WO2025193203A1

WO2025193203A1 - NICKEL-TITANIUM (Ni-Ti) FILE

Info

Publication number: WO2025193203A1
Application number: PCT/TR2025/050208
Authority: WO
Inventors: Emre ÖVSAY
Original assignee: Shangai Fanta Dental Materials Co Ltd
Current assignee: Shangai Fanta Dental Materials Co Ltd
Priority date: 2024-03-14
Filing date: 2025-03-05
Publication date: 2025-09-18
Anticipated expiration: 2026-09-14
Also published as: TR2024003087A2

Abstract

The invention relates to a nickel -titanium (Ni-Ti) file used in all fields of dentistry, including root canal treatment (endodontic applications), and in patient treatment processes related to root canal therapy. The Ni-Ti file is designed to remove filling residues, dental pulp, and other residual materials from within the root canal during endodontic procedures.

Description

Nickel-Titanium (Ni-Ti) File

Technical Field

The invention relates to a nickel -titanium (Ni-Ti) file used in all fields of dentistry, including root canal treatment (endodontic applications) and patient treatment processes associated with root canal therapy.

Specifically, the invention pertains to a nickel -titanium (Ni-Ti) file designed for the removal of filling residues, dental pulp, and other residual materials from within the root canal during endodontic treatment.

State of the Art

Root canal treatment involves the removal of the coronal and root pulp, mechanical shaping of the root canal cavity, disinfection of the canal, and hermetic filling of the canal from the coronal access cavity to the apical foramen. One of the most critical factors affecting the success of root canal treatment is the mechanical shaping of the root canals. Shaping is performed using various root canal instruments to remove vital, necrotic tissues and infected dentin from the root canal, ensuring optimal filling by giving the canal a properly tapered form that expands from apical to coronal. This process removes bacterial biofilm and provides an appropriate space for antimicrobial irrigation solutions and medications to exert their effects and disinfect the root canals.

Before modern dentistry, instruments used for trephination (likely meaning preparation) of teeth were employed to prepare root canals and cauterize the pulp. For many years, root canal preparation was performed using stainless steel files and reamers. However, shaping the root canals using these instruments has been associated with several complications. Particularly, shaping narrow and curved canals is time-consuming and challenging. Additionally, during the shaping process, errors such as transportation, apical zip formation, ledge formation, step creation, perforations, loss of working length due to canal blockage, canal straightening, and instrument fractures may occur.

In current root canal treatment techniques, difficulties arise in creating an apical stop. When the master cone (GP) extends beyond the apical region, postoperative sensitivity and certain complications may occur. Therefore, there is a need to prevent potential complications that may arise during the establishment of an apical stop or canal length calculation.

A review of the literature identifies EP4023186B1 as an example of the state of the art. This document pertains to an endodontic file used for dental nerve treatment. The file described is essentially a spiral-shaped blade designed to be placed in the root canal to remove the dental nerve and widen the canal, a head that is detachably mounted on a rotary electric device, and a connecting section extending at a predetermined length between the head and the blade, with a diameter smaller than that of the contact ends of both the blade and the head. The purpose of the thin connecting section is to concentrate stress during rotation on the connector instead of the blade. However, this invention does not mention any improvements aimed at preventing complications that may arise during apical stop formation or canal length calculation.

As a result, the presence of these problems and the insufficiency of existing solutions have necessitated an improvement in this technical field.

Objective of the Invention

The present invention relates to a nickel -titanium (Ni-Ti) file that eliminates the aforementioned disadvantages and introduces new advantages to the relevant technical field.

The primary objective of the invention is to provide a nickel -titanium (Ni-Ti) file that facilitates the removal of filling residues, dental pulp, and other residual materials from the root canal during endodontic treatment.

Another objective of the invention is to provide a nickel -titanium (Ni-Ti) file that ensures sufficient tug-back (gutta-percha adaptation during canal filling) in the apical region.

Another objective of the invention is to provide a nickel -titanium (Ni-Ti) file that enables the transportation of debris out of the canal during shaping.

Another objective of the invention is to provide a nickel -titanium (Ni-Ti) file with a significantly more effective cutting efficiency, debris removal compared to existing systems.

Another objective of the invention is to provide a nickel -titanium (Ni-Ti) file that preserves the internal form of the root canal for anatomical shaping, making it suitable for the root canal structure and anatomical applications.

Another objective of the invention is to provide a nickel -titanium (Ni-Ti) file with a fixed taper and a variable taper, enabling controlled shaping within the canal while preventing excessive taper increase.

To achieve the objectives mentioned above and others derived from the detailed description, the invention comprises a nickel -titanium (Ni-Ti) file used in all fields of dentistry, including root canal treatment (endodontic applications) and patient treatment processes related to root canal therapy. The file is characterized by:

• A shaft (20) made of nickel -titanium wire with a grooved structure, spirally extending downward from the lower part of the head (10), designed to remove diseased (infected) dental nerves from the patient’s root canal,

• A coronal part (21) forming the upper section of the shaft (20), with a square or quadrangular cross-section, enabling coronal shaping and debris transportation, • A middle part (22) forming the middle section of the shaft (20), with a modified quadrangular cross-section, designed for debris removal from the root canal and anatomical shaping with a fixed and variable taper,

• An apical part (23) forming the lower section of the shaft (20), with a triangular cross-section, convex triangular cross-section, or circular cross-section, enabling progression in calcified canals, debris transportation, formation of the apical stop, and creation of tug-back without shaping the apical region. (without interfering the apical morphology)

The structural and characteristic features of the invention, along with all its advantages, will be better understood with reference to the following figures and the detailed explanations associated with them. Therefore, the evaluation should consider these figures and the accompanying detailed description.

Figures for Better Understanding of the Invention

Figure la: View of the nickel -titanium (Ni-Ti) file of the invention.

Figure lb: Alternative configuration of the nickel -titanium (Ni-Ti) file.

Figure 1c: Alternative configuration of the nickel -titanium (Ni-Ti) file.

Figure Id: Alternative configuration of the nickel -titanium (Ni-Ti) file.

Figure le: Alternative configuration of the nickel -titanium (Ni-Ti) file.

Explanation of Reference Numbers

10: Head

20: Shaft

21: Coronal part

22: Middle part

23: Apical part a: Thread pitch distance a: Taper angle

DETAILED DESCRIPTION OF THE INVENTION In this detailed description, the preferred alternatives of the nickel -titanium (Ni-Ti) file subject to the invention are explained solely for better understanding of the subject and without imposing any restrictive effects.

Figures la, lb, 1c, Id, and le illustrate the nickel -titanium (Ni-Ti) file of the invention. Accordingly, in its most basic form, the nickel -titanium (Ni-Ti) file comprises a head (10) mounted on a rotary electric device, and a shaft (20) made of nickel -titanium wire with a grooved structure, spirally extending downward from the lower part of the head (10), designed to remove diseased dental nerves from the patient’s root canal.

The nickel -titanium (Ni-Ti) file subject to the invention consists of a shaft (20) with a grooved structure that extends spirally downward from the head (10). The shaft (20) is divided into three sections, each with different cross-sectional structures:

• The coronal part (21), forming the upper section,

• The middle part (22), forming the middle section,

• The apical part (23), forming the lower section.

Structural Variations of the Shaft

As seen in Figure la, the coronal part (21), middle part (22), and apical part (23) of the shaft (20) may have a convex triangular cross-section. The taper angle (a) of the shaft (20) in Figure la can be 9.5° or 10.5°.

The thread pitch distances (a) in a 9.5° taper angle (a) configuration are as follows:

• Coronal part (21) thread pitch distance (a): 1.145 mm

• Middle part (22) thread pitch distance (a): between 0.685 mm and 1.350 mm

• Apical part (23) thread pitch distance (a): between 0.21 mm and 0.590 mm

The thread pitch distances (a) in a 10.5° taper angle (a) configuration are as follows:

• Coronal part (21) thread pitch distance (a): 1.545 mm

• Middle part (22) thread pitch distance (a): between 0.705 mm and 1.440 mm

• Apical part (23) thread pitch distance (a): between 0.180 mm and 0.600 mm

Alternative Configurations of the Shaft

• As shown in Figure lb, the coronal part (21) of the shaft (20) may have a square crosssection. This square cross-section enables coronal shaping and debris transportation. The middle part (22) may have a quadrangular cross-section, which facilitates debris removal from the root canal and anatomical shaping with a fixed taper. The apical part (23) may have a triangular cross-section, which enables advancement in calcified canals, debris transportation, and the formation of an apical stop. The taper angle (a) in Figure lb can be 3.2°.

The thread pitch distances (a) in a 3.2° taper angle (a) configuration are as follows:

• Coronal part (21) thread pitch distance (a): between 0.556 mm and 0.652 mm

• Middle part (22) thread pitch distance (a): between 0.300 mm and 0.524 mm

• Apical part (23) thread pitch distance (a): between 0.140 mm and 0.268 mm

• As shown in Figure 1c, the coronal part (21) of the shaft (20) may have a square crosssection, while the middle part (22) may have a quadrangular cross-section. The apical part (23) may have a convex triangular cross-section, which facilitates advancement in calcified canals, debris transportation, and apical stop formation. The taper angle (a) in Figure 1c can be 3.8°.

The thread pitch distances (a) in a 3.8° taper angle (a) configuration are as follows:

• Coronal part (21) thread pitch distance (a): between 0.694 mm and 0.808 mm

• Middle part (22) thread pitch distance (a): between 0.390 mm and 0.656 mm

• Apical part (23) thread pitch distance (a): between 0.200 mm and 0.352 mm

• As shown in Figure Id, both the coronal part (21) and the middle part (22) of the shaft (20) may have a quadrangular cross-section, while the apical part (23) may have a convex triangular cross-section. This configuration enables advancement in calcified canals, debris transportation, and the formation of an apical stop. The taper angle (a) in Figure Id can be 4.2°.

The thread pitch distances (a) in a 4.2° taper angle (a) configuration are as follows:

• Coronal part (21) thread pitch distance (a): between 0.800 mm and 0.926 mm

• Middle part (22) thread pitch distance (a): between 0.464 mm and 0.758 mm

• Apical part (23) thread pitch distance (a): between 0.254 mm and 0.422 mm

• As shown in Figure le, the coronal part (21) and the middle part (22) of the shaft (20) may have a quadrangular cross-section, while the apical part (23) may have a circular crosssection. This configuration ensures the formation of an apical stop while enabling tug-back without shaping the apical region. The taper angle (a) in Figure le can be 4.4°. The thread pitch distances (a) in a 4.4° taper angle (a) configuration are as follows:

• Coronal part (21) thread pitch distance (a): between 0.725 mm and 0.989 mm

• Middle part (22) thread pitch distance (a): between 0.464 mm and 0.813 mm

• Apical part (23) thread pitch distance (a): between 0.285 mm and 0.422 mm

Claims

1. A nickel -titanium (Ni-Ti) file used in root canal treatment (endodontic applications) across all fields of dentistry, including patient treatment processes related to root canal therapy, comprising a head (10) placed on a rotary electric device, characterized by: • A shaft (20) made of nickel -titanium wire with a grooved structure, extending spirally downward from the lower part of the head (10), designed to remove diseased dental nerves from the patient’s root canal,

• A coronal part (21) forming the upper section of the shaft (20), with a convex triangular cross-section, square cross-section, or quadrangular cross-section, enabling coronal shaping and debris transportation,

• A middle part (22) forming the middle section of the shaft (20), with a convex triangular cross-section or quadrangular cross-section, designed for debris removal from the root canal and anatomical shaping with a fixed and variable taper,

• An apical part (23) forming the lower section of the shaft (20), with a triangular cross- section, convex triangular cross-section, or circular cross-section, enabling progression in calcified canals, debris transportation, formation of the apical stop, and creation of tug-back without shaping the apical region.