APPARATUS FOR DIAGNOSIS

Abstract: Apparatus for diagnosing an inflammatory condition relating to periodontitis, comprising means (1, 3) for measuring and recording temperature in connection with a periodontal pocket. The apparatus further comprises measuring means (17) with a graduated scale for measuring the depth of the periodontal pocket and in association herewith also provided with means (5) for measuring and recording the temperature difference between the bottom and the mouth of the periodontal pocket.

Description: Apparatus for diagnosis The present invention relates to an apparatus for diagnosing inflammatory conditions m connection with perio- dontitis, and the invention alβo involves a process for such diagnosiβ . The loosening of teeth (periodontitis) is a bacterial- ly caused inflammation in the attachment apparatus of the tooth (periodontium) which, if left untreated results in de- composition of the bone around the tooth (reβorption) and of the tooth loosening its anchorage, the anchorage being ulti¬ mately lost. Periodontitis shall primarily be prevented by good oral hygiene but may also, after being established, be treated. This treatment will mainly be directed to interrupt the progress of the disease. Practically all adultε are to a greater or lesser de¬ gree subjected to the disease, and approximately 10X of the population in the industrialised world develop severe perio¬ dontitis resulting in partial or total loss of the teeth. Periodontitis is initially a disease which to the pa¬ tient lacks βymptoms . However, the dentist can see early signs of an incipient diβeaβe development. The gum around the teeth become red, swollen and bleed easily, i.e. show βignβ of an inflammation. Simultaneously the pocket between tooth and gum will be subject to increased depth. In this pocket additional bacteria will accumulate and proliferate (plaque) . Gradually the bacteria will calcify and calculus will form on the teeth. Synchronously with the formation of plaque the inflammation βpreads in the attachment apparatus of the tooth and the bone surrounding the root of the tooth starts to de¬ compose . The methods available to the dentist to diagnose peri¬ odontitis is measuring the depth of the periodontal pocket around the tooth and registering the tendency for bleeding in connection herewith. However, thiB does not give a full mea¬ sure of the degree of inflammation in the attachment appara- tus of the tooth. Above all these measures give little gui dance for judging how the desease will develop. They rathe reflect what has already taken place. One of the greatest problem in the treatment of per dontitis is to be able to predict around what teeth the periodontitis activity will increase. It has been found th the loss of supporting tissue around the teeth in periodon tis fluctuates, i.e. periods of low disease activity succe periods of high activity. Early signs of this can be seen the degree of inflammation in the environment of the teeth. An incipient increase of the degree of inflammation should treated as soon as possible in order to save as much as po sible of the anchorage of the tooth. The traditional metho (depth of periodontal pocket and bleeding tendency) in ord to estimate this condition are not reliable. A deep period tal pocket does not necessarily mean that the periodontal process is active. A healing process may have started. In same manner a shallow periodontal pocket may not mean that the periodontal disease is inactive. Also a deep pocket ha once been shallow and it is very important to be able to p dict which periodontal pockets are subject to deepening. The cardinal symptoms of a topical inflammatory con tion is calor (temperature increase), dolor (pain), rubor (redness) and tumor (swelling). Out of these the redness (bleeding in the periodontal pocket) and the swelling (in combination with decomposition of alveolar bone, i.e. meas ring depth of periodontal pocket) have traditionally been used to diagnose periodontitis. However, these symptoms of periodontitis are not reliable measures for estimating the activity of the disease. Furthermore, it is not possible t estimate bleeding quantitatively. These traditional method measuring of pocket depth and bleeding tendency, to judge activity of the periodontal process often give misleading results, particularly in an early stage of an active perio A deep periodontal pocket which is bleeding does not alway mean that the process is active. The use of temperature as a measurement for the acti¬ vity of periodontitis is based on the fact that an inflamma¬ tory process in view of increased flow of blood results in an early temperature increase (before the depth of the periodon- tal pocket has increased). However, m the mouth the tempera¬ ture varies between different areas. The gum is varmer the deeper in the oral cavity the measurement is made (32°C to 37°C) . An absolute temperature scale to estimate the degree of inflammation is thus not possible to define. However, the surface temperature in the opening of the periodontal pocket is not affected by a possible inflammation at the bottom of the periodontal pocket . The present invention has for an object to provide an apparatus by means of which inflammatory conditions in con- nection with periodontitis can be diagnoβed m a simple and reliable manner. Another object of the invention is to provide a pro¬ cess for diagnosing the degree of inflammatory condition in connection with periodontitis, which process is based on an estimation of the exterior conditions around a so called pe¬ riodontal pocket. For these and other objects which will be clear from the following disclosure the invention provides for an appa¬ ratus for diagnosing periodontitis in view of its inflamma- tory aspect, said apparatus comprising means for measuring and recording temperature in connection with a periodontal pocket. The apparatus for such diagnosis is provided with a measuring meanB with a graduated scale for measuring the depth of the periodontal pocket and in association herewith also provided with means for measuring and recording the tem¬ perature difference between the bottom and the mouth of the periodontal pocket. The apparatus means for temperature measurement is suitably constituted by a probe which is connected to the measuring means in such a manner that the depth of the perio¬ dontal pocket can be recorded in connection with measuring the temperature at its bottom. The temperature sensor or transducer, which is suit ably positioned at the free end of the probe, can be of di ferent types, of which examples are thermoelements, thermi tors, semiconductor diodes and resistance transducers. In a particularly preferred embodiment of the appar tus according to the present invention the probe and the m suring means are assembled to one unit. In an alternative embodiment of the apparatus according to the invention sai means for temperature measurement may comprise a probe wit two transducers displacable relative to each other, the ap paratus also including a measuring means with a graduated scale for measuring the depth of the periodontal pocket, o end of the probe being permanently connected to the measur means at its free end, whereas the other transducer is ov able along the scale so that the temperature difference be ween the bottom and the mouth of the periodontal pocket ca be registered at the samt time as the pocket depth is meas red. It is obvious for a man skilled in the art that the temperature simultaneously can be monitored at various lev of a tooth pocket by an array of sensors, or transducers. The invention also provides for process for diagnos inflammatory conditions in connection with periodontitis, said process being based on considering the exterior condi tions around a so called periodontal pocket. This process comprises the steps: a) measuring the depth of the periodontal pocket, i.e. the distance between the bottom and the mouth of th pocket; b) measuring the temperature difference between the bottom, and mouth of the periodontal pocket; and c) determining the degree and development of the periodontitis in dependence of the parameters measu under step a) and step b) . In connection with the techniques according to the present invention it can be generally said that a temperature increase at the bottom of the periodontal pocket, more pre¬ cisely a temperature difference of more than about 0.5°C bet- ween the mouth and bottom of the periodontal pocket, consti¬ tutes an early sign of the fact that the periodontal process is entering an active stage. A temperature difference of more than about 1°C shows that the process is established. The present invention thus provides for reliable diagnostic tech- niques which are based on simultaneous measurement of the temperature difference between the bottom and the mouth of the pocket and the depth of the pocket, and through said techniques one may thus verify whether the periodontal pro¬ cess resides in an active stage and whether said process is established. The invention will in the following be further descri¬ bed by non-limiting examples in conjunction with the appended drawings, wherein: Fig. 1 shows diagramatically the construction of an apparatus according to the present invention with its auxili¬ ary equipment ; Fig. 2 shows diagramatically the measuring transducer with associated probe; Fig. 3 shows on a larger scale the distal probe part of the measuring transducer; Fig. 4 shows diagrammatically a scheme on another em¬ bodiment of the invention; Fig. 5 shows more in detail the display unit of the embodiment of Fig. 4; Fig. 6 shows a diagram on the development of periodon- titiβ over time as a function of the temperature difference between the bottom and the mouth of the periodontal pocket; and Fig. 7 shows a corresponding diagram including the result of hygiene treatment. EXAMPLE 1 Figure 1 shows diagramatically the structure of the instrument in the form of a block diagram. In principle, t instrument consists of a manually held measuring transduce 1, which via a cable is connected to a recording unit cons ting of an amplifier with filter 3, computer 5, display 7, rinter 9 and a device 11 for voltage supply. In the amplif ing unit 3 the amplification is adjusted in such /a manner that a suitable signal size is obtained to computer 5. Sai computer is of a conventional type and can be constituted example by a Zilog Z80 with associated operational circuit and programable memory. In this non-limiting example there has been chosen as a display 7 a liquid crystal display, s ce such device consume substantially less energy than a co responding display of the light emitting diod type. If, ho ever, the instrument is directly means-connected this latt type of better readability can advantageously be used. The voltage supply unit 11 may consist of a recharg le system with nickel-cadmium cells and associated charger However, the instrument may also be connected directly to mains . In both cases the voltage unit contains suitably ar ranged control circuits stabilizing the voltage through th other part of the electronic equipment. In Figs. 2 and 3 t manually held measuring probe 1 is shown more in detail. T measuring probe 1 in principle consists of a probe 13 atta ed to a handle 15 and the free distal end 17 which is show in enlargement in Fig. 3. This free end 17 is at its tip p vided with a temperature sensor or transducer 19 which through electrically leading cables 21 is connected with t recording unit of the instrument as described in connectio with Fig. 1. The free end 17 of the probe 13 is further pr vided with markings 23 enabling measurement of the depth o the periodontal pocket. According to Fig. 2 the measuring probe is provided with a switch for activating the instrument. The function of the instrument described is briefly the following. The measuring probe 1 is placed with the free end 17 of probe 13 placed n the periodontal pocket which is subject to diagnosis, sensor or transducer 19 being positioned adja¬ cent to the bottom of the pocket. The electronics are then activated by means of a switch 25. The temperature which is registered at the bottom of the periodontal pocket is measur¬ ed by the computer, and when the signal has been stabilized the level is recorded and the operator is correspondingly informed for example by a short sound signal. The measured value can then as the case may be be registered with printer 9. Then the measuring probe 13 with its free end 17 and sensor or transducer 19 is moved to the mouth of the perio¬ dontal pocket and the measuring procedure is repeated. By means of computer 7 the difference between the two tempera¬ tures measured is now calculated, said difference being show on the display 5 of the instrument and may also be registere by printer 9. In connection with measuring the temperature at the bottom of the periodontal pocket also the depth of said pock et is measured by means of the scale or marking 23. By correlating the temperature difference measured an the depth of the periodontal pocket information whether the periodontal process is moving into an active stage and wheth er the process is established will be obtained in a simple manner. In accordance with the result obtained a suitable treatment regime can then be instituted. EXAMPLE 2 The blockdiagram in Fig. 4 shows another preferred embodiment of the apparatus according to the present inven¬ tion. The temperature probe with its sensor 31 is connected via a cable to an electronic unit 32 consisting of an ampli¬ fier with filter, computer and power supply. The temperature probe has a build-m-actlvator for registration of eventual bleeding m the tooth pocket . The display 33 unit as shown i Fig. 5 is connected via a cable to the electronic unit. The display has two groups 40,41 of figures. One 40 for indica ¬ tion of the number of the tooth and another 41 for the dis¬ play of the temperature difference between the mouth of the periodontal pocket and the bottom. Furthermore, there is an array of indicators to show the position in the tooth pocket and a reset-switch 42 to be able to start the measurements from the beginning. The registgration of the temperature is activated by a footswitch 34. AB seen in Fig. 4 a remote display 35 and/or a printer 36 is also available to connect to the electronic unit. The measuring procedure is as follows: 1. Preβs the "reset" button. 2. The probe 31 is placed into the bottom of the tooth pocket . 3. Activate the footswitch 34. 4. When a low frequency signal is heard the measurement procedure is completed. 5. Move to the mouth of the tooth pocket. 6. Activate the footswitch. 7. When the measuring period is completed a high frequency signal is heard. B. The display shows the temperature difference and the indicator moves automatically to the next measuring site . Registration of bleeding can be performed for the measured position by activating the probe. An indication 43 will appear on the display. The advantage with this embodiment is that the probe could be held more firm since the measurement is activated by the footswitch. EXAMPLE 3 Example of registration correlated to the development of per¬ iodontitis Fig. 6 shows registrations of the initial temperature difference between the bottom and the mouth (t^) of 30 perio¬ dontal pocket at the initial stage 30 periodontal pockets distributed among 4 patients and the subsequent change in anchorage of the tooth at the respective periodontal pocket measured after five months (a-j). The teeth around which the registrations have been made have all diagnosed periodon¬ titis. A positive value of a- j means that the attachment has increased, whereas a negative value means loss of attachment, i.e. the periodontitis has progressed. Values of t<-ι<0.5 o C in the initial stage are seen only for periodontal pockets where a gain or no change of the attachment of the tooth has been registered. Average a^ in the range is 0.46mm, i.e. a gain of attachment. Values of t c j>.0.5 o C but <1.0°C have often resulted in a loss of tooth attachment. Average f^ in said range is -1.00mm. The most serious losses of tooth attachment are seen for t^l • 0°C having an average a- j in the range of -2.75mm, i.e. the periodontitis has developed. EXAMPLE 4 Fig. 7 shows registrations of the initial temperature difference between the bottom and the mouth of 35 periodontal pockets (t jj distributed among 6 patients and the subsequent change in anchorage of the tooth at the respective peridontal pocket (a,- } , measured after 2 months. Only periodontal pockets with a temperature difference of more than 0.5°C (t cj >0.5 o C) were selected. After registration of t<- j , they were given hygiene treatment with subgingival scaling. After 2 months change in periodontal anchorage was registered (a- j ) . By the treatment these periodontal pockets, which would have lost periodontal attachement according to Example 3 because of active periodontitis as indicated by t,- j >0.5 o C instead gained or maintained their original level of anchorage, as an average a cj =0.77 mm.

Claims: CLAI MS 1. Apparatus for diagnosing an inflammatory conditio relating to periodon itiB , comprising means (1,3) for measu ing and recording temperature in connection with a periodon 5 ta pocket, characterized by measuring means (17) with a gr duated scale (21) for measuring the depth of the periodonta pocket and in association herewith also provided with means (5) for measuring and recording the temperature difference between the bottom and the mouth of the periodontal pocket. 10 2. Apparatus according to claim 1, characterized in that said means for temperature measurement is constituted a probe (15) which is connected to the measuring means (17) in such a manner that the depth of the periodontal pocket c be recorded in connection with measuring the temperature at 15 its bottom. 3. Apparatus according to claim 1 or 2, characterize in that the probe (15) comprises a sensor or transducer of the type thermoelement, thermistor, semiconductor diode or resistance transducer. 20 4. Apparatus according to any preceding claim, chara terized in that the probe (15) and the measuring means are assembled into one un.it. 5. Apparatus for diagnosing an inflammatory conditio related to periodontitis, comprising means (1,3) for measu- 25 ring and recording temperature in connection with a periodo tal pocket, characterized in that said means for temperatur measurement comprises a probe having two sensors or trans¬ ducers movable relative to each other, and characterized by measuring means having a graduated scale for measuring the 30 depth of the peridontal pocket, one sensor or transducer of the probe being permanently connected to the measuring mean at its free end, whereas the other sensor or transmitter is movable along the scale so that the temperature difference between the bottom and the mouth of the periodontal pocket 35 can be recorded at the same time as the pocket depth is mea sured. 6. Apparatus according to claim 5, characterized in that the probe comprises two sensors or transducers of the type thermoelement, thermistor, semiconductor diode or resis tance transducer. 7. A process for diagnosing an inflammatory condition related to periodontitis based on considering the exterior conditions around a so called periodontal pocket, characteri zed by the steps: a) measuring the depth of the periodontal pocket, i.e. the distance between the bottom and the mouth of the pocket; b) measuring the temperature difference between the bottom and the mouth of the periodontal pocket; and c) determining the degree and development of the periodontitis in dependence of the parameters measure under step a) and step b) .

Inventors: BLOMLOEF LEIF, LINDSKOG SVEN, BLOMLOEF, LEIF, LINDSKOG, SVEN
Applicants: BIOAPATITE AB, BIORA AB
Application year: 1991
Main classification: A61B5
IPC codes: A61B5, A61C19