WO2010144064A2

WO2010144064A2 - Tube guiding root canal instruments to shape the root canals from apical to coronal during apical resection in dental surgery

Info

Publication number: WO2010144064A2
Application number: PCT/TR2010/000092
Authority: WO
Inventors: Mehmet Baybora Kayahan
Original assignee: Mehmet Baybora Kayahan
Priority date: 2009-05-13
Filing date: 2010-05-07
Publication date: 2010-12-16
Also published as: TR200903710A2; WO2010144064A3

Abstract

A tube (1) curved in a manner to form an α angle in order to provide direction for more effective use of canal instrument (3) in small bone cavities during apical resection applied in endodontic surgery of dentistry and shaping canals from root apical towards coronal in root canals not allowing access through coronal and advancement up to the depth desired in coronal direction, which is located in resected tooth apical and guide location of canal instrument (3). The said α angle is between 90° and 120° and the said tube (1) is manufactured from stainless steel or plastic material of cylindrical structure as casting.

Description

TUBE GUIDING ROOT CANAL INSTRUMENTS TO SHAPE THE ROOT CANALS FROM APICAL TO CORONAL DURING APICAL RESECTION IN DENTAL

SURGERY

The Related Art

The invention relates to retroshaping tube functioning as a guide in shaping root canals from apical to coronal during apical resection (cutting root end) procedure; particularly in root canals not accessed through coronal way (existence of post or zirconia crowns).

Background of the Related Art

Endodontics is a branch of dentistry, which deals with pulp diseases and orthograde (through coronal) or retrograde (from root apex) therapies. The purpose of endodontic therapy is to clean, shape and fill the root canal system hermetically. The primary approach in root canal therapy is to perform the treatment by orthograde

(coronal) way. However, micro-organisms can not always be eliminated by conventional canal therapy methods which are done through orthograde way because of the complex root canal morphology and/or various complications.

Endodontic surgery is indicated in various complications such as existence of persistent infections where bacteria survive, overextended root canal filling materials or paper points broken in periapical area during drying the root canals. In addition, the studies have shown that about 10% of the teeth indicating periapical infection are abutment teeth of a bridge or having other prothetic restorations such as crown and/or post. Particularly, in teeth having posts, orthograde endodontic therapy approaches may result in root fractures and tooth loss during removal of post from the canal system.

Pulp inflammation which occurs after cementation of multi-unit fixed prosthetic restorations also makes the retrograde endodontic therapy approach such as apical resection inevitable due to financial worries. The advantage of endodontic surgery intervention is that the apical part of the "problem tooth" is accessed fast, 3 mm of root end is cut, and retrofilled to 3 mm deep. So, root canal variations of apical part of 6 mm and therefore micro-organisms are removed. However, it should not be ignored that apical resection and retrograde filling can not remove all bacteria from the root canal system but only isolate them from periapical zone. In the article by Dr. Shimon Friedman published in the journal of "Endodontic Topics" in 2002, it is stated that the retrograde filling only isolates the bacteria in the root canal system; it fails to eliminate the microorganisms from the entire root canal.

Particularly, in long rooted teeth such as canine, considerably long canal space may remain between the retrograde filling and post restorations. In the studies it has been detected that the ratio of dentin canals in middle 1/3 of the roots is more when compared to apical 1/3, and in addition 10% of the roots have lateral canals in middle 1/3. This zone can be a good shelter for bacteria particularly in regard to persistent infection. Moreover, one of the most important purposes of the root canal therapy is the filling of the root canal system from coronal to apical fully and retrograde filling fails to achieve this target. Several approaches have been suggested in this regard respectively. First of them is to bend stainless steel canal file about 90° to shape the apical part by retrograde way. However, this method is time consuming and it may result in a focus of a new problem due to breaking of root canal instrument because of physical forcing. In the article by Dr. Shimon Friedman published in journal of "Endodontic Topics" in 2005, it was tried to shape the root canal terminal by bending root canal file 90°. However, this process takes long time and the instrument is at the risk of breaking. The shaping performed by a bended instrument cannot be effective. Moreover, the enlargement of bone cavity is needed in this method.

As a result, the need for retroshaping tubes eliminating the disadvantages available in the related art and inadequacy of existing solutions have necessitated development in the related art. Purpose of the Invention

From the current status of the related art, the purpose of the invention is to develop retroshaper tube functioning as guide in shaping root canals from apical to coronal during apical resection (cutting root end) procedure performed in dentistry and advance in the direction of coronal as desired in root canals not accessed through coronal (existence of post or zirconium crowns). By help of the rotary instruments made of Nickel-Titanium (Ni-Ti)₁ effectiveness of shaping in this area has been increased with tubes for retroshaping.

Another purpose of the invention is to provide easy access to apical part of the root by angular location of stainless steel tubes manufactured by casting technique. Thus, in cases where there is no periapical lesion, resection field can be smaller in size compared to the method applied by bended stainless steel files; and bone loss can be reduced to minimum level.

Ni-Ti instruments can also be used in this system. The fact that Ni-Ti alloy does not display plastic deformation even twisted at 90 degrees and that its good performance in fatigue studies supports this system.

Retroshaper tubes are casted by means of sensitive casting technology and will have a smooth inner structure. The instrument can also be manufactured of transparent or non-transparent hard plastic material for single use.

The invention does not constitute an obstacle for today's retrograde filling methods. After shaping and filling the canal from root apex, the retrograde cavity opening can be prepared by ultrasound tips as it is done in conventional methods and a retrograde filling material such as mineral trioxide aggregate can be placed.

In order to achieve the said purposes, a tube curved in a manner to form an α angle in order to provide direction for more effective use of canal instrument in small bone cavities during resection, which is located in apical of the tooth resected and guides positioning of the canal instrument in the canal has been developed. In a preferred embodiment of the invention the said α angle varies from 90° to 120°. In a preferred embodiment of the invention, the said tube is of cylindrical structure and made from stainless steel or transparent / non-transparent plastic material manufactured as cast.

In a preferred embodiment of the invention the said tube contains tube ends on both terminals.

The structural and characteristics features of the invention and all advantages will be understood better in detailed descriptions with the figures given below and with reference to the figures, and therefore, the assessment should be made taking into account the said figures and detailed explanations.

Brief Description of Figures

Figure -1- general perspective view of the said tube.

Reference Numbers

1. Tube

2. Tube end

3. Canal instrument

Detailed Description of the Invention

The invention relates to retro-shaper tube (1) functioning as a guide in shaping root canals from root apex towards coronal during apical resection procedure applied in dentistry and in root canals not accessed through coronal (such as existence of post or zirconia crowns). The said tube (1) is called "Retroshaper B-FR".

The retroshaper tube (1) displayed in perspective view in figure 1 consists of tubes (1) of inner diameter from 0,25 to 0,50 mm in a manner to increase 0,05 mm and is compatible with assortment canal instrument (3) system used between 15 - 40 size. Root canal instrument (3) with a taper of 2% (widens 0.02 mm in every 1 mm from apical to the handle), and preferably is manufactured without angle.

The said retroshaper tube (1) is of cylindrical structure and is twisted in a manner to form α angle. The said α angle varies between 90° and 120° and provides direction for more effective use of canal instrument (3) in small bone cavities during resection.

The said α angle may vary subject to convenience of apical of resected tooth. The long edge falling on upper side of the said α angle is 5 mm and the one on the lower part, the short degree after curvature is 2 mm long. The long edge is held by any holder such as a haemostat. The said retroshaper tube (1) contains tube ends (2) on both ends.

After apical resection (cutting end of the root), the tube (1) is located in apical of the root and is made stable by means of any holder. The said α angle is selected to the angle of root terminal. Then the canal instrument (3) (hand or rotary nickel titanium) is located in the canal by help of the tube (1) and shaping is performed. The purpose here is to apply the canal instrument (3) no matter how small the bone cavity is, by the help of the tube (1). It is very fast and safe when compared to shaping performed by curved hand instruments. Advancement up to the desired depth in coronal direction in retrograde shaping is a big advantage provided by retroshaper tube (1).

The said retroshaper tube (1) can be used with 2% tapered files (per each mm). These files can be nickel titanium hand or rotary instrument. However, files without taper, which is not widening from apical part towards the shaft(and handle) part can be manufactured and used with the system. When 2% tapered files are used, long edge of the tube (1) can be shortened in order to prevent blocking of the instrument. Shortening of short edge of the tube (1) can be provided and thus specific models can be developed.

The inner diameter of the said retroshaper tube (1) can be changed according to needs or rotary or hand file system to be used. Different tubes (1) can be modified according to the different files used for shaping during initial treatment or re- treatment. In addition, α angle can be changed and specific manufacturing as per anatomic zones can be provided. A special holder for the said retroshaper tube (1) can be developed and special areas can be produced around the tube (1) for this holder. The said tube (1) can be made of stainless steel in cast. Also it can be manufactured from transparent or non- transparent hard plastic. In addition to this system, filling set through which nickel titanium pluggers can also be applied. In this way injectable gutta-percha or retrograde filling materials can be condensed more effectively.

Concepts have been changing particularly in the journals published recently and views that root canal treatment can also be done from root apex have been suggested. It is because the materials used for the aesthetic expectations has gained more importance, and sometimes do not allow root canal treatment by means of coronal way. In addition, the idea of shaping the canal entirely after apical resection has been expressed more effectively. The said retroshaper tube (1) is a system which will enhance the effectiveness of file system in the canal to be used during shaping applied to meet these needs and can be easily sterilized.

The protection area of this application has been specified under claims and cannot be limited to the descriptions only given as sampling above. It is clear that any innovation can be provided by a person skilled in the related art by use of the similar embodiments and/or can also apply this embodiment in other areas for similar purposes used in the related art. Therefore, such embodiments will be lack of novelty criteria and particularly exceeding the related art.

Claims

1. A tube (1) curved in a manner to form an α angle in order to provide direction for more effective use of canal instrument (3) in small bone cavities during apical resection applied in dentistry (dental surgery) and shaping canals from root end towards coronal in root canals not allowing access through coronal and advancement up to the depth desired in coronal direction, which is located in resected tooth apical and guide location of canal instrument (3) through which it passes.

2. A tube (1) according to claim 1 and it is characterized in that the said α angle is between 90° and 120° as per specific areas.

3. A tube (1) according to claim 1 and it is characterized in that the said tube (1) is manufactured from stainless steel or plastic material of cylindrical structure.

4. A tube (1) according to claim 1 and it is characterized in that the said tube (1) contains tube ends (2) on both ends.