”Deciduous teeth” comes from the Latin phrase ”decidere,” which means ”to fall out.” Exfoliation occurs when teeth get soft and fall off, replacing them with permanent dentition, similar to how flower petals and leaves do. The most critical issue in pediatric dentistry is the early loss of primary molars that are necrotic due to caries or other factors, including trauma.

Primary teeth plays an indispensable role in the dental and facial development. The dentofacial skeletal complex is adversely affected in terms of soft tissue support, occlusion, full dentition development, and esthetics. Also, the most unpleasant consequence of untreated dental caries in children is pulp involvement.

Over and above, they guide the eruption of permanent teeth . Hence, preserving the primary teeth in its position without any infection is of utmost importance. For the management of necrotic primary teeth, pulpectomy remains as the first choice of treatment.

The main goals of root canal cleaning and shaping are to eradicate bacteria containing soft and hard tissue, create a conduit for irrigation to the apical third, create space for instrumentation, perform future obturation, and maintain the integrity of radicular structures. Therefore, cleaning and contouring the root canals will remove the irrigation pathway, which will ensure the success of the pulpectomy. Reamers, files, burs, sonic tools, mechanical tools, and nickel- titanium (Ni-Ti) rotary file systems are used to prepare root canals.

This endodontic treatment is done to debride the tortuous primary root canals and maintain it in a non- pathologic condition until exfoliation.

Rotary instrumentation has made a quantum leap in the field of endodontics. These changes lead to introduction of rotary endodontics in pediatric dentistry. 

Barr et al. (2000) carried out the first investigation to demonstrate the application of NiTi rotary files in primary molars. The most remarkable feature of using NiTi rotary instruments is that it produced a predefined conical shaped canals with exceptionally reduced instrumentation time.

With fewer appointments, Rotary has increased workability because a child’s behavior is significantly impacted by the length of each appointment.

It was also reported that it would be more effective if pulpectomy in primary tooth is performed with an exclusive paediatric rotary file system with revised length, taper and tip diameter.

Specialized pediatric rotary files with additional modifications, like gold-treated files, heat-treated files with a TiO coating, and files with CM, are now readily accessible for use in primary teeth that have a length from 16 to 18 mm.

Various rotary file systems are available in pediatric dentistry such as: Kedo S, Kedo SG, Kedo SG Blue, Kedo S Square, Pedo Flex, Pro AF Baby Gold, Prime Pedo endo kit.

In 2017, Jeevanandan introduced the Kedo-S rotary file created especially for primary teeth. Kedo-S files comprised five generations which are Kedo-S, Kedo- SG, Kedo-SG blue, Kedo-S-Square, and Kedo-S-Plus. The first generation is made up of three Nickel-titanium (Ni-Ti) files (D1, E1, U1) that have a 12 mm working length and a variable taper to allow effective root canal preparation without over-instrumenting the delicate primary root canal wall. In 2019, a single- file rotary system, Kedo-S-Square file, was invented which consists of two files, A1 for primary anterior teeth & P1 for posterior primary teeth. Kedo-S-Square file has a Ni-Ti heat-treated dual-core with a titanium-oxide coating. Also, it has a unique feature as a variably vari- able taper design and 16 mm working length with a non- cutting tip.

Kids-e-dental has introduced new rotary filing systems, notably the Kids-e-dental rainbow files. To make Kids-e-Files flexible and long-lasting, a nickel-titanium alloy is heat-treated and surface-treated. They can navigate through curved root canals due to their triangular cross section.

ProAF baby comprises five file sequences and is made of heat- treated nickel titanium-controlled memory wire. They maintain a constant taper of 4% and 6% depending on the file sequence used. These files were designed to be similar to the file sequence used for permanent teeth.

The Neoendo flex orifice enlarger measures 19mm in length and has a 8% taper. The use of files with appropriate characteristics such as length, taper, and tip size customized to the root canal morphology of primary teeth is crucial for achieving successful endodontic treatment.

Another paediatric rotary system, the Prime PedoTM, consists of four files: Starter, P1, P2, and Endosonic file. The Prime PedoTM file system includes the Starter file (8% taper, 16 mm), P1 file (#15, 6% taper, 18 mm), P2 file (#25, 6% taper, 18 mm), and endodontic file (2% taper, 18 mm). The length markings on the file are as follows: 12 mm up to the flutes, 13 mm stopper above the flutes, 14 mm marker ring present, and 15 mm above this mark, with a marker ring at 16 mm. As a result, a ruler or scale is not required to align the stopper for repeatedly setting the working length. The Prime PedoTM files have a gold treatment and controlled memory, which allows them to be centered in the curved canals of primary molars.

However, there is paucity in the studies on the comparison of rotary files that are used exclusively for primary teeth. Till date a few clinical trials have been conducted to demonstrate the efficacy of the various pediatric rotary file systems, and hand file systems.

However, there is no comparative study in literature, that have been conducted to evaluate the instrumentation time, taper and quality of obturation using pediatric rotary file systems and modified rotary file systems.

Hence, the present short study will be undertaken to comparatively evaluate the instrumentation time, taper of the canal clinically and the quality of obturation radiographically following the cleaning and shaping using four different rotary file system and also to evaluate and compare the intracanal 3D shape, debris index and smoothness of the prepared canal using these file systems.

Purpose of this research is to comparatively evaluate the instrumentation time, taper of the canal clinically and the quality of obturation radiographically. With an increasing number of clinicians using different rotary systems in primary tooth pulpectomy, it is important to know which rotary system provides the best clinical outcomes for obtaining good- quality obturation.

Therefore, this research will help the clinicians to choose the effective paediatric rotary file system  amongst the five different rotary file systems which will further improve the success rate of the management of the pulpal therapy of the deciduous teeth.