The Use of the K3 Orifice Openers In Primary Teeth Preparation



To illustrate through a series of 2 clinical cases the advantages of using the K3 Orifice Openers in pulpectomy of primary teeth


Root canal preparation is still the most time consuming part in root canal treatment. Especially when dealing with children and primary teeth. The Ni-Ti rotary files especially the K3 17mm orifice opener (ie-OO) have the advantages of a fast reliable shaping technique.

– Pulpectomy in primary teeth.

– Using the Ni-Ti rotary files, the K3 orifice openers

– 90% of the cases, single file preparation.

The objectives of pulp treatment in primary teeth are repair and healing of the residual pulp tissue in histological terms and a well-functioning tooth until normal exfoliation (Ingegerd Mejre 2003).

Root canal treatment is indicated when the pulpal tissue becomes irreversibly inflammed or necrosis occurs. When the primary tooth is still of a certain value, such as for maintainence of space for eruption of the permanent teeth root canal treatment should be considered.

The preparation of the root canal space takes the most time of the entire endodontic procedure. When dealing with the child, time is of the essence and therefore hand filing often is not the most practical solution especially when dealing with a management consideration.

The K3 Orifice Openers (OO) consists of 3 files of 0.25 ISO tip and 3 different tapers, .08 taper, .10 taper and the .12 taper. Different lengths are also available varying from 17mm, 21mm and 25mm. The most interesting length in the treatment of primary teeth is the 17mm .12 orifice operner due to the limitation of accessibility in pedodontic treatment. They may be used, in 90% of the cases, as a single file preparation for every root depending on the anatomy of the canal.

In case of large canals the .12 taper, .25mm tip may be used to the working length, in medium sized canals the .10 taper, .25mm tip and in narrow canals the .08 taper .25mm tip will reach the working length. In some cases of apical curvature the 08 taper .25mm tip may be used to prepare the apical part in case a larger taper was previously used in the coronal sections of the root canal.

The K3 OO are very safe, highly resistant to separation and maintain the original shape of the root canal (Bergmans et al 2003) with minimal risk of strip perforation especially in such small and narrow canals.


A six-year-old patient was suffering from pain during the night and pain upon percussion on tooth #85. The radiograph, (Fig. 1), showed an M-O-D caries exposing the pulp. No sign of internal or external radicular resorption was seen. The tooth is at stage number 2 (stable). An indication for pulpectomy.

The K3 Orifice Opener 17mm 25 T 12 was chosen to perform the shaping of the canals since they are straight with no sign of apical curvature or narrow canal in the mesials.

The rubber dam was placed the access cavity was achieved, the working length was taken and within then 2 minutes the canals were prepared with a copious irrigation. Obturation using Zinc oxide Eugenol paste was completed (Fig. 2).


A five-and-a-half-year-old patient presented for regular check up and deep caries was observed on the bite wing radiograph on tooth #85 (Fig. 3). No pain to percussion or biting was reported. Once the cavity was eliminated the rubber dam was placed due to the risk of pulp exposure, and indeed the pulp was exposed, once all the pulp chamber was free from any pulp tissue with a clean section at the root entry with a net cut, pulp fixation was achieved with Formocresol on 3 repetitive temptations, but bleeding was still occurring revealing an inflammatory status of all the pulp tissue including the roots. The decision was taken to perform a pulpectomy.

The K3 Orifice Opener 17mm .12 taper, .25mm tip was chosen to perform the shaping of the distal root and the .10 taper, .25mm tip was used for the mesial canals since they showed an apical and middle curvature. Obturation was completed using Zinc oxide Eugenol paste (Fig. 4).


Pulpectomy and canal shaping of primary molars is often considered impractical because of the difficulty of obtaining adequate access to the root canals in the small mouths of children especially for time consuming procedures.

Root canal preparation is still the most delicate and time consuming part in root canal treatment, especially when dealing with children. The Ni-Ti rotary files especially the K3 OO have the advantages of having a 17mm length which is the standard for pedodontic cases. After opening into the pulp chamber, removing the coronal pulp and locating the root canals, the radicular pulp must be removed and the canals filed in the same visit.

Hopefully this will bring the attraction on applying the new ideas and armamentarium of modern endodontics and applying it to pedodontics for a faster, less traumatic treatment.

Dr Philippe Sleiman is an instructor at the Lebanese University Dental school. email:


1.Bergmans L, Cleynenbreugel J.Van, Beullens M, Wevers B, Van Meerbeek & Lambrechts P. Progressive versus constant tapered shaft design using Ni-Ti rotary instruments. International endodontic journal 36: 288-295.

2.Ingegerd Mejre, Texbook of Endodontology, Gunnar Brgenholtz Preben Hrsted-Bindslev, Claes Reit. Blackwell Munsgaard. 2003