the cavity is sealed with reinforced

zinc oxide Zinc oxide is an inorganic compound with the Chemical formula, formula . It is a white powder that is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceram ...

eugenol Eugenol is an allyl chain-substituted guaiacol, a member of the allylbenzene class of chemical compounds. It is a colorless to pale yellow, aromatic oily liquid extracted from certain essential oils especially from clove, nutmeg, cinnamon, ...

cement Apexification procedure can be completed in one or two appointments depending on the initial clinical sign and symptoms. The procedure may also vary depending on the materials or medication used. Generally, the treatment paste is allowed to remain for six months before the evaluation for an apical closure.

Follow up

If apical closure has not occurred within six months, the root canal is retreated again with the material of choice. Ideally, the tooth should demonstrate continued apical growth and closure or an apical stop. When closure is observed, the canal is filled with a root canal filling material known as

gutta-percha Gutta-percha is a tree of the genus '' Palaquium'' in the family Sapotaceae. The name also refers to the rigid, naturally biologically inert, resilient, electrically nonconductive, thermoplastic latex derived from the tree, particularly fro ...

References

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