REMOTELY CONTROLLED DENTAL TREATMENT APPARATUS
This invention relates to an apparatus for the remote dental treatment of a patient, whereby the apparatus can be mounted within a patient's jaw and operations can be controlled remotely by the dental surgeon. In particular the invention relates to an apparatus which can be used for the examination and restoration of teeth, including preparation of cavities, sealant restorations, crown and bridge abutments, checking of parallelism and the preparation and examination of endodontic treatments.
Generally the preparation of teeth for various treatments is completed manually by the dental surgeon. The efficacy of the preparation and treatment depends on the eye and hand skills of the dental surgeon. All forms of dental treatment are completed in this way, using magnification occasionally, but depending ultimately on the skill and frame of mind of the dental surgeon at any given time.
This has the disadvantage that microscopic detail is difficult to visualise, and the skill of the operator may be variable from one person to the next and within
the same person from day to day.
A further disadvantage is that patients are required to keep their mouths open for long periods of time, to allow easy access and visibility by the dental surgeon.
The angle of view afforded by looking through a patient's open mouth is limited. The dental surgeon has no way of ensuring that bridge and crown abutments are parallel, except by eye, which does not give highly accurate results.
There are a great many postural problems associated with dentistry, causing many dental surgeons acute back problems, due to the need for dental surgeons to bend over for prolonged periods of time over the face of a patient.
It is an object of the present invention to provide an apparatus which overcomes the above disadvantages.
According to a first aspect of the invention there is provided a dental preparation apparatus comprising a mouthpiece, a dental tool mounting means, and guide means adapted to allow movement of said dental tool mounting means in at least two directions.
Preferably the mouthpiece is shaped to fit a patient's mouth and/or jaw. Preferably the mouthpiece is moulded from a soft elastomeric material, most preferably a thermoplastic material.
Preferably the apparatus further comprises a lever arm to which said dental tool mounting means is attached.
Preferably the guide means comprises a pair of guide
rails arranged in two mutually perpendicular directions. Preferably said apparatus further includes drive means for moving said tool mounting means. Preferably said drive means comprises lead screws, whereby rotation of a lead screw causes said tool mounting means to move in one of said two mutually perpendicular directions. Preferably the mouthpiece is adapted to fit within a patient's mouth such that the plane containing said two mutually perpendicular directions is substantially parallel to the plane of the teeth of an upper or lower jaw of said patient.
Preferably said lever arm is adapted to allow movement of said tool mounting means in a direction perpendicular to the plane containing said two mutually perpendicular directions.
Preferably the apparatus further comprises rotary motor means for driving said lead screws. Said motor means may be electric or pneumatic. Said motor means may comprise turbines driven by compressed air.
Preferably the apparatus further comprises position control means for said tool mounting means. Preferably said position control means comprises one or more springs, one of which may be a shape memory alloy spring through which an electrical current may be passed.
Preferably the apparatus further comprises a camera means which may be attached to said tool mounting means. Preferably the apparatus further comprises a video imaging system, whereby images produced by said camera means are displayed at a remote station.
Preferably the apparatus further comprises a remote
A control means for controlling the operation of said motor means and/or said position control means an/or a dental tool mounted in said dental tool mounting means. Preferably the control means includes means for controlling the movement and speed of said operation.
According to a second aspect of the invention there is provided a method of using a dental preparation apparatus comprising a mouthpiece, a dental tool, a dental tool mounting means and drive means, whereby the movement of the dental tool mounting means by the drive means and the operation of the dental tool are controlled by the operator at a remote station.
Preferably the dental preparation apparatus is an apparatus according to the first aspect of the invention.
An embodiment of the invention will now be described, by way of example only, with reference to the accompanying figures, where:
Fig 1 is an elevation on an apparatus according to a first aspect of the invention;
Fig 2a is an elevation on the mouthpiece of the apparatus of Fig 1 ;
Fig 2b is an elevation on the mounting platform of the apparatus of Fig 1;
Fig 2c is an elevation on the tool assembly of the apparatus of Fig 1;
Fig 3 is a plan on the apparatus of Fig 1;
Fig 4 is a sectional view on line IV- IV of Fig 3 showing the dental preparation device;
Fig 5 shows an alternative dental preparation device which may be used with the apparatus of Fig 1; and
Fig. 6 is a perspective schematic view of an apparatus according to a second aspect of the invention.
Referring to Fig 1 there is shown an apparatus which is intended to be used as an aid to dental surgeons in the preparation of teeth for treatment, the viewing of the treatment areas, the application of treatments, and the delivery of anaesthesia.
It consists of two main components: a tooth preparation or treatment device assembly 4 (eg a drill, dental laser, micro air abrasion device, etc) mounted on a mouthpiece 2 (Fig 1) and a control interface (not shown) for the dentist. The preparation or treatment device assembly and mouthpiece are shown in more detail in Figs 2a, 2b and 2c. The mouthpiece 2 is moulded from a soft thermoplastic elastomer to fit an individual patient's mouth. Alternatively the mouthpiece 2 may be a universal mouthpiece adapted to fit a variety of mouth sizes of different patients. Onto the mouthpiece 2 is bonded a mounting platform 3 onto which the mechanism or tool assembly 4 for moving the tool or preparation or treatment device 20, 30 can be mounted. As an alternative it is possible to form the mouthpiece 2 and tool assembly 4 as a single integral unit, negating the need for a separate mounting platform 3. Throughout the specification the term tool is used to include preparation or treatment device 20, 30. However it should be understood that the tool 20, 30 mounted on the tool assembly 4 can be a
preparation device, a treatment device, a device for applying a material or a device for applying an anaesthetic.
Referring to Fig 3 there is shown in more detail the mechanism for moving the tool 20, 30 on the tool assembly 4. The tool assembly consists of a body 5 which houses the moving parts . The body 5 can be any shape to suit the mouth cavity of the patient, but in practice a rounded rectangular shape has been found to be effective, since it avoids sharp corners which may be uncomfortable for a patient. The body 5 has an aperture 6 through which the tool 20, 30 can reach the tooth to be treated.
Inside the body or housing 5 are a pair of motors 11, 14 which drive a pair of mutually perpendicular lead screws 12, 15 which are free to rotate in bushes 12a, 15a which are also located in the housing 5. The motors 11, 14 may be pneumatic, hydraulic or electric. The motors are powered by cables or pneumatic lines 10. The movement of sub-assembly 7 in the direction of arrow 40 is controlled by rotation of the first motor 11 and first lead screw 12. Angular rotation of the sub-assembly 7 is prevented by guide bars 13, along which the sub-assembly 7 is free to slide.
The second motor 14 and lead screw 15 are mounted in the sub-assembly 7 and move in the direction of arrow 40 with the sub-assembly 7. A connector 17 is mounted onto the second lead screw 15. Rotation of the connector 17 when torque is applied is prevented by guide bar 16, which passes through the connector 17. Rotation of the lead screw 15 causes the connector 17 to move in the direction of arrow 41.
The lead screws 12, 15 therefore provide movement along two generally horizontal axes 40, 41 in the plane of the patient's mouth. A dental tool 20, 30 is attached to the connector 17 by means of a connecting arm 21. The connector 17 provides movement in the generally vertical direction, perpendicular to the plane of the patient's mouth. This is shown in more detail in Fig 4.
The connector 7 consists of a threaded insert 24 which runs on the lead screw 15 and a sleeve 27 which attaches to the guide bar 16. Vertical movement of the tool 20, 30 is achieved by demountably attaching it to a tool holder 28 which is attached to the end of the connecting arm 21. The arm 21 is pivotally mounted about a pivot point 22. The arm is held in the "up" position by a compression spring 26 mounted between the connector 17 and the arm 21, and can be lowered by passing a small current through a shape memory alloy spring 23 which is also mounted between the connector 17 and the arm 21 and is adapted to provide a tension force greater than the compression force in spring 26 when a control signal is applied through electrical circuit 25. Alternative motor means for controlling the vertical movement of arm 21 are possible, including a galvanometric motor, a pneumatic motor, a hydraulic motor or an electromagnet.
In use the tool 20 (a standard dental drill head is shown by way of example) may be moved along three degrees of freedom by lead screws 12, 15 and vertical control spring 23 to bring the drill to the required working location on the tooth to be treated.
Referring to Fig 5, there is shown a dental drill head 30 modified to include a connection to a dental video
imaging system or endoscopic system 31, a number of which are currently on the market, which allows the dentist to clearly view the working area. The drill head 30 may also include a device for keeping the camera lens free from condensation.
A system of electronically controlled valves allows the dentist to control the movement and speed of the tool 20, 30 from a standard personal computer, vision being supplied to the computer screen via the video imaging system 31, allowing accurate control.
Referring to Fig. 6 there is shown an embodiment of the invention using a U-shaped mouthpiece 102. The mouthpiece has two legs 106, in each of which is an aperture 105. The mouthpiece is adapted to fit over the jaw of a patient, so that the teeth to be treated are accessible through the aperture 105. Onto the mouthpiece 102 is bonded a mounting platform 103 onto which the mechanism or tool assembly 104 (shown only schemsatically) for moving the tool 20, 30 can be mounted. The mounting platform 103 is also provided with an aperture 107. The tool assembly 104 is similar to the assembly 4 illustrated in Figs 2a and 3.
The advantages of the invention and/or the ways in which the disadvantages of previously known arrangements are overcome, include:
a. high quality magnified image; b. remote access allows awkwardly located teeth to be seen; c. patient need not maintain a wide gap; d. dentist has improved control over movement of drill; e. parallelism is easy to achieve in preparation of
crowns and bridges; f. endodontic treatment easier to see; g. patient comfort is achieved more easily; h. dentist comfort is improved, eliminating need for constant stooping and improving posture
These and other modifications and improvements can be incorporated without departing from the scope of the invention.