Patent Publication Number: US-2022214302-A1

Title: Detection apparatus and data collection method

Description:
TECHNICAL FIELD 
     The present invention relates to a detection apparatus and a data collection method. 
     BACKGROUND ART 
     There is a demand for detecting abnormalities related to bacteria attached to various objects. 
     Here, a dental implant treatment is a treatment method for joining an artificial tooth to which the functions and form of a tooth are imparted on a fixture that is an artificial tooth root embedded in the jawbone. 
     The artificial tooth may be directly coupled to the fixture (one-piece type) or may be fixed to an abutment (abutment portion) fixed to the fixture (two-piece type). 
     Since dental implants are stored in the oral cavity and used for a long period of time, it is known that bacteria attached between the dental implant and the gums are activated and/or proliferate depending on an environment in the oral cavity, thereby causing pen-implant mucositis. 
     As a dental implant for preventing such a disease caused by bacteria, Patent Literature 1 describes “a dental implant (118) or an element thereof comprising a transmucosal portion (122), wherein at least a part of the transmucosal portion (122) includes a biocide (132) and/or a pH adjuster”. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: JP 2017-511241 A 
     SUMMARY OF INVENTION 
     Technical Problem 
     In order to prevent inflammation caused by bacteria occurring around the dental implant, a method in which a dentist diagnoses a state of a tissue around the implant (for example, examination of a probing depth, observation of bleeding at the time of probing, confirmation of presence or absence of drainage, and the like) is often adopted in a periodic examination by the dentist. 
     However, according to the above method, although it is possible to detect a state in which inflammation has already occurred, there is a problem that it is not possible to detect a situation before inflammation occurs, specifically, a situation in which the activity of bacteria improves or bacteria starts to proliferate. Note that the problems of abnormalities related to bacteria may occur not only in dental implants but also in various objects. 
     Therefore, an object of the present invention is to provide an apparatus capable of easily obtaining information for determining presence or absence of an abnormality related to bacteria attached to an object. In addition, another object of the present invention is to provide a data collection method. 
     Solution to Problem 
     As a result of intensive studies to achieve the above objects, the present inventor have found that the above objects can be achieved by the following configurations. 
     [1] A detection apparatus including an electrode formation unit that is brought into contact with an object to form an electrode, a detection unit that constitutes an electrode pair with the electrode; a measurement unit that measures a current flowing between the electrode and the detection unit, and a determination unit that determines presence or absence of an abnormality related to bacteria attached to the object according to the current measured by the measurement unit.
 
[2] The detection apparatus according to [1], in which the object is a dental implant.
 
[3] The detection apparatus according to [1] or [2], in which the detection unit further includes an electron source emission unit capable of emitting an electron source.
 
[4] The detection apparatus according to any one of [1] to [3], further including a reference electrode.
 
[5] The detection apparatus according to any one of [1] to [4], in which the determination unit includes a comparison unit that compares the current with a predetermined reference, and an abnormality detection unit that detects the abnormality on the basis of a result of the comparison, and the abnormality detection unit prompts to display attention calling information in a case where the abnormality detection unit detects the abnormality.
 
[6] The apparatus according to [5], in which the attention calling information is information for informing that bacteria may be proliferating.
 
[7] A data collection method including a step of forming an electrode by bringing an electrical conductor into contact with an object in contact with an electrolytic solution, a step of forming an electrode pair by bringing an electrode different from the electrode into contact with the electrolytic solution, the electrode pair being arranged apart from each other via the electrolytic solution, and a step of measuring a current flowing between the electrode pair.
 
     Advantageous Effects of Invention 
     According to the present invention, it is possible to provide an apparatus capable of easily obtaining information for evaluating the activity of bacteria around a dental implant. In addition, the present invention can also provide a data collection method. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram of a detection apparatus according to a first embodiment of the present invention. 
         FIG. 2  is a hardware configuration diagram of the detection apparatus according to the first embodiment of the present invention. 
         FIG. 3  is a schematic diagram illustrating a usage aspect of the detection apparatus according to the first embodiment of the present invention. 
         FIG. 4  is a graph illustrating experimental results by the inventor of the present invention. 
         FIG. 5  is a schematic diagram illustrating a method of detecting occurrence of an abnormality by the detection apparatus and specifying an abnormality occurrence position according to the first embodiment of the present invention. 
         FIG. 6  is a flowchart of a data collection method according to the first embodiment of the present invention. 
         FIG. 7  is a schematic diagram illustrating a usage aspect of a detection apparatus according to a second embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
     [Detection Apparatus] 
     A detection apparatus  10  according to a first embodiment of the present invention will be described with reference to the drawings. 
     The detection apparatus  10  detects an abnormality related to bacteria attached to a dental implant (exemplifying an object). The abnormality related to bacteria is, for example, activation of bacteria or proliferation of bacteria or the like. 
       FIG. 1  is a block diagram of the detection apparatus  10 ,  FIG. 2  is a hardware configuration diagram of the detection apparatus  10 , and  FIG. 3  is a schematic diagram of the detection apparatus  10 . 
     The detection apparatus  10  illustrated in  FIG. 1  includes an electrode formation unit  11 , a detection unit  12 , a measurement unit  13 , an adjustment unit  14 , a comparison unit  15 , an abnormality detection unit  16 , an electron source emission unit  17 , a control unit  18 , and an input/output device including a display device  19   a  and an input device  19   b.    
     Among those units and devices, the control unit  18  includes a central processing unit  18   a  and a storage device  18   b , and the comparison unit  15  and the abnormality detection unit  16  correspond to a program stored in the storage device  18   b  and to the central processing unit  18   a . In addition, the adjustment unit  14  and the measurement unit  13  are controlled by the control unit  18 , and the detection unit  12 , the electron source emission unit  17 , which is constituted integrally with the detection unit  12 , and the electrode formation unit  11  are controlled by the control unit  18  via the adjustment unit  14  and the measurement unit  13 . 
     As illustrated in  FIG. 2 , in the detection apparatus  10 , the electrode formation unit  11  and a dental implant Imp are brought into contact with each other to form one electrode (working electrode WE). That is, the electrode formation unit  11  forms the working electrode WE by coming into contact with the dental implant Imp. In the present specification, the “dental implant” means a one-piece type fixture and abutment and a two-piece type fixture and abutment and usually includes a conductive material such as titanium or a titanium alloy. 
     The dental implant Imp is usually arranged in the oral cavity, and the periphery thereof is wetted with an electrolytic solution such as saliva. 
     The detection unit  12  constitutes an electrode (counter electrode CE) paired with the working electrode WE, and the working electrode WE and the counter electrode CE are arranged apart from each other via the electrolytic solution. 
     The electrode formation unit  11  and the detection unit  12  are electrically connected via the measurement unit  13 , and the measurement unit  13  can measure a current flowing between the working electrode WE and the counter electrode CE. 
     The present inventor has conducted intensive studies to electrochemically detect the activity of bacteria in the oral cavity. As a result, it has been found that bacteria transfer electrons to an extracellular solid (electron conductor), thereby obtaining energy in a state in which the bacteria can exert pathogenicity. Note that becoming a state in which pathogenicity can be exhibited means, for example, becoming a state in which a biofilm is formed as a result of activation or proliferation of bacteria (that is, occurrence of an abnormality related to bacteria) and a state in which the biofilm is acidified. Note that the biofilm is a membrane formed by attachment of bacteria to a surface. 
     Specifically, regarding  Streptococcus mutans  bacteria cultured under acidic conditions (pH 4) and  Streptococcus mutans  bacteria cultured under neutral conditions, the present inventor observed sections stained specifically for oxidation-reduction reaction with a transmission electron microscope and found that the surface of a cell wall and an inner cell membrane are specifically stained in a case where the  Streptococcus mutans  bacteria are cultured under acidic conditions. 
     In addition, it has also been confirmed that  Capnocytophaga ochracea  bacteria, which are also known as causative bacteria of periodontal diseases, specifically express electron transfer enzymes in an anaerobic environment. 
     The above illustrates that biofilm formation, metabolism in the biofilm, and acidification of the biofilm and occurrence of a current (electron transfer to the extracellular solid) have a close relationship each other. 
     The present inventor conducted an experiment to examine electron transfer in the intraoral bacteria that are  Streptococcus mutans  ( S. mutans ) under acidic conditions.  FIG. 4  is a graph illustrating experimental results (temporal changes in a current) regarding electron transfer in the intraoral bacteria. Note that the current was measured by an anaerobic reactor device including three electrodes (reference electrode, working electrode, and indium tin oxide (ITO) electrode). The current was measured in the presence of the intraoral bacteria in the presence of 10 mM glucose (electron source). Note that intraoral bacteria cultured in an acidic unbuffered solution (pH 4.6±0.2) were used. Specifically, each electrode was arranged in a culture solution of the intraoral bacteria in which 10 mM glucose was present, and a current flowing between the working electrode and the ITO electrode when an electric potential was applied was measured. 
     As can be grasped from  FIG. 4 , it has been found that a detected current increases with time. That is, it can be said that electron transfer in the intraoral bacteria become active with the lapse of time. A state in which electron transfer become active is considered to be a state in which a biofilm is formed on the surface of the electrode and the intraoral bacteria are activated and proliferating. Note that, it is considered that a current value correlates with the number of the intraoral bacteria. Utilizing the above findings, the detection apparatus  10  of the present invention employs a configuration in which an abnormality related to bacteria is detected according to a change in a current flowing between electrodes. 
     Note that in  FIG. 4 , the temporal changes in the current are detected over several hours, but a time length for detecting temporal changes in the current is any length. For example, in the detection apparatus  10  of the present invention, a temporal change in the current may be detected for a very short time length (for example, for several seconds). 
     As understood from the above description, in a case where there is an abnormality related to bacteria around the dental implant (for example, in a case where the bacteria are activated and/or proliferating), it is presumed that the bacteria obtain energy by transferring surplus electrons to the dental implant that is an extracellular solid. 
     In the detection apparatus  10 , the dental implant Imp is formed as one electrode and is connected to the counter electrode CE (detection unit  12 ) via the measurement unit  13 . Therefore, the detection of the current value in the detection apparatus  10  means a state in which electron transfer from the bacteria to the dental implant Imp has occurred, that is, a state in which the bacteria can exert pathogenicity (for example, a state in which a biofilm is formed and a state in which the biofilm is acidified). Eventually, it is a state in which an abnormality related to the bacteria attached to the dental implant Imp has occurred. As understood from the above description, it can also be said that the current flowing between the electrode pair reflects an activity situation of the bacteria present around the working electrode WE and the counter electrode CE (for example, a situation of activation of the bacteria or a situation of proliferation of the bacteria). 
     By scanning over the dental implant Imp with the detection unit  12  and observing a change in the current value during the scan, it is possible to specify a place where the above-described abnormality has occurred (abnormality occurrence position). 
     Conventionally, it is general that as for inflammation caused by bacteria occurring between a dental implant and the gums, it is confirmed visually that inflammation had occurred and then the inflammation is addressed. In contrast, by using the detection apparatus  10 , the abnormality occurrence position can be easily and quickly specified, and the abnormality can also be detected at a stage before visible inflammation occurs. 
     In addition, the detection apparatus  10  includes the adjustment unit  14 . The adjustment unit  14  applies an electric potential between the working electrode WE formed by the electrode formation unit  11  and the counter electrode CE that is the detection unit  12 . Since the detection apparatus  10  includes the adjustment unit  14 , even in a case where the number of cells of the bacteria is small, a more excellent response speed can be obtained by applying an electric potential between both electrodes. The form of the adjustment unit  14  is not particularly limited, but typically, a potentio/galvanostat (P/G stat, illustrated a symbol “PGST” in  FIG. 2 ) including the measurement unit  13  and the adjustment unit  14  can be used. 
     Note that the detection apparatus  10  includes the adjustment unit  14 , but the detection apparatus  10  according to the first embodiment of the present invention may not include the adjustment unit  14 . In a state in which the bacteria exhibit pathogenicity, it is presumed that the bacteria transfer electrons to the dental implant Imp that is an extracellular solid (electrical conductor) to obtain energy. That is, in a case where the bacteria exhibit pathogenicity, it is possible to detect a current without applying an electric potential if a connection to the counter electrode CE and the dental implant Imp is made to form a circuit. 
     In  FIG. 3 , the dental implant Imp is embedded in a jawbone  33 , and an artificial tooth  30  is fixed to a tip portion. A part of the dental implant Imp is exposed from gums  32 . The electrode formation unit  11  is brought in contact with the dental implant Imp at an exposed portion Pos 1 , and the electrode formation unit  11  and the dental implant Imp constitute the working electrode WE. 
     Meanwhile, the detection unit  12  includes an electrode  34  and the electron source emission unit  17 . The electron source emission unit  17  includes a nozzle  17   a  for emitting an electron source (typically, an aqueous solution containing an electron source), an electron source storage unit  17   c  communicating with the nozzle  17   a  via a pipe, and a pump  17   b  arranged in the pipe, and the electron source emission unit  17  is configured so that a predetermined amount of the electron source is emitted by operating the pump  17   b  controlled by the control unit  18 . 
     The electrode  34  is arranged so as to come in contact with an electrolytic solution  31  (typically saliva) present around the dental implant Imp and is arranged with the working electrode WE via the electrolytic solution  31  to function as the counter electrode CE. Each of the electrodes is electrically connected by the potentio/galvano (P/G) stat PGST, and a current flowing between both electrodes can be measured. 
     The electron source emitted from the electron source emission unit  17  is not particularly limited, and examples thereof include glucose, lactic acid, and the like. The electron source emission unit  17  may emit the electron source itself and may emit a solution containing the electron source. Typically, an aqueous solution containing the electron source can be used, and examples thereof include physiological saline containing the electron source and the like. 
       FIG. 5  is a schematic diagram illustrating a method of detecting the occurrence of the abnormality by the detection apparatus  10  and specifying the abnormality occurrence position. In  FIG. 5 , a fine biofilm  42  is formed on the dental implant Imp, and the bacteria are activated. 
       FIG. 5( a )  schematically illustrates a response detected by the measurement unit  13  with a horizontal axis representing observation time and a vertical axis representing a current. A broken line illustrates a response in a case where there is no abnormality (in a case where there is no electron transfer), and a solid line illustrates a response in a case where there is an abnormality (in a case where there is electron transfer). 
     The biofilm  42  is formed on the dental implant Imp, and electron transfer from the bacteria to the dental implant Imp occurs. According to the detection apparatus  10 , the occurrence of the abnormality can be detected by detecting a current caused by the electron transfer. 
     In addition, since the detection apparatus  10  includes the detection unit  12  formed by integrating the electrode  34  and the electron source emission unit  17  (nozzle  17   a ), it is possible to specify the abnormality occurrence position by scanning over the dental implant Imp with the detection unit  12 . 
     A scan is performed from a position illustrated by (A) to a position illustrated by (B) in  FIG. 5  with the detection unit  12 . At this time, a response measured at the position of (A) is defined as (a), and a response measured at the position of (B) is defined as (b). 
     First, at the position of (A), an electron source  41  emitted from the nozzle  17   a  is more likely to reach the bacteria in the biofilm  42 , at the position of (A), and thus, as illustrated in (a), the detected current increases after emission inj of the electron source  41 . 
     Meanwhile, at the position of (B), the electron source  41  emitted from the nozzle  17   a  is less likely to reach the biofilm  42  due to the bacteria in the biofilm and thus the current increases more gradually or does not increase. 
     That is, by examining a response while scanning with the detection unit  12 , it can be specified that the electron source is consumed and the current value increases, that is, the activity of the bacteria increases in a portion where a larger current is obtained as compared with the surroundings. 
     Since the detection apparatus  10  includes the electron source emission unit  17 , the detection apparatus  10  can detect a smaller amount of the bacteria and has a wider dynamic range and/or has a faster response speed. 
     Note that the detection apparatus  10  includes the electron source emission unit  17 , but the detection apparatus  10  according to the first embodiment of the present invention is not limited to the above and may not include the electron source emission unit  17 . 
     In the detection apparatus  10  of  FIG. 3 , the electron source emission unit  17  includes the nozzle  17   a  for emitting the electron source (typically, an aqueous solution containing an electron source), the electron source storage unit  17   c  communicating with the nozzle  17   a  via a pipe, and the pump  17   b  arranged in the pipe, and the electron source emission unit  17  is configured so that a predetermined amount of the electron source is emitted by operating the pump  17   b  controlled by the control unit  18 . 
     Note that in the detection apparatus  10 , the detection unit  12  and the electron source emission unit  17  are integrally formed, and the electron source emitted from the electron source emission unit  17  can be more efficiently arranged between the detection unit  12  and the dental implant Imp. 
     Note that the detection apparatus  10  according to the first embodiment of the present invention is not limited to the above, and the detection unit  12  and the electron source emission unit  17  may be arranged separately. 
     In addition, in the detection apparatus  10 , an amount of the electron source emitted by the electron source emission unit  17  and a timing when the electron source is emitted by the electron source emission unit  17  are controlled by the control unit  18 , but the detection apparatus  10  according to the first embodiment of the present invention is not limited to the above, and the operation and stop of the pump  17   b  may be controlled by an operator. 
     The measurement unit  13  measures the current between the working electrode WE and the counter electrode CE. When the current is measured, a measurement ID is generated by the measurement unit  13 , and data on time from the start of the measurement and a current value obtained at corresponding observation time is generated and stored for each measurement ID in an area secured in the storage device  18   b.    
     The data generated by the measurement unit  13  is passed to the comparison unit  15 . The comparison unit  15  compares the data generated by the measurement unit  13  with a predetermined reference (hereinafter referred to as a “reference threshold”). For example, the comparison unit  15  extracts data on the current value at a predetermined observation time and compares the extracted data with the reference threshold. Specifically, the comparison unit  15  compares whether the extracted data exceeds the reference threshold. 
     A result of the comparison is passed to the abnormality detection unit  16 . The abnormality detection unit  16  detects an abnormality related to the bacteria attached to the dental implant Imp on the basis of the result of the comparison by the comparison unit  15 . Specifically, in a case where the comparison unit  15  determines that the extracted data exceeds the reference threshold, the abnormality detection unit  16  determines that there is an abnormality related to the bacteria attached to the dental implant Imp. Then, the abnormality detection unit  16  prompts the display device  19   a  to display the measurement result, and the process ends. 
     Meanwhile, in a case where the comparison unit  15  determines that the extracted data is less than the reference threshold, the abnormality detection unit  16  determines that there is no abnormality related to the bacteria attached to the dental implant Imp. 
     As understood from the above description, the comparison unit  15  and the abnormality detection unit  16  function as a “determination unit” for determining the presence or absence of an abnormality related to the bacteria attached to the dental implant Imp according to the current measured by the measurement unit  13 . Note that it is not essential for the abnormality detection unit  16  to prompt the display device  19   a  to display the measurement result. 
     Note that in  FIG. 3 , the display device  19   a  and the input device  19   b , and the P/G stat PGST including the measurement unit  13  and the adjustment unit  14  are constituted separately but may be constituted integrally. 
     In addition, although the detection apparatus  10  includes the display device  19   a  and the input device  19   b , the detection apparatus  10  according to the first embodiment of the present invention may not include the display device  19   a  and the input device  19   b . In that case, a tablet terminal or the like that can wirelessly communicate with the detection apparatus  10  can also be used as a display device and an input device. 
     In addition, in a case where as a result of the comparison by the comparison unit  15 , the extracted data does not satisfy a reference, the abnormality detection unit  16  prompts the display device  19   a  to display attention calling information. The attention calling information typically means that the activity of the bacteria improves or the bacteria may be proliferating on an implant surface, more specifically, on a measurement target site (position of the detection unit  12 ). By performing this operation while scanning over the dental implant Imp with the detection unit  12 , it is possible to specify the abnormality occurrence position on the dental implant Imp. 
     Since in the detection apparatus  10 , the dental implant Imp serves as one electrode, and the detection unit  12  serves as the other electrode, it is possible to easily obtain information for evaluating the activity of the bacteria in a narrow range around the detection unit  12 . Even for the same tooth, it is possible to easily obtain information for evaluating the activity of the bacteria in a narrow range by dividing the tooth into sites on a buccal side (lip side), a palate side (tongue side), and the like. 
     Note that the detection apparatus  10  may further include a reference electrode. In a case where the detection apparatus  10  includes the reference electrode, an electrode potential can be measured. In a case where the detection apparatus  10  includes the reference electrode, the detection apparatus  10  may be arranged independently from the electrode formation unit  11  and the detection unit  12  or may be arranged integrally with the electrode formation unit  11  and/or the detection unit  12 . In particular, it is preferable that the detection unit  12  and the reference electrode are constituted integrally from the viewpoint of easier handling. 
     [Data Collection Method] 
     A data collection method of the present invention is a data collection method including a step of forming an electrode by bringing an electrical conductor into contact with a dental implant in contact with an electrolytic solution, a step of forming an electrode pair by bringing an electrode different from the electrode into contact with the electrolytic solution, the electrode pair being arranged apart from each other via the electrolytic solution, and a step of measuring a current flowing between the electrode pair.  FIG. 6  is a flowchart of the data collection method. 
     First, an electrical conductor is brought into contact with a dental implant in contact with an electrolytic solution to form an electrode (S 1 ). The electrical conductor is not particularly limited, and examples thereof include carbon, gold, platinum, silver, molybdenum, cobalt, nickel, palladium, ruthenium, and the like, and the electrical conductor may be indium tin oxide or the like. In addition, a shape and the like are not particularly limited, but the shape is preferably a probe shape or a wire shape from the viewpoint of easier contact with the dental implant. 
     Next, an electrode different from the electrode is brought into contact with the electrolytic solution (S 2 ). Here, the electrolytic solution is typically preferably saliva around the dental implant or the like and may be a mixture of an aqueous solution containing an electron source (for example, physiological saline containing glucose) and saliva. 
     A material of the electrode is not particularly limited, and the materials exemplified above as the electrical conductor can be used. In addition, a shape and the like are not particularly limited, but the shape is preferably a probe shape or a wire shape the viewpoint of easier contact with the dental implant. 
     An electrode pair is formed as described above, and then a current flowing between the electrode pair is measured (S 3 ). The current reflects the activity of pathogenic microorganisms around the dental implant. Thus, data collected using the above data collection method (current measured at S 3 ) can be used to evaluate the activity of pathogenic microorganisms around the dental implant. 
     Second Embodiment 
     A second embodiment of the present invention will be described. Note that elements having actions or functions similar to those of the first embodiment in embodiments exemplified below will be appropriately omitted from detailed description by using reference signs used in the description of the first embodiment. 
       FIG. 7  is a schematic diagram illustrating a usage aspect of a detection apparatus  10  according to the second embodiment. In  FIG. 7 , only an electrode formation unit  11  and a detection unit  12  in the detection apparatus  10  are illustrated for convenience. In the first embodiment, an abnormality related to the bacteria attached to the dental implant is detected, but in the second embodiment, an abnormality related to bacteria attached to an endoscope  50  (exemplifying an object) is detected. Note that a configuration of the detection apparatus  10  is similar to that of the first embodiment. 
     The endoscope  50  is a medical device for observing the inside of the human body (for example, the gastrointestinal tract and the large intestine). Specifically, the endoscope  50  includes an insertion unit  51  and an operation unit  52 . The insertion unit  51  is a portion to be inserted into the human body. An imaging element C capable of imaging the inside of the human body is mounted at a distal end of the insertion unit  51 . The operation unit  52  is an operator operated by an operator (typically, a doctor). 
     In the second embodiment, an abnormality related to the bacteria attached to the insertion unit  51  of the endoscope  50  is detected. The electrode formation unit  11  is in contact with the insertion unit  51 , and the electrode formation unit  11  and the insertion unit  51  constitutes a working electrode WE. In addition, the detection unit  12  constitutes an electrode (counter electrode CE) paired with the working electrode WE. Then, as in the first embodiment, the working electrode WE and the counter electrode CE are arranged apart from each other via an electrolytic solution. Note that in the second embodiment, for example, physiological saline is used as the electrolytic solution. 
     In the detection apparatus  10  of the second embodiment, a scan over the insertion unit  51  is performed with the detection unit  12 , and a change in a current value during the scan is observed as in the first embodiment. As in the first embodiment, in a state in which the bacteria exhibit pathogenicity, the bacteria transfer electrons to the insertion unit  51  that is an extracellular solid (electrical conductor). Therefore, a current is detected by a measurement unit  13 . 
     As in the first embodiment, the measurement unit  13  measures a current between the working electrode WE and the counter electrode CE. As in the first embodiment, the comparison unit  15  compares data on the current value measured by the measurement unit  13  with a reference threshold. Then, as in the first embodiment, an abnormality detection unit  16  detects an abnormality related to bacteria attached to the insertion unit  51  on the basis of a result of the comparison by the comparison unit  15 . 
     Also in the second embodiment, effects similar to the effects of the first embodiment are achieved. In addition, since the endoscope  50  is inserted into the human body, an abnormality particularly related to bacteria becomes a problem. For example, when the endoscope  50  is inserted into the human body in a state in which the bacteria attached to the insertion unit  51  are activated or proliferate, an infection or the like may occur. According to the detection apparatus  10  of the second embodiment, it is possible to easily and quickly detect the abnormality related to bacteria attached to the endoscope  50 . 
     Note that in  FIG. 7 , a configuration for detecting an abnormality related to bacteria attached to the surface of the insertion unit  51  has been exemplified, but a portion for detecting an abnormality related to bacteria in the endoscope  50  is not limited to the above example. For example, an abnormality related to bacteria in the operation unit  52  may be detected. 
     In addition, an object to be detected for an abnormality related to bacteria is not limited to the dental implant and the endoscope. Various articles capable of functioning as electrodes are exemplified as the object. For example, various medical instruments such as surgical instruments (for example, scalpels and forceps) and cannulas are exemplified as the object. Note that in a case where a tubular article such as a cannula is used as the object, it is also possible to detect an abnormality related to bacteria attached to the inside of a tube by inserting the detection unit  12  into the tube. In addition, various devices used in food factories, factories manufacturing precision devices, and the like may be used as the object. As understood from the above description, various objects in which occurrence of bacteria is a problem are targets for detecting an abnormality related to bacteria in the detection apparatus of the present application. 
     INDUSTRIAL APPLICABILITY 
     Bacteria attached to various objects cause various problems in terms of hygiene and health. For example, conventionally, it is general that, as for inflammation caused by bacteria occurring between a dental implant and the gums, it is confirmed visually that inflammation had occurred and then the inflammation is addressed. In contrast, by using the detection apparatus according to the present invention, it is possible to perform measurement easily and quickly, and it is possible to detect before the occurrence of visible inflammation, more specifically, to detect, on the basis of a current, a situation in which the activity of bacteria increases. 
     In addition, for example, since bacteria attached to the endoscope can cause an infection or the like, it is particularly important to detect an abnormality related to the bacteria attached to the endoscope. With the detection apparatus according to the present invention, it is possible to reliably detect an abnormality related to bacteria with an configuration for easy and quick measuring a current between electrodes. 
     REFERENCE SIGNS LIST 
     
         
           10  Detection apparatus 
           11  Electrode formation unit 
           12  Detection Unit 
           13  Measurement unit 
           14  Adjustment unit 
           15  Comparison unit 
           16  Abnormality detection unit 
           17  Electron source emission unit 
           17   a  Nozzle 
           17   b  Pump 
           17   c  Electron source storage unit 
           18  Control unit 
           18   a  Central processing unit 
           18   b  Storage device 
           19   a  Display device 
           19   b  Input device 
           30  Artificial tooth 
           31  Electrolytic solution 
           32  Gums 
           33  Jawbone 
           34  Electrode 
           41  Electron source 
           42  Biofilm 
           50  Endoscope 
           51  Insertion unit 
           52  Operation unit