WO2006096900A1

WO2006096900A1 - Dental instrument

Info

Publication number: WO2006096900A1
Application number: PCT/AT2006/000114
Authority: WO
Inventors: Georg Watzek
Original assignee: Medizinische Universität Wien
Priority date: 2005-03-17
Filing date: 2006-03-17
Publication date: 2006-09-21
Also published as: AT506482A1

Abstract

The invention relates to a dental instrument for use, particularly, during percrestale sinus elevation, having a longitudinally extended, tubular-shaped base body, whereby the distal tube opening is closed by means of a covering made of an elastic, flexible material, which can be inflated in a balloon-like manner, when liquid is inserted into the base body. The invention is characterised in that the plastic membrane expands in a balloon-like manner when liquid is inserted therein, essentially forming an ellipsoid shape.

Description

DENTAL SURGERY INSTRUMENT

The present invention relates to a dental surgical instrument for use in a particular percrestalen sinus elevation, with an elongated, tubular base body, the distal tube opening is closed with a sheath made of an elastic, stretchable material that balloons when liquid is pressed into the tubular body becomes.

The upper jaw tooth area is an area of low bone supply in existing edentulous due to the increasing pneumatization of the antrum. This complicates the anchoring of dental implants for the purpose of dentures. It is therefore often not possible to use endosseous implants in this area without additional surgery.

As a rule, a pre-implantological increase in the existing bone supply has been carried out for years by the so-called sinus lift operation. This operation consists of a buccal-sided fenestration of the antrum, a denudation of the caudal cavity of the maxillary sinus, the alveolar recess, and insertion into the thus formed defect of autologous bone grafts or bone replacement materials. The maxillary sinus mucosa, which covers this area cranially, must remain intact.

As an alternative, the so-called percrestal sinus lift has been developed, but has in no way prevailed. In this technique, the alveolar ridge should be perforated from the oral cavity to the floor of the maxillary sinus. Ideally, the most cranial piece of bone, together with the maxillary sinus mucosa, should be lifted off the floor of the maxillary sinus using appropriate stuffing devices. The filling of the resulting, through the maxillary sinus mucosa after cranial to always covered cavity should then be done by the alveolar ridge perforating tube. The diameter of this tube is in the rule about 3 mm, in particular 2-3 mm. If the sinus lift operation has been successful, the implants can be used several months later.

The advantage of the percrestal sinus lift is that it represents a minimally invasive procedure. In this technique, however, there is a great risk that the maxillary sinus mucosa is torn or perforated. In the case of a perforation, the filling material to be replenished would be distributed throughout the remaining maxillary sinus. Another disadvantage is that the percrestal sinus lift is not feasible to a greater extent with the existing equipment.

The classic sinus lift operation of buccal has as a disadvantage first the fact of a surgical procedure with all risks, as well as the most careful preparation the risk of perforation of the maxillary sinus mucosa. According to literature, this risk is between 10% and 30%.

In the prior art, a dental surgical instrument of the type mentioned is known ("Subantral Membrane Elevator (SME)" Manufacturer: Osseous Technologies of America, USA) .This instrument is a kind of catheter, on the distal end of a shell of a stretchable, This catheter is inserted into the canal as far as the jaw mucous membrane, after which fluid is injected into the catheter causing the sheath to inflate in a balloon-like manner the maxillary sinus.

Experiments on the anatomical specimen have shown, however, that this method is insufficient, since it nevertheless comes in the vast majority of cases to tearing the maxillary sinus mucosa. This is where the invention, which sets itself the task of providing a dental surgical instrument for use in a particular percrestal sinus elevation, in which the risk of perforation of the maxillary sinus mucosa is minimized.

To solve the problem, a dental surgical instrument is proposed, which has an elongated, tubular body, the distal tube opening is closed with a sheath made of an elastic, stretchable material that inflates like a balloon when liquid is pressed into the tubular body and characterized is that the shell is such that the forming during the injection of liquid balloon-like inflation essentially assumes the geometry of an ellipsoid.

The invention is based on the recognition that the risk of perforation emanates from the spherical inflation of the envelope and that this danger can be minimized, the more this distension goes from the spherical shape and becomes an ellipsoid. It has been found that the inflation of the elastic sheath in an ellipsoidal shape a lot more gentle lifting of the maxillary sinus mucosa and significantly reduces the risk of perforation.

The shell then assumes a shape deviating from the spherical shape when inflated, if it has different elastic elongation properties. This known fact is e.g. has long been exploited in the production of balloon figures. The different elongation properties can be achieved, for example, by choosing different material compositions or else by different thicknesses of the same material (for example DE 203 09 386 U1).

The envelope is thus an elastically extensible material, e.g. Rubber, rubber or an elastomeric plastic, e.g. also silicone, which of course must be compatible with the body. Such materials have long been used in the manufacture of balloon and urine catheters.

A preferred embodiment of the inventive dental surgical instrument is characterized in that the short axis of the ellipsoid is at most 4 mm and the long axis of the ellipsoid is a maximum of 20 mm.

The volume of the ellipsoid is preferably at most 3 ml, in particular at most 1 ml.

A further preferred embodiment of the dental surgical instrument according to the invention consists in that it has a filling device for injecting liquid into the tubular base body or a connection for a filling device at the proximal end of the tubular body.

Another embodiment of the dental surgical instrument according to the invention is characterized in that it has at the distal end an introducer sheath with a cavity from which the ellipsoidal balloon is deployed.

With the drawing preferred embodiments of the dental surgical instrument according to the invention are explained in detail.

In the figure 1 is denoted by the reference numeral 1 of the elongated tubular body, which is preferably made of metal. This main body 1 is closed at its distal end with the inflatable casing 2. This can be accomplished by, for example, pulling a suitably shaped plastic membrane over the pipe end and is attached by means of a ring 4 made of elastic Kunsstoff on the Grandkörper and sealed accordingly.

On the base body 1, a flexible hose 5 is attached, the end of a Luer connector 6 has. At this connector 6, e.g. a syringe and liquid are pressed. In this case, the inflatable casing 2 expands and forms the ellipsoid 3, which is shown in dashed lines in the figure.

Fig. 2 also shows an embodiment of the dental surgical instrument according to the invention, in particular for use in a percrestal sinus elevation, with an elongated tubular body 7. The distal end of the tube of this instrument is by an insertion 11 on which a balloon 10, the sheath of a elastic, stretchable material is made, mounted, formed and at the same time serves to seal the pipe end. The proximal edge of the insertion tube 11 is closed by a spacer or adjusting ring 12, which serves as a stop when inserting the instrument in the drilled alveolar channel. The proximal end of the tube 7 is formed by a Luer-Lock connector 8 directly or via a flexible tube, which serves to connect a syringe 9, with which liquid can be injected to inflate the balloon. In addition to standard syringes, a syringe with a graduated delivery of the volume and a pulsation unit can be used, through which the balloon can be inflated gradually and in a controlled manner with liquid (NaCl, higher viscous liquid), up to a diameter of up to 20mm and one of the molds corresponding height. The ellipsoid reaches a standard filling volume of approx. 3ml.

The use of the instrument for percrestal sinus lift is performed as schematically illustrated with reference to Fig. 3 (Figs. 3a-3c). First, the alveolar canal in the jawbone 13 (FIG. 3 a) is drilled with a cannon drill until approximately 1 mm before reaching the Schneiderian membrane 14. The last bony part can then be buffed with an osteotome. Alternatively, there is also the possibility of removing this piece of bone also by means of special bone milling methods (for example piezoelectric or ultrasound). These steps correspond to the procedures already used in the clinic.

The instrument is inserted so that the Schneiderian membrane is raised about 3mm. The adjusting ring, which rests on gum 15 after insertion, serves as a stop aid and, with the appropriate setting (bone height + 3 mm), ensures that the membrane is raised correctly and the balloon is free for lateral expansion. As the balloon inflates, it expands differently along its coordinate axes and assumes the shape of an ellipsoid (ellipsoid of revolution, ellipsoid). Due to this particular expansion behavior of the balloon, the lifting of the jaw mucous membrane is not formed exclusively by a tensile force along the sensitive Schneiderian membrane but rather by a scraping force on the outer circumferential surface of the lenticular balloon.

In addition to the principal method of bloating, another point was shown in the implementation and use of the balloon.

In order to obtain the desired shape and to permit the lateral expansion of the balloon it is necessary in the first phase to slightly lift the pine mucosa to form a first space and to inflate as a result of the balloon as already described. The lifting can be done in two ways.

When using an ellipsoidal balloon with an introducer sheath (corresponding to the simplest basic shape of the sinus lift balloon), the surgeon's jaw is lifted by gentle pressure on the mucosa as previously described, with an adjustable depth stop preventing perforation due to over penetration. In combination with a corresponding introducer sheath with cavity 16 (FIG. 4a), in which a pressureless and folded balloon 17 is inserted, the lifting of the pine mucosa takes place in the early phase of the pressure build-up. Here, by the pressure increase of the balloon, which is folded in the introducer sheath, driven out of the sleeve along its axis (Fig. 4b). When the balloon exits, this results in the first lifting of the mucous membrane. Upon further pressure increase, the balloon escapes completely from its rigid shell and can then take its actual starting shape, which corresponds to the relieved balloon shape (mold), take (Figure 4c) and continue to expand in this form (Figure 4d). In this method, the first pressure on the mucous membrane can be applied in a controlled manner and a more favorable geometry (casting mold) and a greater choice of materials can be selected in the production of the balloon.

To inflate the balloon, a syringe may be used with NaCl or a more viscous liquid than water, the advantage being the slower actuation of the syringe and thus the balloon being more gently dilated. The gentle expansion of the balloon can also be realized by means of a syringe with a stepped metering option and pulsation unit, which is suitable for this purpose, as shown in FIG become. Thus, the abrupt application of pressure, which is reflected in a stress load of the membrane, avoided and lifted the membrane accordingly carefully.

The syringe shown in Fig. 5 consists of a syringe body 18, in which a nose 19 is integrated for a feed screw 20. By turning the Zustellring 21 of the syringe die 22 is moved forward and pressed the liquid in the syringe into the balloon. The pitch of the feed screw 20 is not continuous, but interrupted again and again in such a way that in a full revolution of the feed screw of the punch is moved in the first half turn by a small stroke and in the second half turn the punch is stationary. This ensures that only a small amount of liquid per revolution is pressed and the balloon expands in several stages. By this interrupted stretching with breaks one achieves a gentle lifting of the pine mucous membrane with subsequent endurance pauses. Likewise, the pressure can be controlled better with slow deliveries in this method than with the usual syringes. In addition to these stages, smaller pressure pulses may be delivered by pressing the pulse button 23. This pulse button 23 is connected via an integrated in the syringe plunger 22 axis 24 with the movable extrusion plate 25. By pressing the Pulsknopfe, which is placed on the spring 26 when discharging in its rest position, moving the Auspressplatte minimal forward, whereby small pressure pulses are generated until the membrane continues to stand out. This also gives feedback on the condition of the balloon and the membrane.

Claims

CLAIMS:

A dental surgical instrument for use in a particular percrestal sinus elevation, comprising an elongated, tubular base body (1) whose distal tube opening is closed by an inflatable sheath (2) made of an elastic, stretchable material which expands like a balloon when liquid in the tubular base body (1) is pressed,

characterized in that

the shell is such that the balloon-like expansion which forms during the injection of liquid essentially has the geometry of an ellipsoid (3).

2. Dental surgical instrument according to claim 1, characterized in that the short axis of the ellipsoid (3) is at most 4 mm and the long axis of the ellipsoid maximum 20 mm.

3. Dental surgical instrument according to one of claims 1 or 2, characterized in that the volume of the ellipsoid (3) is a maximum of 3 ml, in particular a maximum of 1 ml.

4. Dental surgical instrument according to one of claims 1 to 3, characterized in that it is at the proximal end of rohrfömigen base body (1) a filling device (5; 6) for injecting liquid into the tubular body or a connection (6) for a filling device having.

5. Dental surgical instrument according to one of claims 1 to 3, characterized in that it has at the distal end an introducer sheath (11) with a cavity (16) from which the ellipsoidal balloon unfolds.