GB2211457A

GB2211457A - Dental apparatus

Info

Publication number: GB2211457A
Application number: GB8725215A
Authority: GB
Inventors: John Ells
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-10-28
Filing date: 1987-10-28
Publication date: 1989-07-05
Also published as: GB8725215D0

Abstract

Dental apparatus for use in tooth restoration comprises an array of probe elements (24) individually supported in side-by-side relationship in a support member (10), the probe elements being longitudinally displaceable from an extended position to a retracted position with respect to the support member and lockable by a screw clamp (21). Preferably, a lateral bar (25) is slidingly mounted behind the probe elements to restore them from the retracted to extended position. <IMAGE>

Description

DENTAL APPARATUS This invention relates to dental apparatus, in particular for use in the restoration of teeth.

Dental restorative surgery, for example the formation of a crown for attachment to one or more tooth preparations, requires the formation of a metal coping or substructure which is to be attached direct to the preparation and is generally provided with a porcelain coating which is fired, trimmed and glazed to simulate the appearance of the natural tooth, before being cemented it position on the preparation. As far as possible, the shape of the coping should reproduce that of the tooth being replaced, unless cosmetically or for some other reason it should be considered desirable to re-fashion the shape or angle of the tooth. However, in most cases it is the objective of the dental surgeon to reproduce the shape and angle of the original tooth as closely as possible, and this is done by taking an impression of the tooth to act as a model for use in formation of the crown.

In preparative work on the tooth, it is necessary to remove, from the outer portion of the tooth, the enamel covering together with underlying dentine equivalent to the intended thickness of the metal coping and porcelain of the crown. However, removal of the correct thickness of material from the tooth calls for considerable skill and judgement.

It is an object of the present invention to provide dental apparatus that enables the dental surgeon more accurately and reliably to assess when sufficient of the outer portion of the tooth has been removed.

According to the invention, dental apparatus comprises an array of probe elements individually supported in side-by-side relationship in a support member, in which each probe element is longitudinally displaceable from an extended position with respect to the support member.

Preferably the support member is substantially flat and in consequence the probe elements are all in a single plane.

The individual probe elements may be a frictional sliding fit in the support member and/or may be clampable therein, whereby they are displaceble only when in the unclamped position.

In use, and with the probe elements in the extended position and the clamp, if fitted, in the unclamped or free position, the apparatus is offered to the portion of the jaw containing the tooth to be fitted with a crown so that the front ends of the probe elements face towards the teeth, generally from in front so that they face the labial portion thereof, and the apparatus is moved towards the teeth so that individual probe elements are displaced on contacting a tooth and on continuing movement of the apparatus towards the teeth.

When the apparatus is withdrawn from contact with the teeth, the front ends of the displaced probe elements together reflect the shape or contour of those teeth.

On subsequent removal of the enamel and dentine from the tooth to be fitted with a crown, therefore, the dental surgeon need only hold the apparatus against the same teeth and the gap between the ends of the probe elements and the surface of the tooth being prepared gives an immediate visual indication of the amount of enamel and dentine removed.

Generally, approximately 60 probe elements suffice to provide apparatus of sufficient width to contact five or six consecutive teeth in a jaw, each probe element being formed from square or round cross-section wire of transverse dimension of imm or less, preferably 0.7mm or less.

Preferably, the rear ends of the probe elements face towards a transverse bar mounted in the support member, in the plane of the probe elements, the bar being slidable in the support member in the same direction as the probe elements. The bar may therefore be used to move all the probe elements into the extended position and is itself displaced rearwardly by the probe elements on displacement of the latter in contact with teeth.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, of which Figure 1 is a plan view of apparatus according to the invention, Figure 2 shows a cross-section of the apparatus of Figure 1, viewed along the line II-II, Figure 2A is a detail of part of Figure 2, and Figure 3 shows a representation of the apparatus of Figure 1 in contact with teeth.

Referring firstly to Figure 1, the apparatus consists of a support plate 10 of a size convenient to be held in the hand and having a straight leading edge 11.

Extending rearwardly from the leading edge is a shallow depression 12 bounded by side walls 13, 14 and rear wall 15. The floor of the depression is formed with a longitudinal slot 16 and a pair of spaced-apart cross members 17, 18 are formed laterally of the front region of the depression to define a transverse slot 19 (Figure 2) between the floor of the depression and the cross members. Mounted centrally between the cross members is a bridge 20 which is tapped and contains a screw 21 which bears via a leaf spring 22 (Figure 2A) on transverse plate 23 carried between the cross members. Figure 2A shows the screw, leaf spring and plate from the front.

Carried in the transvers slot 19 are approximately sixty needles 24 which may be clamped by plate 22 on tightening of screw 21. On slackening the screw 21, the needles are individually longitudinally slidable within the slot 19, residual friction being applied by virtue of the leaf spring 22.

A transverse bar 25 is slidably mounted in slot 15 and extends across the width of the depression. The rear ends of the needles face the front edge of the bar such that forward movement of the bar causes the needles to slide to an extended position, protruding from the slot 19.

Referring to Figure 3, the apparatus as shown in Figures 1 and 2 and is depicted in contact with teeth, whereby the profile of the front or labial face of the teeth is reflected in the contour of the front ends of the needles. If it is desired to provide a crown for the tooth 31, the needles are clamped by tightening the screw 21 and the apparatus is removed from contact with the teeth. The outer regions of tooth 31 are then ground away to form a preparation and from time to time the apparatus is re-offered to the teeth so that the gap between the surface of the preparation and the ends of the needles indicated by brackets 32 gives an indication of the thickness of enamel and dentine removed. The exterior surface of the preparation is indicated at 33 in Figure 3.

Claims

1. Dental apparatus for use in tooth restoration, the apparatus comprising an array of probe elements individually supported in side-by-side relationship in a support member, each probe element being longitudinally displaceable from an extended position to a retracted position with respect to the support member.

2. Dental apparatus according to Claim 1, in which the support member is substantially flat whereby the probe elements are arranged in co-planar fashion.

3. Dental apparatus according to Claim 1 or Claim 2, in which the probe elements are a frictional sliding fit in the support member.

4. Dental apparatus according to any preceding claim, in which the support member includes clamp means to clamp the probe elements in a displaced position.

5. Dental apparatus according to any preceding claim, in which the support member includes a transverse bar mounted behind the probe elements for sliding movement in the same directions as the probe elements.

6. Dental apparatus according to any preceding claim and including approximately sixty probe elements, whereby the profile of five or six adjacent teeth in an adult human jaw may be recorded.

7. Dental apparatus according to any preceding claim, in which each probe element is square or round in cross section and has a maximum transverse dimension of 1 mm.

8. Dental apparatus constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.