US-12622770-B2 - Suction handpiece for a dental treatment unit

US12622770B2US 12622770 B2US12622770 B2US 12622770B2US-12622770-B2

Abstract

A suction handpiece for a dental treatment unit has a negative pressure connection which can be connected with a negative pressure source of the treatment unit. A saliva connection of the suction unit can be connected with a saliva suction cannula and an atomized spray connection that can be connected with an atomized spray suction cannula. A branched flow path connects the negative pressure connection with both the saliva connection and the atomized spray connection and includes a branching section on which a negative pressure channel ending on the negative pressure connection divides into a saliva channel ending on the saliva connection and an atomized spray channel ending on the atomized spray connection. The atomized spray channel at its narrowest point has a first cross sectional area which is at least twice as large as a second cross sectional area at the narrowest point of the saliva channel.

Inventors

Martin DURRSTEIN
Andreas Hagele

Assignees

Dürr Dental SE

Dates

Publication Date: 20260512
Application Date: 20221122
Priority Date: 20200525

Claims (20)

1 . A suction handpiece for a dental treatment unit, wherein the suction handpiece comprises: a negative pressure connection that is configured to be connected with a negative pressure source of the treatment unit, a saliva connection which is configured to be connected with a saliva suction cannula, an atomized spray connection which is configured to be connected with an atomized spray suction cannula, and a branched flow path which connects the negative pressure connection with both the saliva connection and the atomized spray connection, wherein the flow path includes a branching section in which a negative pressure channel ending on the negative pressure connection divides into a saliva channel ending on the saliva connection and an atomized spray channel ending on the atomized spray connection, wherein the atomized spray channel has a tapering section directly adjacent to the branching section and upstream of the branching section, and wherein the tapering section has a cross-sectional area that is tapered relative to adjacent sections of the atomized spray channel, wherein the tapering relative to a section opposite to the branching section is 20% to 35%.
2 . The suction handpiece according to claim 1 , wherein the atomized spray channel at its narrowest point has a first cross sectional area A1 which is larger than a second cross sectional area A2 at the narrowest point of the saliva channel.
3 . The suction handpiece according to claim 2 , wherein the first cross sectional area A1 is at least twice as large as the second cross sectional area A2.
4 . The suction handpiece according to claim 3 , wherein a ratio m=A1/A2 has a value between 3 and 100.
5 . The suction handpiece according to claim 4 , wherein the ratio m has a value between 5 and 50.
6 . The suction handpiece according to claim 2 , wherein the first cross sectional area A1 has a value between 25 mm 2 and 120 mm 2 , and the second cross sectional area A2 has a value between 1.7 mm 2 and 8 mm 2 .
7 . The suction handpiece according to claim 2 , wherein the first cross sectional area A1 has a value between 35 mm 2 and 100 mm 2 , and the second cross sectional area A2 has a value between 2.5 mm 2 and 8 mm 2 .
8 . The suction handpiece according to claim 2 , wherein the first cross sectional area A1 and the second cross sectional area A2 are circular.
9 . The suction handpiece according to claim 1 , wherein the negative pressure channel and the atomized spray channel each extend in a straight line and have longitudinal axes aligned with one another.
10 . The suction handpiece according to claim 9 , wherein the saliva channel has an inclined portion having a longitudinal axis, which is pointing to the branching section, and wherein the longitudinal axis of the saliva channel to the longitudinal axis of the negative pressure channel which is an angle between 10° and 45°.
11 . The suction handpiece according to claim 10 , wherein the angle is between 20° and 30°.
12 . The suction handpiece according to claim 9 , wherein the saliva channel has another section having a longitudinal axis which extends parallel to the longitudinal axis of the atomized spray channel.
13 . The suction handpiece according to claim 1 , wherein a cross sectional area of the saliva channel is continuously or stepwise tapered towards the saliva connection.
14 . A suction device comprising: the suction handpiece according to claim 1 , a saliva suction cannula connected with the saliva connection, and an atomized spray suction cannula connected with the atomized spray connection.
15 . The suction device according to claim 14 , wherein the saliva suction cannula is plastically bendable and the atomized spray suction cannula is provided with at least one pivotal joint or ball-and-socket joint.
16 . The suction device according to claim 14 , wherein at least one of the cannulas is detachably connected with the handpiece.
17 . The suction device according to claim 14 , wherein the saliva suction cannula and the atomized spray suction cannula are formed in such a manner that during treatment a suction end of the saliva suction cannula is configured to be placed in the oral cavity of a patient and one suction end of the atomized spray suction cannula is configured to be placed outside the oral cavity of the patient.
18 . The suction device according to claim 14 , wherein the atomized spray suction cannula has a suction head fitted in a replaceable manner.
19 . The suction device according to claim 14 , wherein the saliva suction cannula is provided with a protective cap at the end which has several openings configured to suck in liquids.
20 . The suction device according to claim 14 , wherein the atomized spray suction cannula is open at an end and passes into a collecting hopper which, due to its dimensions, is configured so that the collecting hopper cannot be placed in the oral cavity of a patient.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Continuation of International Patent Application No. PCT/EP2021/062332, filed May 10, 2021, which claims priority to European Patent Application No. 20176359.6, filed May 25, 2020; the disclosures of both applications are incorporated herein by reference in their entirety. FIELD The invention relates to a suction handpiece for a dental treatment unit which can be connected with cannulas as well as a negative pressure source located in or allocated to the treatment unit. BACKGROUND Certain activities such as the preparation of teeth, the removal of fillings, crowns and bridges or the removal of plaque require the use of instruments which rotate with high speed. In order to avoid damages in the pulp dentin zone, water is supplied during treatment for the purpose of local cooling. In this process, atomized spray, also referred to as aerosols, is created. The atomized spray leaving the patient's mouth contains droplets which may include cooling water, saliva and blood. A high risk of infection emanates from said mixture. Said atomized spray leaving the patient's mouth can, if no countermeasures are taken, still be detected at a distance of several meters, and settle on surfaces in the treatment room. Thus, the individuals present in the treatment room apart from the patient, in particular the attending dentist and his or her support staff, inhale the atomized spray and might become infected, as the case may be. The most efficient countermeasure against distribution of the atomized spray is to suck it off by means of a cannula while the atomized spray is still in the oral cavity of the patient. In practice, one distinguishes between a high volume suction, as it is mainly used in Europe, and a medium volume suction which has established itself outside Europe. In the case of the high volume suction, volume flows between 250 and 350 l/min are achieved by the interaction of a negative pressure generator, tubes and cannulas; the suction cannulas typically have an inner diameter of approximately 12 mm. In the case of the medium volume suction, the volume flow is typically between approximately 100 and 250 l/min, with the cannulas having an inner diameter of approximately 9 mm. But during dental treatment, as the case may be, not only the atomized spray but also liquids such as blood and saliva with particles contained therein must be sucked off. For this purpose, a smaller cannula is connected to the negative pressure source via a separate tube. This smaller cannula, which is usually called saliva drain or saliva ejector, has a clearly smaller cross-section with an inner diameter between approximately 3 and 5 mm, and is provided with a small protective cap at the end into which several openings with a clear width of approximately 0.4 to 0.7 mm are integrated. The protective cap prevents that larger particles are sucked in which might cause obstruction of the saliva ejector. Due to its small cross-section, the saliva ejector is not suitable for sucking off the atomized spray. The volume flow of air, when no liquid is sucked in, is only approximately 80 to 120 l/min. Since the volume flow is generally impeded by soft tissue on which the protective cap rests, the atomized spray cannot be efficiently sucked off by the saliva ejector alone. Depending on the country, dental treatment, including suction, is carried out in different ways. In German speaking countries, suction of liquids and atomized spray is usually assisted by the dental assistant so that the dentist can entirely concentrate on the actual treatment. In most other countries, such as, for example, in France, however, the dentist works alone. But without assistance by a dental assistant, it is difficult to insert the saliva ejector and in addition the cannula for suction of the atomized spray into the patient's oral cavity, and to carry out actual treatment at the same time. As a consequence, often only suction of the saliva is performed but the atomized spray can leave the patient's oral cavity largely unhindered. From WO 2011/120668 A1, a suction device is known where two saliva ejectors come off from one handpiece. One of the two saliva ejectors has a hook-shaped bend by means of which it can be fitted to the corner of the mouth of the patient to be treated so that it need not be held by hand. The end of said saliva ejector lies in the deepest accessible portion of the oral cavity parallel to the lower row of teeth of the corner of the mouth, and sucks off excess water and saliva from there. The other saliva ejector, which is deformable, is oriented to a location where a selective suction is requested, and at the same time keeps the tongue away. SUMMARY It is the objective of the invention to specify a suction handpiece for a dental treatment unit which permits ergonomic working and a high protection against infections. This objective is achieved according to the invention by a suction handpiece f