WO2007119257A1

WO2007119257A1 - Root canal filling carrier

Info

Publication number: WO2007119257A1
Application number: PCT/IT2007/000272
Authority: WO
Inventors: Amedeo Pagliarini
Original assignee: Universita' Degli Studi Di Ferrara
Priority date: 2006-04-14
Filing date: 2007-04-12
Publication date: 2007-10-25
Also published as: EP2007308A1; ITRM20060215A1

Abstract

The invention relates to canal filling carrier (1), said carrier providing a front portion (handle) (2), a shank portion (4) and a conical end portion (3), said carrier being characterised in that said end portion (3) has a tapering of at least 0.06, and in that said end portion (3) is comprised of a series of frusto-conical elements having their base faced toward the carrier end opposed with respect to the front portion (handle) (2), with a diameter decreasing toward said end of the support opposed with respect to the conical end portion, said carrier being coated by a alpha behaviour gutta-percha.

Description

ROOT CANAL FILLING CARRIER

The present invention relates to a root canal filling carrier. More specifically, the invention relates to a carrier of the above kind permitting improving the canal filling technique.

As it is well known, canal filling aims maintaining for a long time healthy condition of periapical tissues of teeth subjected to endodontic treatment.

It is nowadays universally accepted in the dentistry field that best material for canal filling is thermo-plasticised gutta-percha.

Gutta-percha is commercially available in the form of alpha isomer prevailingly mixture of beta isomer prevailingly mixture- Comparing the two kind of gutta-percha, the one with alpha behaviour has a higher fluidity, a higher adhesivity and a lower melting and softening point, a lower shrinking and a longer workability time with respect to the beta behaviour.

High adhesivity of alpha behaviour gutta-percha limits possibility of manual condensation, since it sticks to pluggers.

On the contrary, high fluidity of alpha behaviour gutta-percha confers to the same better sealing properties due to the lower difficulty of penetration within the accessories canals. The last feature made it necessary putting on the market devices able employing alpha phase gutta-percha without being it necessary condensing employing traditional Shilder method. Most known among these devices are:

- Obtura syringe, useful only for speeding down-packing of the two third corona teeth, since in case it is used alone would not permit a suitable apical control;

- Microseal system; - Thermafil system, comprised of pluggers comprised of a plain liquid crystal plastic carrier, coated by gutta-percha, to be heated and plasticised when ready to be used, coupling advantages deriving from the alpha behaviour gutta-percha with the high rate in making canal filling.

However, the above Thermafil system, which is appreciated for its simplicity and use rate even in canals with very wide curves, has two disadvantages.

First, gutta-percha is not always suitably condensed at the apical level, so that it is not always possible obtaining filling of lateral canals. Thus, thermo-plasticised gutta-percha is very fluid, rises in the coronal direction and plastic plain core cannot oppose to reflux.

Further, plastic carrier is too rigid, so that it does not remain suitably centred in the canal, thus impacting against the dentinal walls, thus baring of the thin gutta-percha layer, this phenomenon being known as stripping.

In view of the above, the Applicant has realised an improvement to the Thermafil system, permitting obviating to the above mentioned drawbacks and realising new pluggers with better performances.

It is therefore specific object of the present invention a root canal filling carrier, said carrier providing a front portion (handle), a shank portion and a conical end portion, said carrier being characterised in that said end portion has a tapering of at least 0.06, and in that said end portion is comprised of a series of frusto-conical elements having their base faced toward the carrier end opposed with respect to the front portion, with a diameter decreasing toward said end of the support opposed with respect to the conical end portion, said carrier being coated by a alpha behaviour gutta-percha. Preferably, according to the invention, said shank portion is smooth, with a stop close to the transition with said conical front portion (handle).

Particularly, said stop is comprised of silicon material.

Still according to the invention, said carrier is comprised of Delrin^®.

Furthermore according to the invention, said shank portion has a thickness of 1 mm.

Still according to the invention, said end portion provides 15 frusto-conical elements, preferably each one high 0.8 mm. Always according to the invention, diameter of the larger base of the last of the frusto-conical elements changes while the identification number of the plugger, corresponding to the ISO standardisation value of the diameter at the tip of the endodontic instruments.

The present invention will be now described, for illustrative but not limitative purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein: figure 1 is a schematic view of a root canal filling carrier according to the invention not finished; and figure 2 is a perspective view of a root canal filling carrier according to the invention. Observing now the enclosed drawings, it is shown a carrier according to the invention, generically indicated by reference number 1 , presently the preferred embodiment, but the same results could be obtained by different solutions with respect to those described, always included in the scope of the invention. Carrier 1 for pluggers shown in the figures has been comprised of Delrin^® (sold by DuPont, Wilmington, DE, USA), a material already used for realising cardiac valve prosthesis and hip joint prosthesis.

It is a fully biocompatible material with elasticity almost five times higher than that of the Liquid Crystal Polymer usually employed for Thermafil carriers.

Structurally, carrier 1 has a particular tapering 2 (0.06) based on supposition that filling system according to the invention must work within canals not prepared manually, but rather by Ni-Ti tools with 0.06 improved tapering. In the standard Thermafil systems, with a tapering of 0.04, problems exist in centring the canal carrier 1 in the root.

Thus, gutta-percha thickness between carrier 1 and canal should be uniform, thus compensating dimension change due to the cooling of gutta-percha all along the canal surface.

As it can be noted in figure 1, in the embodiment shown corresponding to about 12 mm, on the end portion of the carrier 1 it is provided succession of a series of frusto-conical elements (15 in the embodiment shown) faced with the larger base toward the carrier 1 apex

(each high 0.8 mm in the embodiment shown).

Diameter of the larger base of the last frusto-conical element varies with the change of the plugger identification number and corresponds to the ISO stadardisation number of the diameters at the tip of the endodontic instruments (e.g. plugger n⁰ 20 = 0,20 mm; n° 25 =

0.25mm; n⁰ 30 = 0. 30mm; n° 35 = 0. 35mm; n° 40 = 0.40mm; n° 45 =

0.45mm) while the other increase the base diameter maintaining the 0.6 tapering.

Carriers 1 according to the invention have been realised starting from Delrin^® bars having a diameter of 9 mm, thanks o a computer controlled lathe, controlled by an optical verifier (PJ250c model, Mitutoyo, Kawasaki, Japan).

Observing now shank 4 of carrier 1 , it is noted that, while in the standard Thermafil system reference rings are provided in order to set the working length, but that instead often prevent positioning the silicone stop (see figure 2), in the inventive solution shank diameter 4 has been increased, eliminating the plastic references so that setting of the silicone stop 5 is due only to the friction force.

Carriers 1 thus obtained are coated by alpha behaviour gutta- percha with the aid of a mould suitably realised (see figure 2).

By the solution according to the invention described in the above a device is obtained reducing the stripping risk.

Possible stripping is in any case lower than that with the original system, particularly for bigger pluggers. Furthermore, alpha behaviour gutta-percha is in any case better condensed at the apical level.

Under a practical point of view, teaching easiness of the filling technique is identical to the one with the known Thermafil system, execution time being the same. The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.

Claims

1. Canal filling carrier, said carrier providing a front portion (handle), a shank portion and a conical end portion, said carrier being characterised in that said end portion has a tapering of at least 0.06, and in that said end portion is comprised of a series of frusto-conical elements having their base faced toward the carrier end opposed with respect to the front portion, with a diameter decreasing toward said end of the support opposed with respect to the conical end portion, said carrier being coated by a alpha behaviour gutta-percha.

2. Carrier according to claim 1 , characterised in that said shank portion is smooth, with a stop close to the transition with said conical front portion (handle).

3. Carrier according to claim 2, characterised in that said stop is comprised of silicon material.

4. Carrier according to one of the preceding claims, characterised in that it is comprised of Delrin^®.

5. Carrier according to one of the preceding claims, characterised in that said shank portion has a thickness of 1 mm.

6. Carrier according to one of the preceding claims, characterised in that said end portion provides 15 frusto-conical elements.

7. Carrier according to one of the preceding claims, characterised in that each frusto-conical element is high 0.8 mm.

8. Carrier according to one of the preceding claims, characterised in that diameter of the larger base of the last of the frusto- conical elements changes while the identification number of the plugger, corresponding to the ISO standardisation value of the diameter at the tip of the endodontic instruments.

9. Carrier according to each one of the preceding claims, substantially as illustrated and described.