CA1220369A

CA1220369A - Self-adapting retentive endodontic build-up post

Info

Publication number: CA1220369A
Application number: CA000470769A
Authority: CA
Inventors: Hans-Werner Weisskircher
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-12-21
Filing date: 1984-12-21
Publication date: 1987-04-14

Abstract

ABSTRACT

1. SELF-ADAPTING RETENTIVE ENDODONTIC BUILDUP-POST.
Core buildups of endodontically treated teeth the crowns of which are fractured, weakened, or destroyed by caries can be done in basically 2 ways:
- cast post and core - prefabricated posts with metal cores or cores in combination with acrylics.
Retention is achieved through cementation, threads on the post, or a combination of the two. In order to achieve the best possible hold and to prevent stress of surrounding tissue, most prefabricated post systems re-quire preliminary precision drilling. Due to the use of these cylindrical posts, two problems often occur.
First of all, in teeth which have tapered canals or slender roots, perforation of the canal wall can occur.
Secondly, in teeth with very large or very asymmetrical canal lumen, sufficient actual retention can be very difficult to achieve. Although the treatment of choice in such cases is the cast post, in comparison to the pre-fabricated post it is work and time consuming.
The objective for my invention was the development of a pre-fabricated endodontic post that is simple and time saving, and can also be used in flaring or very oval canals without comprising the clinical strength or stability necessary for the core build-up. I have named this the self-adapting retentive endodontic build-up post, hereafter called the S.A.R. Post.

Description

I Jo a SPECIFICATION

My invention consists of a prefabricated metal pin to be used to stabilize and reinforce the root canal filling and -the core build-up in -the treatment of teeth with deeply caries-damaged or fractured crowns. The pin is to be made of wire characterized by corrosion resistance, bio-compati-ability and high elasticity.
The features of this post which distinguish it from all other endodontics post and anchor systems available on -the market are its very uncomplicated implementation and, more importantly, its utilization of the entire opened root canal cross-section. This is especially advantageous where the canal lumen is very large, very asymmetrical, or oval. AS this system I does not require the precise redrilling necessary with other systems, the treatment time is shortened considerably, resulting in savings for the dentist and the potent.
This system takes advantage of the properties of modern dental materials such as acrylics and composites which have high compression and tensile strength, which together with newly developed dentin adhesives can to a certain degree adhere to clean dentin surfaces.
The novelty of my device is that the great retention of the post is achieved through flexible radiating lamely which, immediately on insertion, due to their elasticity and arrangement independently adapt themselves to, and wedge into I

the dentin walls.
Redrilling which in small canals or slender roots can result in perforation of the canal wall or a root free-lure is not necessary with this post. The post is inserted with the same filling material (such as acrylic or composite) with which the core build-up will be done. Thus, the same post which reinforces the root canal filling also reinforces the core build-up. This results in a unified system of root canal filling and core build-up with clinically significant resistance to torsional, tensile, shearing and compressive forces, without the great rigidity of other systems which can often oversteers the surrounding tooth structure.
The SYRIA. Post is to be manufactured in different forms, lengths, and diameters.

I

PROCEDURE

Following are the procedural working steps utilizing the SYRIA. Post, up to the stage of the core build-up:

(1) instrumentation of the canal using standard methods, to lam from the radiographic apex of the canal, to at least file No. 25 (Is size).

(2) after irrigation and drying of the canal, sealing of the apex by application of a bio-compatible, fast hardening root canal cement. Radiographic check.

(3) leaving a 2-5 mm seal, depending on length of the root and special curvatures, further instrumentation to file No. 35.

(4) final instrumentation using the 'step-back' technique to at least file No. 50, in the case of asymmetric canals achieving an oval lumen cross-section

(5) selection of type and size of SYRIA. Post to be used and, if necessary, shortening of the post at its apical end.

(6) cleaning of the canal with citric acid, Nikolai or ETA
and drying of the canal.

(7) application of a den-tin adhesive to canal walls.

(8) introduction of acrylic or composite filling material to the canal as well as coating the entire SYRIA. Post with the same material.

(9) Insertion of the S.A.R.Post with adequate pressure until resistance if felt and then immediately releasing the post to allow the retention lamely to wedge into the dentin walls.

(10) After curing of the filling material, removal of the finger-trip and completion of the core build-up as usual.

Fig. 1. - shows a side view.
Fig. aback, -show views of the cross-sections at three different levels.
Foe- - shows a to view of the post.

)369 DESCRIPTION OF THE DRAWINGS

Fig. #l - shows the SYRIA. Post in full length, with the part with the radiating lamely drawn to represent a cross-section of 120.
100 (See angle indicated on Fig. 3).
In this drawing the central pin is conical, in another version it would be cylindrical. In both cases the pin tapers from the most apical lamely to the tip. The lengths of the pins correspond to the commonly used files.
(Standard Is sized files.
The finger grip is a solid, cylindrical continuation of the central pin, with beveled edges and the sun-face is crosshatched for better grip. Directly 110 under the finger grip is a break point by way of a milled Cult to facilitate its removal after insertion The left side of Fig. 1 (a) shows -the lamely be-coming shorter apical. The right side (b) shows the lamely which are at 120 to the ones drawn on side (a)- These lamely are of the same length to a certain point on the pin, apical to which they also become gradually shorter.
Fig. I - (a), (b), and (c) show the horizontal cross-sections representing different points in the length of the 120 post as it is drawn in Fig. I

I pi fiL/~d2~J3~

ig. I - shows a top view of -the coronal end of the finger grip. Also shown is the angle represented by the left (a) and right + (b) sides of Figure 1.

The Inventor reserves claim to his patent rights for the SYRIA. Post in the case of minor alterations such as to size, length, form and number of lamely that it may be subjected to.

Claims

The embodiments of the invention in which an exclusive property privilege is claimed is defined as follows:

(1) A metal endodontic post, tapered, or non-tapered, for the retention and reinforcement of acrylic or compo-site core build-ups of damaged, fractured or weakened non-vital teeth, with flexible laterally radiating lamellae which can adapt themselves to the walls of the root canal, and wedge into the walls thereby achieving a high level of retention.
(2) A metal endodontic post as defined in claim (1) which at its apical end tapers into a pin corresponding to standard dental Iso sizes, which due to its flexibility can follow crooked or bent root canals.
(3) metal endodontic post as defined in claims (1) and (2) having a cross-hatched solid head to function as a finger grip, with a break point milled in under the head.