Field of application of the invention

The present invention is applied in the field of instruments and devices which can be used by a dental practitioner during a diagnostic or therapeutic treatment of the mouth or teeth.

More precisely, the present invention relates to a cap for saliva ejector provided with means which prevent the obstruction thereof by the oral mucosa. The invention further relates to a saliva ejector comprising such a cap.

Prior art overview

A saliva ejector is an instrument commonly used by a dental practitioner during a diagnostic or therapeutic treatment of the mouth or teeth in order to remove accumulations of saliva possibly formed inside the oral cavity during the treatment.

Saliva ejectors generally comprise a bending cannula connected to an aspirator at a first end and closed by a perforated cap at a second end opposite the first end. At the perforated cap, the saliva ejector is placed into the mouth, preferably near the oral floor. The mucosa forming the oral floor is however flaccid. As a result, it often happens that the depression created by the saliva ejector in the oral cavity raises the aforementioned mucosa to the point that it contacts the cap, thus obstructing it. This causes discomfort both to the patient, who feels a sense of discomfort at the oral floor, and to the dentist who, if not assisted by a hygienist, in order to avoid the formation of saliva accumulations must interrupt the treatment he is doing and detach the saliva ejector from the oral mucosa of the patient.

In order to try to prevent the aforesaid drawback, the cap of a saliva ejector usually has an elongated, almost cylindrical shape, with through holes present both on the top portion of the cap and on the lateral wall thereof. Since the holes are also distributed on the lateral wall of the cap, the suction surface of the latter is three-dimensional (unlike the two-dimensional cannula inlet mouth). In the case of obstruction of the cap at the top portion, the suction can therefore continue at the lateral wall thereof.

However, the area of the suction surface of the cap is greater than the area of the cannula inlet mouth. At the same air inlet flow rate in the aspirator, the depression at the holes in the cap is therefore lower than the depression at the inlet mouth of the cannula. The force exerted by the aspirator on the oral mucosa is thus lower.

Furthermore, although the use of an elongated perforated cap reduces the risk of the saliva ejector being obstructed by the oral mucosa, the above problem continues to occur, especially in patients with an extremely flaccid oral floor. Object of the invention

It is the object of the present invention to overcome the aforementioned drawbacks by providing a cap for saliva ejectors provided with means which prevent an obstruction thereof by the oral mucosa.

Summary of the invention

The present invention relates to a cap for saliva ejector comprising:

· at least one lateral wall interposed between a first and a second base which are mutually opposed;

• a plurality of through holes formed at the lateral wall and the first base to allow the saliva to enter the cap;

• an opening formed at the second base to allow a connection between the cap and a cannula of a saliva ejector, so as to allow the saliva possibly present inside the cap to enter the cannula,

where, according to the invention, the cap comprises: • a plurality of spacer means transversely protruding from the lateral wall and above the first base.

Advantageously, when the cap of the invention, fitted on a cannula of a saliva ejector, is placed inside a patient's mouth, the spacer means prevent the oral mucosa from contacting the first base and the lateral wall of the cap, thus preventing obstruction of the through holes by said mucosa.

The invention also relates to a saliva ejector comprising:

• a cannula;

• a cap comprising:

- at least one lateral wall interposed between a first and a second base which are mutually opposed;

- a plurality of through holes obtained at the lateral wall and at the first base;

- an opening made at the second base for reversibly connecting the cap to the cannula,

where, according to the invention, the cap comprises:

- a plurality of spacer means transversely protruding from the lateral wall and above the first base.

Incidentally, the adverb "reversibly" means that the cap is disconnectable from the cannula.

Other innovative features of the present invention are disclosed in the following description and referred to in the dependent claims.

Brief description of the drawings

Further objects and advantages of the present invention will become apparent from the following detailed description of an exemplary embodiment thereof and from the accompanying drawings, which are merely illustrative and non-limiting, in which:

- figure 1 shows a perspective view of a cap for saliva ejector according to the present invention;

- figure 2 shows a top plan view of the cap in figure 1 ;

- figure 3 shows the cap in figure 1 rotated by 30° about the longitudinal axis thereof;

- figure 4 shows a saliva ejector comprising the cap in figure 1 . Detailed description of some preferred embodiments of the invention

Hereinafter in the present description, a figure may also be shown with reference to elements not expressly indicated in that figure but in other figures. The scale and proportions of the various elements depicted do not necessarily correspond to the actual ones.

Figures 1 to 3 show a cap 1 , according to the invention, of the type "for saliva ejector", that is, a cap connectable to the free end of a cannula suitable for suctioning saliva accumulations which may form in a patient's mouth during a dental treatment.

Cap 1 comprises at least one lateral wall 2 interposed between a first base 3 and a second base 4 which are mutually opposed. The wall 2 is preferably frustoconical in shape, with its own generatrixes preferably inclined by a few degrees with respect to a longitudinal axis 5 thereof (arranged perpendicular to the base 4). Said low inclination causes the wall 2 to appear almost cylindrical in shape. The bases 3 and 4 are preferably circular and arranged orthogonally to the axis 5. Due to the frustoconical shape of the wall 2, the base 3, top in figures 1 and 3, has a width slightly lower than that of base 4. The outer surface of the base 3 is preferably convex at a peripheral portion 6 where it is joined to the wall 2. The cap 1 therefore appears rounded at the junction between the wall 2 and the base 3.

The cap 1 has a plurality of through holes 7 and 8 made at the base 3 and a portion of the wall 2 adjacent thereto. More precisely, the cap 1 comprises, at the base 3, a through hole 7 (figure 2) preferably circular and more preferably concentric to said base 3. From hole 7, other through holes 8 branch off, shaped as grooves, which cross the preferably radially base 3 and continue longitudinally in the wall 2 over a portion thereof adjacent to base 3. The grooves 8 are preferably present in a number equal to six.

The cap 1 , at the base 4, comprises a large opening 9 (visible in figure 3) preferably circular and more preferably concentric to said base 4. Through the opening 9, the cap 1 is connectable to a cannula of a saliva ejector. More precisely, through the opening 9, the cap 1 (figure 4) can be fitted on a cannula so as to provide a connection by interlocking therewith. When the cap 1 is connected to a cannula of a saliva ejector and is inserted into a patient's mouth, the hole 7 and the grooves 8 allow saliva to enter the cap 1 and the opening 9 allows the passage of said saliva from the cap 1 to the aforementioned cannula. In order to strengthen the connection between a cannula of a saliva ejector and the cap 1 , the latter comprises a plurality of incisions 10 (visible in figure 3), preferably circular, made at the inner face of the wall 2, in the portion of the latter not crossed by grooves 8. The incisions 10 are preferably mutually parallel, more preferably parallel to the base 4 and even more preferably concentric thereto.

The cap 1 further comprises a ring 1 1 connected to the wall 2 inside the latter, below hole 7. The ring 1 1 is preferably parallel to the base 3 and more preferably concentric to the base.

In light of the foregoing, the cap 1 is preferably symmetrical with respect to the axis 5.

The cap 1 is preferably made of polymeric material, and more preferably polyvinyl chloride (also known as PVC). Regarding the dimensions, the wall 2 has a height preferably of 15 mm, the base 3 has an outer diameter preferably of 8 mm, the base 4 has an outer diameter preferably of 9.4 mm and the hole 7 has a diameter preferably of 3 mm. The grooves 8 have a width of preferably 1 .5 mm and extend over a stretch of wall 2 (top in figures 1 and 3) by a length preferably comprised between one third and half of the height of the wall 2. The opening 9 has a diameter of preferably 7.8 mm. The ring 1 1 has an inner diameter preferably of 1 .5 mm, an outer diameter preferably of 3.4 mm, and a thickness preferably of 0.7 mm.

The features of cap 1 described thus far are known. Therefore, further details are not provided.

What distinguishes cap 1 from known caps for saliva ejectors is the presence of a plurality of elements 20 extended in length and, taken as a whole, projecting from cap 1 transversely to wall 2 and above base 3. The elements 20 are preferably shaped as short spines connected to the wall 2 and/or to the base 3 at a first end 21 . The elements 20 are preferably straight, have a preferably circular cross-section and are preferably beveled at a second end 22 opposite the end 21 .

Advantageously, when the cap 1 , connected to a cannula of a saliva ejector, is placed into a patient's mouth, the elements 20 act as spacer means of the patient's oral mucosa from the wall 2 and from the base 3, so as to prevent said mucosa from contacting them. Therefore, the elements 20 prevent obstruction of the hole 7 and of the grooves 8. Advantageously, due to the fact that the end 22 is beveled, when the elements 20 contact the oral mucosa of a patient, they do not cause pain or discomfort to the latter.

As can be seen in figures 1 and 3, some of the elements 20 (indicated hereinafter also with the reference numeral 20A) are preferably connected to the wall 2, other elements 20 (indicated hereinafter also with the reference numeral 20B) are preferably connected to the base 3, more preferably at the peripheral portion 6 thereof. The elements 20A protrude transversely from the wall 2. The elements 20B protrude from the portion 6 both transversely to the wall 2, and above the base 3. As a whole, therefore, as mentioned above, the elements 20 act as spacer means protruding transversely to the wall 2 and above the base 3.

Advantageously, this preferred arrangement of the elements 20 is such as to minimize the risk that the hole 7 and the grooves 8 can be obstructed by the oral mucosa of a patient. The elements 20A, in fact, keep said mucosa spaced from the wall 2. The elements 20B keep the oral mucosa spaced from both the wall 2 and the base 3.

The elements 20A, as well as the elements 20B, are present in a number preferably equal to six. In particular, each element 20A and each element 20B is preferably interposed between two consecutive grooves 8. Since the grooves 8 are present in a number preferably equal to six, between two consecutive grooves 8 there is always a pair of elements 20, one belonging to the group 20A and the other belonging to the group 20B. In addition to this, as the grooves 8 branch off from the hole 7, the elements 20B form a crown around the latter. Advantageously, this more preferred arrangement of the elements 20 makes the risk that both the hole 7 and the grooves 8 are obstructed by the oral mucosa of a patient more unlikely. Even more preferably, the elements 20A are coplanar to respective elements 20B. More precisely, each element 20A is coplanar to the element 20B interposed between the same pair of consecutive grooves 8. The planes in which the element pairs 20A and 20B lie are preferably passing through the axis 5. As a result of this, an orthogonal projection of the elements 20A on the wall 2, as well as an orthogonal projection of the elements 20B on the wall 2 or on the base 3, does not overlap either the hole 7 or the grooves 8.

Advantageously, this even more preferred arrangement of the elements 20 is such that they do not obstruct the saliva entry in the cap 1 .

All the elements 20 are preferably oriented so that the end 22 lies on the opposite side of the base 4 with respect to the end 21 . In other words, with reference to the orientation of the cap 1 visible in figures 1 and 3, preferably not only the elements 20B, but also the elements 20A protrude both transversally and upwards.

Advantageously, the aforementioned orientation causes the elements 20 to oppose optimally to an approach of the oral mucosa to the wall 2 and to the base 3.

More preferably, the elements 20 are inclined, with respect to the axis 5, by an angle having a width preferably of between 40° and 70°. More preferably, with respect to axis 5, the elements 20A are inclined by an angle having a width of 66° and the elements 20B are inclined by an angle having a width of 42°. If the elements 20, instead of being straight are, for example, curvilinear, the aforesaid inclinations with respect to the axis 5 are those of a straight line passing through the ends 21 and 22.

The elements 20 have a length preferably of between 2 mm and 3 mm. More preferably, the elements 20A are 2.8 mm long and the elements 20B are 2.3 mm long. As said with reference to the inclination of the elements 20, if the latter, instead of being straight are curvilinear, for example, the aforesaid lengths correspond to the distance between the ends 21 and 22.

Advantageously, with reference to the depression which is generally created inside the cap 1 when the latter is connected to a cannula of a saliva ejector, the aforesaid dimensions are sufficient to prevent the oral mucosa from contacting the wall 2 or the base 3 due to the aforesaid depression.

Figure 4 shows a saliva ejector 30, again according to the invention, comprising the cap 1 reversibly connected to a cannula 31 at the base 4. More precisely, the cannula 31 partially penetrates the cap 1 through the opening 9, so as to be connected by interlocking to the wall 2. As mentioned above, when the saliva ejector 30 is inserted into a patient's mouth, the hole 7 and the grooves 1 of cap 8 allow saliva to enter it and the opening 9 allows the passage of said saliva from the cap 1 into the cannula 31 .

On the basis of the description provided for a preferred exemplary embodiment, it is obvious that some changes may be introduced by those skilled in the art without departing from the scope of the invention as defined by the following claims.