AU622461B2 - Dental bite block wax removal and softening apparatus - Google Patents

Description

Signature Of applicant or Australian attorney (Signiature) THE COMMISSIONER OF PATENTS This form must be accompanied by either a provisional specification (Form 9 and true copy) or by a complete specification (Form 10 and true copy).

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PATENTS ACT 1952 46 1 P/00/01 I Form COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. CI: Application Number: Loaged: 4 Corriplete Specification-Lodged: Accepted: Lapsed: ft a Published: V Priority: Related Art: T 1

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LODGEMENT UNIT 1) AMOUNT RECEIVED 4 2) A MOUN T ENi V 1- D0ON T 14E SYST EM.. I 3) AMOUNT UN D'i;R.A) 4) AMOUNT O\TPJ-AID BY :7, (OVERPAID F;7E HTELD AGAINST RECEIPT) "2 07,, TO BE COMPLETED BY APPLICANT Nj~ame of Applicant: "Address of Applicant: Actual Inventor: ROLFE DIETER WICKE, 4 BEAUTY CRES, ,Ls r: 3ATFNIANS L A1 N S W 2536.

ROLFE DIETER W ICKE, Q~e f7@ TA4~~ DS34 Address for Service: Complete Specification for the invention entitled.: "DENTAL BITE BLOCK WAX REMOVAL" AND SOFTEN ING APPARATUS".

The following statement is a full description of this invention, including the best method of performing it known to me:- Note: The description is to be typed in double spacing, p!c~a type face, in an area not exceeding 250 mmi in depth and 160 mm lin width, on tough white paper of good quality and it is to be inserted inside this form.

1 4599/78- L Printed by C. I. THOMPSON~, Commonwealth Government Printer, Canberra (eg by assignment....by mesne aignment, by consent, etc) (eg by assignment, by mesne assignment, by consent, etc) (Continued over)

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TITLE:

"DENTAL BITE BLOCK WAX REMOVAL AND SOFTENING APPARATUS".

ABSTRACT OF THE DISCLOSURE 0040 o q 00 4 o 0 *00 it 'r(C 0 r A convenient, easy to use, wax melting apparatus which enables uniform softening of the wax of a dental bite block has a heated plate with associated drainage, on which is mounted an array of thermally conductive, parallel, elongate fins. The plate and fins are heated by a heating element which is located within a housing on which the plate is mounted. The heating element is preferably an electrical heating element which is thermontatically controlled. The housing defines an externally accessible compartment underneath the drainage, to permit the collection of molten wax drained from the plate.

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ej ll^ *referred to in the declaration under Article 8 of the PCT *is *are the application(s) first made in a Convention country in respect of the invention.

O A request has been made under Section 96 of the 1990 Act (or Section 142AA of the 1952 Act) to disregard the following application.

I rr id i -c: i r 1 1 2 o oo os 00 0 00 0 0 00 0 0D 0 O 00 Technical field This invention concerns the manufacture of dentures.

More particularly, it concerns apparatus for use in melting and softening the wax of a dental bite block, to enable accurate measurement of the "bite" of a patient to be fitted with dentures.

Background to the invention When a dental patient requires dentures or false teeth, the normal steps in the manufacture of the 10 dentures are as follows:taking an impression of the gums and teeth (if any) in the upper and lower jaw of the patient; constructing a plaster model of the upper and lower jaw of the patient; determining the "bite" of the patient; and constructing the dentures.

The determination of the bite of the patient is a most important step in this procedure. If the bite is under-estimated, the patient will experience overclosi.g of the jaw when the dentures have been fitted. Overclosing causes stress in the muscles of the jaw which leads to an aching jaw, earache, headaches and (in time) distoration of the lips at their edges so that saliva can dribble from the mouth, which leads to the development of unsightly and painful sores.

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j a r"\ iir 1! ii -3- If the bite is over-estimated, the dentures prevent the proper closing of the jaw. This condition is known as an "open bite" condition. In extreme (.but not uncommon) instances of open bite, the user of the dentures cannot open his or her jaw sufficiently to insert normal food into the mouth. This eventually leads to a liquid or almost liquid diet, with I consequent mental stress and embarrassment of the (cC user of the dentures when attending social functions.

o~ 10 The standard technique for measuring the bite of a 0t *patient involves the insertion of a pair of wax "bite t blocks" into the mouth of a patient. The upper bite block is shaped, using the plaster model of the upper jaw, to fit against the pallet and gums (and teeth if present) of the patient, with a wax rim over the o teeth region. The lower bite block usually has a 0" 0shape generally like a horse-shoe, adapted to fit over the lower gum (and teeth if present), again with a wax rim above the teeth region. Before the blocks 20 are inserted into the patient's mouth, an estimate of the bite is obtained either from visual inspection of the patient's jaw, or (preferably) using a Wills bite Sgauge. The rims of the wax bite blocks are then reduced in thickness, by melting wax from them, until they correspond approximately to, but slightly in excess of, the estimated bite of the patient. The rims of wax are then softened and the wax bite blocks are inserted into the mouth of the patient. The bo ft o a1 wa ri abv th ethrgon eor h bok I |r 20 are inere int the~ pain'smuh a siat f -4patient then closes his or her jaw normally so that the actual bite can be accurately determined from the displacement of softened wax.

The removal of wax from the bite blocks before they are inserted into a patient's mouth has been effected, for many years, using a paint scraper o oo" heated by the flame of a bunsen burner. The excess wax is collected in any receptacle available.

Normally this procedure requires the dentist to leave 10 the patient to perform the wax removal in a separate O 0 region of the surgery (usually a separate room), for *s"ao the wax removal is a messy business.

The subsequent softening of the remaining wax of the rims of each bite block has hitherto been effected o 15 using a knife blade, also heated by the flame of a o'o bunsen burner, which is inserted into the remaining wax rim in a criss-cross manner. The wax encountered 0 by the heated blade is melted and the surrounding wax is softened. Usually, the knife blade has to be reheated at laast once during this wax softening °procedure.

y Although this technique has been adopted for many years, it is not entirely satisfactory. Apart from its general crudity and messiness, the procedure is time consuming for the dentist. More importantly, however, the softening of the wax rims after removal of the excess wax from the bite blocks is not always Suniform. Thus, when a patient closes his or her jaws 1 2 i s. i to enable the true bite to be determined, instead of a uniform, natural closing movement of the jaws which occurs with properly softened wax, the presence of a hard region of wax in one of the rims will cause the patient to adjust his or her bite, in the manner normally used when chewing a firm food object, as the jaws are closed. This results in a distorted bite being observed. If this distorted bite is used in the manufacture of the patient's dentures, the dentures will not have the ideal shape for the C patient's mouth and will not bite correctly in use.

SCOverclosing or an open bite condition may be produced.

Disclosure of the present invention It is an object of the present invention to provide apparatus which, when used, speeds up the preparation iL, of wax bite blocks and ensures that the softened wax rim of a bite block has been uniformly and properly Ssoftened.

This objective is achieved by providing a heated o plate which is provided with a drain for molten wax, Hwith an array of thermally conducting fins mounted in conducting relationship with a zone of the heated plate. The region of the plate which is not covered by the array of fins is used to melt wax rapidly from a bite block, in place of the conventional paint scraper. The heated fins are used in place of the wax knife to melt the wax of the rim of a wax block by placing the wax block on the array to melt the 1 j- 1

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6 wax encounted by the fins, then (ii) removing the wax block, rotating it (by hand) by about 90°, then placing it again on the fins. An electric heater mounted on or closely adjacent to the underside of the plate raises the temperature of the plate to a predetermined level and maintains it at that level.

Such apparatus can be assembled in a compact manner "a o to provide an attractive, as well as functionally *OeO beneficial, additional item of equipment.for a dental o o0 10 surgery.

o 00 °o Thus according to the present invention, there is o provided a bite block wax removal and softening apparatus comprising:a thermally conducting plate, said plate being 15 generally horizontal in use but with at least eo0 o part of its surface inclined towards a drainage *o aperture therein; a heating element mounted below said plate; and 0 an array of thermally conductive, elongate fins having their elongate directions parallel, said array being mounted on a zone of said plate, .0:0 whereby heat from said heating element is conducted via said plate to the array of fins.

Normally the heating element will be an electrical heating element with an associated thermostatic heat control arrangement to regulate the temperature to which the plate and the array of fins are heated.

i j~ -7 7 In the preferred form of the present invention, the drainage aperture in the plate is located towards one edge of the plate and the heating element and its associated control system are enclosed within a housing which is shaped to define a space under the drainage aperture where a receptacle for receiving melted wax can be placed.

These and other features (some optional) of the r preferred embodiment of the present invention will be ,1 0 more readily appreciated from the following description of the preferred embodiment, in which reference will be made to the accompanying drawings.

Brief description of the drawings SFigure 1 is a perspective sketch from the front of the preferred embodiment of the wax melting and softening apparatus of this invention.

Figure 2 is a perspective sketch from the rear of the embodiment of Figure i.

Figure 3 is a sectional view, partly schematic, at III-IIT of Figure i.

Detailed description of the illustrated embodiment The equipment illustrated in Figures 1 and 2 comprises a housing 10 on which is mounted a thermally conducting plate 11. In the preferred embodiment, the plate 11 is a stainless steel plate, but the plate 11 need not be of stainless steel. It 8 may, for example, be an aluminium alloy plate, or a chrome-plated mild steel plate. The surface of the plate 11 is generally horizontal when the apparatus is in use but, as will be clear from the drawings, the plate is dished slightly so that any liquid collected on the plate will flow to a drainage aperture 13, beneath which a receptacle 18 for liquid is usually positioned.

An array 12 of elongate fins is mounted over one zone of the plate 11. The present inventor has produced S(arrays of twenty-four fins of generally triangular cross-section, extending from a base 12A, as an aluminium extrusion. After a length of the extrusion suitable for use in the present invention has been cut from the extrusion, it is sec~_r ,d in. contact with "c the plate 11 by four screws, located close to the Scorners of the array 12. Such a mounting arrangement has been found to hold the base of the array in contact with the plate 11, and to ensure effective heat transfer from the plate 11 to the fins of the array 12. However, an adhesive may be used (in addition to, or instead of, the four mounting screws) to bond the base of the array of fins to the plate

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7 11 The embodiment illustrated in Figures 3. and 2 is an electrically-powered realisation of the present invention. Accordingly, it includes a heat setting control knob 14 to set the temperature at which the plate 11 and the fins 12 are maintained. An ir A i- -9indicator lamp 15 glows when power is connected to the apparatus. The heat control system, which is referred to in more detail below, is a conventional feature of small electrical appliances which incorporate a heater, as is the indicator lamp It will be appreciated that the heating of the plate 11 and the fins 12 may be effected by a gas burner positioned beneath the plate 11. In such an arrangement, conventional gas control taps, and optionally a conventional gas ignition system, will C be incorporated into the apparatus.

Reverting now to the embodiment of Figures 1 and 2, a pair of handles 16 extend from opposed sides of the housing 10 for ease of movement of the apparatus. As c:c 15 noted above, the housing 10 will normally be shaped to provide a location 17 underneath the drainage aperture 13 where a collector 18 of liquid wax may be positioned.

The internal assembly of the embodiment illustrated i 020 in Figures 1 and 2 is shown, partly schematically, in Figure 3. An aluminium plate 21 conducts heat from an electrical heating element 20 to the plate 11 and thus also to the base 12A of the fins 12. The heating element is a conventional electrical heating element, with a conventional thermostat control arrangement. The probe 22 for the thermostat is normally located, as shown in Figure 3, within a groove in a thin block 23 of an insulating material.

&1 1: ;11 rr;~ l i; 10 o so *a 0 ar 00 0o a4 a 4 o *a o o U o ra a~a a o 04( aB a a a 4 A transverse plate 24, supported on the housing holds the insulating block 23, the heating element the aluminium plate 21 and the top plate 11 in contact with each other. At least one locating screw may be used to ensure that these components are correctly positioned adjacent to each other, and cannot slip relative to each other should the apparatus be knocked or dropped.

In the illustrated embodiment, the handles 16 are 10 attached to the housing 10 and to respective flanges at the edges of the inner transverse plate 24. Four feet 19, of conventional type, are attached to the base plate 25 of the apparatus, which may be formed integrally with the housing 15 The first batch of units of the present invention has been marketed in Australia under the trade mark BITEMATIC. Each unit in this batch measured 90 mm high (at the front of the unit) and had a width and depth of 165 mm. The heating element was a 340 watts 20 element, which consumed a maximum current of 1.45 amps with the heating control set for maximum temperature of the plate 11. The entire batch was received enthusiastically by dentists who have found the present invention to be a convenient, efficient and time-saving piece of equipment, which is easy to clean (cleaning requires only a wiping of the plate 11 with a tissue while the apparatus cools after use).

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i 11 It will be clear to designers and constructors of electrical equipment that various modifications to and variations of the illustrated embodiment, additional to those already mentioned in this description of the invention, may be made wiU-bout departing from the present inventive concept.

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Claims (6)

1. 2. Apparatus as defined in claim i, in which each of said fins is generally triangular in cross-section and extends from a base, said base being held in contact with said plate. 1 3. Apparatus as defined in claim 2, in which said base and fins are formed integrally as an aluminium extrusion.
2. 4. Apparatus as defined in claim 3, in which said base is held in intimate contact with said plate by a plurality of screws extending through said plate and into said base. -S The following statement is a full description of this invention, including the best method of performing it known to me:-" Note: The description is to be typed in double spacing, pica type face, in an area not exceeding 250 mm in depth and 160 mm in i 'width, on tough white paper of good quality and it is to be inserted inside this form. S14599/78-L Printed by C. J. THOMPSON, Commonwealth Government Printer, Canberra iv f- i r- t 13 Apparatus as defined in claim 1, including a thin block of thermally conducting material positioned between said heating element and the underside of said plate, said heating element and said thin block being held in contact with each other.
3. 6. Apparatus as defined ir. claim 5, including an *fi insulating block underneath and in contact with said heating element, said insulating block S, having a groove in its upper surface in which is °a located a probe of a thermostatic control unit 2 for said heating element.
4. 7. Apparatus as defined in claim 6, in which said plate is mounted on a housing and said thermally 0,a conducting block, said heating element and said o insulating block are mounted within said housing on a transverse inner plate which is supported 2on said housing.
5. 8. Apparatus as defined in claim 7, in which said housing is shaped to define an externally accessible compartment underneath said drainage Saperture, and a molten wax collecting receptacle is located within said compartment.
6. 9. Apparatus as defined in claim 1, in which said plate is a stainless steel plate; said heating element is a thermostatically controlled heating element; 4 4 t RA II .m 14 heating element is located in a groove in a block of insulating material located beneath said heating element; a housing supports said plate and its array of fins; (f said housing is shaped to define an externally accessible compartment beneath said drainage aperture; a molten wax collection receptacle is located within said compartment; and an internal transverse plate within said housing supports said insulating block, C said heating element and said aluminium block in contact with each other. a I (d a robeforthe herostaic ontrl o th i eatng lemet i loate in grovein :I