BACKGROUND OF THE INVENTION in the modern day scenario, it has become necessary to undertake travel to long distances for the purposes of education, employment and the like. In the pre-industrial era, the travel of people was limited to a territory, such as, a village or a town. However, such a scenario is not possible in the post-industrial era. As a consequence of the travel, and other allied activities associated with day-to-day living, it is observed that, dietary habits, and general life style have undergone a transformation. Further, materials that are used for processing the foodstuffs are also chemicals, and not natural ingredients as used in the pre-industrial era. As a result, it is further observed that, due to consumption of processed food stuffs and, the accelerated pace of living in the modern day scenario, dental hygiene has become of secondary importance. Also, it is further observed that, the consumption of processed foodstuffs is not restricted to adults alone, but also to children.

Structurally, the roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness. Enamel is the outer layer of the exposed tooth. Enamel is almost entirely composed of calcium salts. It is a hard, thin, translucent layer of calcified substance that envelopes and protects the dentin (the main portion of the tooth structure) of the crown of the tooth. In dentistry, crown refers to the anatomical area of teeth, usually covered by enamel. The pulp is the center (core) of a tooth. It contains nerves and blood vessels and helps fight infection in the tooth. The pulp feeds the tooth by sending nutrients into the middle layer of the tooth (dentin). It can also create new, healthy dentin. Pulp is the softest part of the tooth, which lies in its root and extends all of the way to the top part of the tooth (the crown). It is pertinent to note that the tooth that is formed initially in children is termed as 'primary tooth" in dental parlance. In humans, the first set (the "baby," "milk," "primary" or "deciduous" set) normally starts to appear at about six months of age, although some babies are bom with one or more visible teeth, known as neonatal teeth. Normal tooth eruption at about six months is known as teething, and can be painful.

Continual consumption of processed foodstuffs and improper dental hygiene sets the path for "tooth decay". In dental terminology, "tooth decay" describes the dental condition wherein, the tooth under a variety of harsh conditions breaks down leading to the formation of a cavity, It starts with a hole/opening in the enamel.

The most obvious sign of tooth decay is toothache, particularly after hot or cold foods or drinks. However, pain may not be present until decay has reached an advanced stage. Pits or holes may also, be visible in the teeth. Most tooth decay is discovered at an early stage, during a routine check up. A serious complication can be the development of a tooth abscess - the build-up of pus resulting from a bacterial infection of the centre of the tooth. Infection may spread out from the root of the tooth and to the bones supporting the tooth. Plaque and tartar also irritate the gums, and may lead to a gum disease called gingivitis. Tooth decay may be treated conventionally, by several modes of treatment in accordance with the severity of the tooth decay condition, and also, in accordance with the type of tooth, which is being subjected to treatment, namely, whether, the tooth is "primary tooth", or the tooth being treated is, "permanent tooth". In accordance with the severity of the condition and type of tooth, which is being subjected to treatment, modes of stabilizing the generated tooth decay conditions are known in the art. The known methods include, but are not restricted to, brushing and flossing with fluoride toothpaste and/or receiving fluoride treatments may be enough to reverse early decay, before cavities have formed, a filling if a cavity has formed wherein, a filling is a material that plugs the cavity hole, and restores a tooth to its original shape after the dentist has removed the decay. Alternatively, a crown is deployed, if the decay is severe, and the tooth is badly damaged. Further, it is also possible that, there may be a requirement for a root canal treatment if the pulp of the tooth is infected. A root canal removes the diseased pulp of a tooth. Still further, a possibility for tooth extraction also exists, if the root of the tooth is severely damaged. In such a context, a requirement may arise for replacing the tooth with a bridge or an implant.

As it is obvious to a person skilled in the art, "root canal treatment" is a dental procedure that helps in removing the entire internal parts, mainly pulp tissue of the tooth. It also involves the filling of the prepared empty cavity with a suitable biocompatible material.

The above-mentioned procedure is performed and suggested only when the tooth cannot compensate restoring material in a small cavity on the surface. The procedure involves the removal of the nervous elements of the tooth, which have been infected or decayed already due to microbial action or any physical pressures.

The procedure that involves the root canal is also called as, root canal therapy or root canal treatment. This is the only procedure that can help when the entire pulp and its contents are decayed. This procedure of root canal treatment can be performed by a general dentist. However, it is known to a person skilled in the art that the dentist who specializes in field of treatment inclusive of root canal treatment in which the interior of teeth is concerned is an endodontist. Initially, the tooth area is isolated with the help of a rubber dam kit, which is a rubber sheet fitted with the help of clamps or clips around the tooth, which requires treatment to be performed. The process of isolation enables ease of operation for the dentist and prevents the entry of mixing of fluids from the motor and the saliva in the mouth. Then, the dentist prepares a cavity with the help of an aerator, which is done with proper outline and depth into the root, but, this does not eliminate all the contents of the pulp chamber. Then, the root canal files are used to entirely clean the root. These root canal files increase in thickness, when they enter the root and help in removal of the pulp of the tooth. Several proposals in the art are available, which describe the structure of the rotary files that are deployed in root canal treatment.

A proposal in the art, for instance, Pub. No.: WO/2007/143697 reveals, an endodontic file comprising an elongated, flexible metal, the file having a working portion for cutting or abrading biological material, the working portion comprising a proximal portion and a distal portion, the proximal and distal portions having different cross-sectional flute or core patterns and associated cutting edges. Yet another proposal in the art, for instance, Pub. No.: WO/2003/063724 reveals, an endodontic instrument for root canal treatment, provided having a working portion manipulated by a handle and a connection assembly for attachment with an electronic apex locator. The connection assembly allows the electronic apex locator to be connected to the instrument at or through the coronal end of the handle. Preferably, the connection assembly includes a male/female assembly located within or on the surface the file handle.

Still further, a proposal in the art, United States Patent: 7,435,086 reveals, a dental reamer/file which is in the form of an elongated shank. Still further, a proposal in the art, United States Patent: 7,338,284 reveals an endodontic file, provided for shaping and/or preparing a root canal. The file may include multiple cutting segments separated by non-cutting segments. The cutting segments are tapered and may have a cutting edge formed by plural helical flutes. Further still, a proposal in the art, United States Patent: 6,575,747 reveals a dental instrument, provided for use in an endodontic procedure, which has a file extending from a handle configured to enable the working length of the handle to be varied.

Further still, a proposal in the art, United States Patent No.: 7,198,486 reveals an endodontic file including a discontinuity formed within the file shank. The discontinuity creates a safe breakage point at which the file will fail prior to a failure occurring at any other point along the length of the file. Yet another proposal in the art, United States Patent Application: 20070207438 reveals a rotatable endodontic file for cleaning/shaping a tooth root canal.

A further proposal in the art, United States Patent Application: 20060068362, reveals an endodontic instrument which includes an elongated shaft having a tip and a portion capable of being inserted into the root canal of a tooth.

A further proposal in the art, EP1829497 reveals a dental instrument for endodontic applications.

However, in pediatric dentistry, managing a child patient and concurrently performing intricate dental treatment is a challenge to the practicing dentist. Dentistry in general, has more complicated procedures even without the pediatric patient being involved. These complicated surgical procedures are difficult to handle, especially, when the patient is a child, without specific instruments to overcome these difficulties. The percentage of root canal procedure performed in permanent and primary teeth is presently identified to be equal. The rotary file, which is available to perform root canal treatment in permanent teeth, unfortunately does not fulfill the requirements for primary teeth. The incidence of root canal therapy performed in primary teeth has increased in recent days. This drastic increase is due to modified dietary habits and improper brushing technique followed by parents and children. The importance of root canal therapy in primary teeth has gained attention due to the increased awareness of premature loss of deciduous teeth and its complications.

A rotary dental file is an instrument to perform endodontic procedures in human teeth. The goal of the procedure is to remove dead, decayed material and shape the root canal prior to filling the prepared canal. Examples of instruments of this kind are also referred to in U.S. pat.

No 4,934,934, entitled "Dental file/Reamer instrument, issue on Jun. 19, 1990, to Arpaio Jr, et al. In order to use such an instrument, the rotary files are inserted into a dental drilling instrument. The drilling instrument with the inserted file is manipulated by a dentist to perform root canal therapy. In operation, the endodontic drill is operated at a speed of 250 - 350 revolutions per minute (rpm). The rotary file which is inserted into a drilling instrument should have specific dimensions that would fit any primary teeth. The diameter at the tip for a rotary file plays a role in the enlargement of the canal at the apex. The taper along the working area of the rotary file aids in the enlargement of root canal space. The one - millimeter safe end - cutting tip prevents apical perforation of the root canal space. The working area of the rotary file adapts to the root canal space, cuts, abrades and shapes the root canal of the tooth undergoing endodontic treatment. The working area should be controlled to a specific length, which suits the total length of the primary tooth, alternatively termed "milk teeth". The root canals of primary teeth are narrow and tortuous structures. The rotary files, that are used to shape and rectify these curvatures of the narrow root canal structures in primary teeth, and maintain uniform taper throughout the canal space, have to possess a predefined shape, in accordance with the specific requirement(s) of the delicate root canal structure of the primary tooth of the child patient.

The rotary file, which is deployed for performing dental surgery for permanent teeth of adult patients, is operated in a relatively low speed and accompanied by a corresponding high torque. The high torque creates a risk by making the rotary file to separate at its working area. This is especially true for endodontic files made of Nickel Titanium. File breakage occurs usually about two millimeters from the tip of the file. Separated file tip is quite difficult to extirpate from the root canal space. Sometimes, the file tip is left in patients tooth.

The basic tooth structure for primary tooth and permanent tooth has distinct differences. Even though, a rotary file tool, that is deployed for permanent teeth for adults, is deployable for endodontic surgery for primary teeth in child patients, however, it is pertinent to note that, the rotary file tool deployed for root canal treatment of adult tooth, if used for child patient(s), may cause severe and irreparable damage to the delicate root canal structure of a child's tooth.

This issue must be viewed seriously in case of primary teeth, as it can interfere with the eruption of permanent teeth. File breakage in primary teeth can alter the path of eruption of permanent tooth bud. Rotary file breakage can occur without warning, regardless of the brand of the file, its design, age, length, taper (or) size. In the above-mentioned context, it will be amply clear to a person skilled in the art that, there is a need in the art for a device that is especially suited for the anatomical needs of the narrow root canal structure of the child's tooth.

It will also be amply clear to a person skilled in the art that, there is a need in the art for a device that enables the easy retrieval of the file tool in the event of rotary file breakage, so that it does not interfere with the eruption of permanent teeth. It will also be amply clear to a person skilled in the art that, there is a need in the art for a device, that is especially suited for the narrow root canal of a child such that, it does not impede the further growth and development of the permanent teeth.

It will also be amply clear to a person skilled in the art that, there is a need in the art for a device, that is especially suited for the smooth entry of the device into the narrow root canal of a child, so as to enable a surgery, without injury or perforation to the primary teeth of the child patient.

It is also amply clear to a person skilled in the art that, there is a need in the art for a device, whose cross-section is sufficiently adjusted so that, even minor cutting action of the files is sufficient for cleaning and shaping the root canal space in primary teeth.

It is also amply clear to a person skilled in the art that, there is a need in the art for a device, which has specific dimensions which are adaptable to fit any primary teeth.

It is also amply clear to a person skilled in the art that, there is a need in the art for a device, whose working area should be controlled to a specific length, which suits the total length of the primary tooth. It is also amply clear to a person skilled in the art that, there is a need in the art for a device, which assists in root canal treatment, in a faster and easier manner, for primary tooth. It is also amply clear to a person skilled in the art that, there is a need in the art for a device, which is less cumbersome than tooth extraction method, conventionally deployed for primary tooth of a child patient. It is also amply clear to a person skilled in the art that, there is a need in the art for a device, which causes the root canal treatment for primary teeth to become more cost-effective, than the conventionally deployed tooth extraction mode for children.

It is also amply clear to a person skilled in the art that, there is a need in the art for a device, which enables root canal treatment without perforation of the root canal in the context of primary teeth. It is also amply clear to a person skilled in the art that, there is a need in the art for a device, which can enable performance of root canal treatment in primary teeth with a single instrument. It is also amply clear to a person skilled in the art that, there is a need in the art for a device, which can enable performance of root canal treatment in a less time consuming manner.

OBJECTANDSTATEMENTOFINVENTION: In the above-mentioned context, it is an objective of the present invention to provide a device that is especially suited for the anatomical needs of the narrow root canal structure of the child's tooth such that it does not impede the further growth and development of the permanent teeth. Still further, it is an objective of the present invention to provide a device that is especially suited for the smooth entry of the device into the narrow root canal of a child, so as to enable a surgery without injury or perforation to the primary teeth of the child patient.

Furthermore, it is an objective of the present invention to provide a device, which enables the easy retrieval of the file tool in the event of rotary file breakage, so that it does not interfere with the eruption of permanent teeth. File breakage in primary teeth, can alter the path of eruption of permanent tooth bud. Further, it is an objective of the present invention to provide a device whose cross-section is sufficiently adjusted so that, even minor cutting action of the files is sufficient for cleaning and shaping the root canal space in primary teeth.

Yet another objective of the present invention is a device, which has specific dimensions which are adaptable to fit any primary teeth.

Yet another objective of the present invention is a device, whose working area can be controlled to a specific length, which suits the total length of the primary tooth.

Yet another objective of the present invention is a device, which assists in root canal treatment, in a faster and easier manner for primary tooth. Yet another objective of the present invention is a device, which is less cumbersome than tooth extraction method, conventionally deployed for primary tooth of a child patient.

Yet another objective of the present invention is a device, which causes the root canal treatment to become more cost-effective, than the conventionally deployed tooth extraction mode for children.

Yet another objective of the present invention is a device, which enables root canal treatment without perforation of the root canal in the context of primary teeth. Yet another objective of the present invention is a device, which can enable performance of root canal treatment in primary teeth with a single instrument.

Yet another objective of the present invention is a device, which can enable performance of root canal treatment in a less time consuming manner. The present invention with its attendant advantage(s) and feature(s) fulfills the above- mentioned objective(s). The present invention comprises a pediatric rotary endodontic file used to perform root canal treatment in primary teeth. "Primary teeth" as referred to herein and elsewhere in the document refers to "milk teethi.e., teeth that are formed initially. This invention helps to perform root canal treatment in primary teeth with a single instrument. It also has a shear region, which facilitates easy removal of broken instrument from the root canal space. It also has a dual taper, which prevents occurrence of strip perforations.

File breakage in primary teeth can alter the path of eruption of permanent tooth bud. Rotary file breakage can occur without warning, regardless of the brand of the file, its design, age, length, taper (or) size. In order to compensate this drawback of the rotary files, the diameter at the shank region of the rotary file in the present invention is reduced to a suitable diameter enabling the rotary file to separate at its shank region. This will facilitate easy retrieval of the broken instrument. This shank region is also surface treated with a special material to increase the performance and longevity of the file. The cross section of the file is not taken into consideration. Even minor cutting action of the files is sufficient for cleaning and shaping the root canal space in primary teeth.

SUMMARY OF THE INVENTION:

The present invention discloses a pediatric rotary endodontic file. The rotary endodontic file, as embodied in the present invention, is employed to perform root canal treatment, in primary teeth of children. This invention helps to perform root canal treatment, in primary teeth with a single instrument. It also facilitates easy removal of broken instrument from the root canal space, so that, it does not interfere with the eruption of permanent teeth, at a later point of time. The rotary endodontic file as embodied in the present invention, has a dual-taper namely, 2% for 7 mm, 4% for 7mm distance which means 50% of the length of the working area is devoted to 2%, taper and 50% of the length of the working area is devoted to 4% taper. The dual-taper prevents occurrence of strip perforations. The rotary endodontic file is made, via a mould, which has the shape, in which material is taken from both sides. The dimension of safe breakage region/ shear region is 0.45 mm diameter, and 1mm - 3mm in length. The dimensions of the tapering, the value of the length distribution for each type of taper namely 2% and 4%, the manufacturing method have all been especially adapted to be suitable for the anatomical needs of the narrow root canal structure of the child's tooth.

The device is especially suited for the narrow root canal of a child such that, it does not impede the further growth and development of the permanent teeth at a later point of time. The present invention utilizes a standard diameter at its tip of the file, non-cutting edge at one millimeter from the tip, dual taper in its working area, controlled working length and shank region. The goal of the newly invented pediatric endodontic rotary file is to introduce efficient and standard root cleaning and shaping process for primary teeth. This is designed in consideration with the morphology, length and curvature of the primary teeth roots. This pediatric rotary file will help the clinicians perform root canal procedure in a faster and easier manner.

BRIEF DESCRIPTION OF DRAWINGS:

The detailed description in conjunction with the accompanying drawing(s) provides a clear understanding of the invention. Persons skilled in the art will appreciate that, variations and combinations of the concept and components of the invention disclosed herein, are also to be treated as a part of the present disclosure.

Figure 1, is a diagram illustrating the rotary file in accordance with an embodiment of the present invention;

Figure 2, is a sectional diagram of the human primary tooth, clearly demarcating the various portions of the human primary tooth;

Figure 3, is a diagram illustrating the preparation of root canal space;

Figure 4, is a diagram illustrating the complication in perforated primary tooth;

Figure 5, is a diagram illustrating the root of the primary tooth with approximate enlargement required at different levels;

Figure 6, is a diagram illustrating the rotary file with 2% taper and 4% taper and its diameter at every 1mm. Figure 7, is a diagram illustrating the cross sectional view of human primary tooth with the file in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

It is a matter of common knowledge that, as a consequence of the travel, and other allied activities associated with day-to-day living, dietary habits have undergone a transformation. Further, materials that are used for processing the foodstuffs are also chemicals, and not natural ingredients, as used in the pre-industrial era. As a result, it is further observed that, due to consumption of processed foodstuffs, dental hygiene has become of secondary importance.

Structurally, the roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness. Enamel is the outer layer of the exposed tooth. Enamel is almost entirely composed of calcium salts. It is a hard, thin, translucent layer of calcified substance that envelopes and protects the dentin (the main portion of the tooth structure) of the crown of the tooth. It is pertinent to note that the tooth that is formed initially in children is termed as 'primary tooth" in dental parlance. Continual consumption of processed foodstuffs and improper dental hygiene sets the path for "tooth decay".

The present invention is a rotary dental file tool, capable of performing root canal treatment in "primary tooth". It is very well apparent to a person skilled in the art that, conventional methods do not reveal a method to perform the root canal treatment for adults to be performed in children, using a device as embodied in the present invention so that the growth and development of the "permanent teeth" is not impeded. These rotary instruments used on adults are too lengthy to be used in children. Hence shorter rotary instruments which should have a total length in the range of 16-20mm are required for primary teeth. This will also facilitate an easy access for preparing the root canals in a child's posterior teeth. The various features and advantages of the present invention are brought out in a manner apparent to a person skilled in the art in the description in conjunction with the enclosed drawings. In this context, the structure of the primary and subsequently formed permanent teeth is explained in the enclosed drawings. Figure. 1 is a diagram illustrating the pediatric endodontic rotary file (3) of total length (L) 18mm, for root canal space (18) cleaning and shaping in primary teeth (A). The file (3) is made of a metallic material. The file is typically fabricated from a Nickel-Titanium alloy known by the trade name Nitinol (or) by scientific formula NITI. File (3) composed of Nickel- Titanium possesses superior flexibility, fracture and torsional resistance properties compared to standard stainless steel files.

The newly invented pediatric endodontic rotary file (3) has a working area of 14 mm. The safe end at the tip (1) is 1 mm in length and the cutting region (2) measures 13mm. The cutting region (2) of the instrument has a dual taper; 2% from the tip up to 7mm termed herein and elsewhere in the present disclosure as upper region (4) and 4% from 8mm to 14 mm termed herein and elsewhere in the present disclosure as cervical region (5). The upper region (4) further comprises apical region (4a) which measures atleast 4.6 mm. This cutting region (2) performs the cutting action and removes the tooth material. This taper controls the enlargement of root canal (12). The file (3) also has a shank region (6) and a shear region (7). The shear region (7) having length in the range of 1mm to 3mm. The taper in the cervical region (5) of the file (3) enables to form cervical enlargement (22) which facilitate to fill the apical level (31) comfortably in the prepared root canal space (18) and an apical region (4a) of 2% taper enables avoiding perforations (21) occurring even in the middle level (32) of the root canals (12) in primary teeth (A). Further, a head region is provided above the shank region to hold the rotary file.

The shank region (6) comprising a safe breakage region embodied as shear region (7) will facilitate the rotary file (3) to break above the orifice of the root canal (12). It prevents the safe end tip (1) of the file (3) from becoming irreversibly embedded in a human primary tooth (A) after file breakage. The broken component can be easily gripped and retrieved from the root canal (12). Figure. 2 is a sectional diagram of the human primary tooth (A) clearly demarcating the various portions of the human primary tooth (A), alternatively termed as "milk tooth". In this context, it is observed that a human tooth has a crown (11) and a root (12). It has various structures, namely enamel (13), dentin (14), pulp (15) and cementum (16). Enamel (13) is the outer covering of the crown (11) of the tooth whereas, cementum (16) covers the roots (12). Dentin (14) is a hard, elastic and a vascular tissue, which lies next to the enamel (13) in the crown (11) and cementum (16) in the roots (12). Both enamel (13) and cementum (16) are firmly interlocked with dentin (14). Pulp (15) is present in the crown (11) and the roots (12) beneath the dentin (14) of the teeth. It is highly vascular and contains soft connective tissue.

Figure.3 is a diagram illustrating the preparation of root canal space (18) with rotary file (3) in accordance with an embodiment of the present invention, the length (L) of the pediatric rotary file (3) is 18mm. The file comprises cutting region (2) of 13mm length and safe end tip (1) of 1mm length. The cutting region (2) further comprises upper region (4) and cervical region (5). The upper (4) region has 2% taper for 7mm and cervical region (5) has 4% taper for the remaining 7mm. The upper region further comprises, apical region (4a), which is atleast 4.6 mm in length. In root canals (12) of primary teeth (A), to avoid perforations (21) at the apical level (31) the rotary instruments should have a taper of 2% or less. In the newly invented pediatric rotary instrument (3) the apical region (4a) has 2% taper. This 2% taper is further continued to 7mm in the pediatric rotary instrument (3) to avoid perforations (21) occurring even in the middle level (32) of the root canals (12) in primary teeth (A). The cervical region (5) of the file has a 4% taper, which will produce the cervical enlargement (22). This cervical enlargement (22) will facilitate the operator to fill the apical level (31) in the prepared root canal space (18).

This diameter is calculated on the basis of:

1. Initial minor enlargement of the root canal space (18) with hand files in order to attain patency of the canal before using rotary files.

2. Root canal diameter of the primary posterior teeth.

3. Dentin thickness of the primary posterior teeth.

Figure.4 is a diagram illustrating the complication in perforated primary tooth (A); Complications of perforation in primary teeth include the following;

1. Once perforations (21) occur, the irrigants/solutions (41) or filling material (42) will leak through the perforated (21) space, leading to pain and infection.

2. Excess removal of the remaining dentin (14) will weaken the tooth (A).

3. The material (42) leaked through the perforated (21) area may hinder the eruption or alter the path of the erupting permanent tooth (B) leading to malocclusion.

According to Figure 5, the approximate diameter required for rotary instruments (3) to perform safe root canal procedures in primary molar teeth (A) at different levels are 0.25-0.35mm at its apical level (31), 0.35-0.45mm at its middle level (32) and 0.55-0.65mm at its cervical level alternatively termed as coronal level (33). According to the above-mentioned requirement, the file (3) of the present invention is made and it meets all the desired functions. Figure 6 of the present invention illustrates the rotary file (3) with 2% taper termed as upper region (4) further comprising apical region (4a) and 4% taper termed as cervical region (5) and its diameter at every 1mm interval. The length of the working area, comprising a cutting region (2) of 13mm and a safe end tip (1) of 1mm, is 14mm, wherein, the said cutting region (2) comprises 2% taper for 7mm (4) and 4% taper for the remaining 7mm (5). In root canals (12) of primary teeth (A), to avoid perforations (21) at the apical level (31), the rotary instruments should have a taper of 2% or less. In the present pediatric rotary file (3), the apical region (4a), which is atleast 4.6 mm has 2% taper, wherein the 2% taper is further continued to 7mm to avoid perforations (21) occurring even in the middle level (32) of the root canals (12) in primary teeth (A). The cervical region (33) of the file (3) has a 4% taper, which will produce the cervical enlargement (22). This cervical enlargement (22) will facilitate the operator to fill the apical level (31) in the prepared root canal space (18). The diameter of the rotary file (3) at every 1 mm interval of the cutting region (2) from the top of the cervical region (5) to the tip of the apical region (4a) is between 0.69mm and 0.25mm, more particularly the diameter at every 1mm interval is 0.69, 0.65, 0.61, 0.57, 0.53, 0.49, 0.45, 0.41, 0.37,0.35, 0.33,0.31, 0.29, 0.27 and 0.25. Referring to Figure.7- the use of pediatric endodontic rotary file (3) can be understood by viewing the partial cross section of a tooth. The tooth (A) includes a supporting root structure within each root (12) and is known as root canal space (18). The root canal space (18) contains the circulatory and neural system of the tooth (A). The fibers (Nerves and Blood vessels) enter the tooth at the tip of each of its root(17) and extend through the narrow canal (12) until it reaches the pulp chamber (15), which is present adjacent to the crown (11) portion of tooth (A). When the pulp tissue (15) becomes irritated due to variety of reasons like caries, traumatic injuries, the tissue becomes diseased and generates severe pain. Root canal therapy involves removing the diseased tissue from the canal (12) and sealing the canal space (18) after treatment. The first step in performing a root canal procedure is to drill into the tooth (A) and locate the root canal (12). A hand file is used to attain the patency for the canal. The dentist next uses an endodontic rotary file (3) to remove dead, decayed material from the canal (12). The aim is to remove all the debris and shape the canal so that, the walls of the canal (19) remains clean aiding in proper filling of root canal space (18). The root canal space (18) is filled with a paste like material in the primary teeth (A). After complete filling, the material shouldn't have any leakage to the surrounding tissue of the tooth (A). The root canals (12) of primary teeth (A) are narrow and severely curved. The instrument, which is used to prepare the root canal, should have the ability to shape the root canal space (18) and should fulfill the requirements needed by the dentist to perform a successful root canal treatment. The amount of enlargement of root canal space (18) is minimal for primary teeth (A) when compared to permanent teeth (B). The working area of a pediatric endodontic rotary file (3) is short irrespective to the taper of the file (3). The Nickel-Titanium alloy files offer superior flexibility and torsional properties as compared to stainless steel files; the Nickel- Titanium files are prone for breakage. The solution to the breakage problem is to facilitate file breakage at the shank region (6). Shank region (6) comprises a shear region (7) as it can facilitate easy removal of broken instrument from the root canal space (18). Further, due to the low modulus of elasticity of the Nickel-Titanium alloy, the tip doesn't lock tightly into the canal (12). The total length of the file (3) is about 18mm (from the safe end tip till the end of shank region).

Accordingly, An pediatric endodontic rotary file (3) for root canal space (18) cleaning and shaping in primary teeth (A) comprising: a shank region (6) having a shear region (7) to facilitate the rotary file (3) to break above the orifice of the root canal (12) and prevents the safe end tip (1) of the file (3) from becoming irreversibly embedded in a human primary tooth (A) after file breakage; cutting region (2) further comprising cervical region (5) of the file (3) is provided with a 4% taper for about 7mm to form cervical enlargement (22) which facilitate to fill the apical level (31) comfortably in the prepared root canal space (18), and an upper region comprising an apical region (4a) having 2% taper to avoid perforations (21) occurring even in the middle level (32) of the root canals (12) in primary teeth (A); a head region is provided above the shank region (6) to hold the rotary file (3). The working area of the file (3) is about 14 mm in length. The shank region (6) is between head region and cervical region having length about 4mm which further comprising a shear region (7) having length in the range of 1mm to 3mm is between shank region (6) and cervical region (5). The cutting region (2) is about 13 mm in length. The cervical region is between shank region (6) and upper region (4) provided with 4% taper having 7mm length. The apical region (4a) is below the cervical region (5), having 2% taper with 7mm length until the safe end tip (1) having 1mm length. The shear region (7) has a diameter measuring 0.45 mm and length in the range of 1 mm to 3mm. The diameter of the rotary file (3) at every 1 mm interval of the cutting region (2) from the top of the cervical region (5) to the tip of the apical region (4a) is between 0.69mm and 0.25mm, more particularly the diameter at every 1mm interval is 0.69, 0.65, 0.61, 0.57, 0.53, 0.49, 0.45, 0.41, 0.37, 0.35, 0.33, 0.31, 0.29, 0.27 and 0.25, wherein dental file (3) is typically fabricated from a Nickel-Titanium alloy.

It will be obvious to a person skilled in the art that the description of the rotary file as embodied in the present invention is provided for better understanding of the invention. However, it will also be obvious that any combination, variation of the present invention would be encompassed under the scope of the present invention.