Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C19/00—Dental auxiliary appliances
  • A61C19/06—Implements for therapeutic treatment
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M37/00—Other apparatus for introducing media into the body; Percutany, i.e. introducing medicines into the body by diffusion through the skin
  • A61M37/0092—Other apparatus for introducing media into the body; Percutany, i.e. introducing medicines into the body by diffusion through the skin using ultrasonic, sonic or infrasonic vibrations, e.g. phonophoresis
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C1/00—Dental machines for boring or cutting ; General features of dental machines or apparatus, e.g. hand-piece design
  • A61C1/0007—Control devices or systems
  • A61C1/0015—Electrical systems
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K33/00—Medicinal preparations containing inorganic active ingredients
  • A61K33/42—Phosphorus; Compounds thereof
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
  • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
  • A61K47/51—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent
  • A61K47/62—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being a protein, peptide or polyamino acid
  • A61K47/64—Drug-peptide, drug-protein or drug-polyamino acid conjugates, i.e. the modifying agent being a peptide, protein or polyamino acid which is covalently bonded or complexed to a therapeutically active agent
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/20—Applying electric currents by contact electrodes continuous direct currents
  • A61N1/30—Apparatus for iontophoresis, i.e. transfer of media in ionic state by an electromotoric force into the body, or cataphoresis
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/20—Applying electric currents by contact electrodes continuous direct currents
  • A61N1/30—Apparatus for iontophoresis, i.e. transfer of media in ionic state by an electromotoric force into the body, or cataphoresis
  • A61N1/303—Constructional details
  • A61N1/306—Arrangements where at least part of the apparatus is introduced into the body
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
  • A61N1/325—Applying electric currents by contact electrodes alternating or intermittent currents for iontophoresis, i.e. transfer of media in ionic state by an electromotoric force into the body
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B25/00—Phosphorus; Compounds thereof
  • C01B25/16—Oxyacids of phosphorus; Salts thereof
  • C01B25/26—Phosphates
  • C01B25/32—Phosphates of magnesium, calcium, strontium, or barium
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B25/00—Phosphorus; Compounds thereof
  • C01B25/16—Oxyacids of phosphorus; Salts thereof
  • C01B25/26—Phosphates
  • C01B25/455—Phosphates containing halogen
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07K—PEPTIDES
  • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
  • C07K14/435—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
  • C07K14/46—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans from vertebrates
  • C07K14/47—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans from vertebrates from mammals
  • C07K14/4701—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans from vertebrates from mammals not used
  • C07K14/4732—Casein
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K9/00—Medicinal preparations characterised by special physical form
  • A61K9/0002—Galenical forms characterised by the drug release technique; Application systems commanded by energy
  • A61K9/0009—Galenical forms characterised by the drug release technique; Application systems commanded by energy involving or responsive to electricity, magnetism or acoustic waves; Galenical aspects of sonophoresis, iontophoresis, electroporation or electroosmosis

Definitions

• the present invention relates to an apparatus and method for mineralising biological material and in particular for re-mineralising demineralised and hypo-mineralised tissue, such as tooth or bone.
• Caries is the decay of tooth or bone.
• Dental caries also known as dental decay, caries or carious lesions
• the acids decalcify (demineralise) the inorganic portion of the tooth initially creating a sub-surface lesion, the organic portion then disintegrates leading to the creation of a cavity.
• demineralisation of a tooth through the development of a carious lesion can be described in terms of the depth of the carious lesion.
• Dental caries is commonly treated by the removal of the decayed material in the tooth and the filling of the resultant hole (cavity) with a dental amalgam or other restorative material. In more severe cases, the entire tooth may be removed. Prior to lesion cavitation, it is possible to heal or reverse the tissue destruction by remineralising the caries lesions. However, this process works better where exogenous (e.g. salivary- or food-derived) proteins and lipids have been removed from the caries lesions.
• exogenous e.g. salivary- or food-derived
• the impedance (which includes the DC resistance) can be monitored by using AC signals.
• Iontophoresis is a non-invasive method of propelling a charged substance, normally a medication or a bioactive agent, using an electric current. It is known to use iontophoresis in transdermal drug delivery. Iontophoresis may also be used in conjunction with fluoride containing compounds to treat dentine hypersensitivity and to remineralise non-cavitated dental caries lesions. Iontophoresis devices typically include an active electrode assembly and a counter electrode assembly each coupled to opposite poles or terminals of a voltage source. The active agent can be cationic or anionic and the voltage source can be configured to apply the appropriate voltage polarity based upon the polarity of the active agent.
• the active agent may be stored in for example, a reservoir such as a cavity or in a porous structure or a gel.
• Ultrasound is a longitudinal pulse.
• ultrasound is known generally for cleaning, e.g. removal of calculus from the external surface of teeth or debris from the pulp chamber and root canal inside a tooth during root canal treatment.
• Electrosonophoresis is a combination of iontophoresis and ultrasound.
• apparatus for mineralising a biological material comprising an ultrasonic source, operable to generate an ultrasonic signal, an ultrasonic probe and one or more mineralising probes, operable to receive a mineralising agent, wherein the mineralising agent is transferred from at least one mineralising probe to the biological material using the ultrasonic signal.
• At least one mineralising probe may be the ultrasonic probe.
• the apparatus comprises an iontophoresis probe.
• the apparatus of the present invention may utilise electrosonophoresis.
• the apparatus advantageously further comprises a first electrode and a second electrode and an electrical signal generator, operable to generate an electrical signal between the first and second electrodes, a detector, operable to detect the electrical response of the electrical signal between the first and second electrodes, and a controller operable to receive the detected electrical response and to control the ultrasonic signal relative thereto.
• the apparatus advantageously further comprises a mineralising probe electrode and a modulator, operable to modulate the electrical signal between the mineralising probe electrode and the second electrode and thereby cause the transfer of mineralising agent to the biological material using the electrical signal.
• the mineralising probe electrode is the first electrode.
• the controller is preferably operable to control modulation of the electrical signal relative to the detected electrical response.
• the apparatus advantageously further comprises a reference electrode operable to control at least one of the modulation of the electrical signal and the ultrasonic signal.
• the controller advantageously comprises a first software module having a dataset which describes the characteristic electrical response of a sample biological material at various stages of mineralisation, and a second software module which compares said data with the detected electrical response and thereby determine any required modification of at least one of the electrical signal and ultrasonic signal.
• the second software module may apply a function which defines the relationship between mineralisation and the electrical response in order to compare said data with the detected electrical response and to thereby determine any required modification of at least one of the electrical signal and ultrasonic signal.
• the second software module may apply a look-up table containing information on the electrical response of the biological material and its mineralisation in order to compare said data with the detected electrical response and to determine any required modification of at least one of the electrical signal and ultrasonic signal.
• the mineralising probe electrode advantageously transfers the mineralising agent to the biological material by iontophoresis. According to one embodiment, the mineralising probe electrode advantageously transfers the mineralising agent to the biological material by electrosonophoresis.
• ultrasound is generally used in the range of between about 20Hz to 200 MHz; typically from about 5 MHz to about 200MHz; suitably from about 10 MHz to about 150 MHz; more suitably from about 100 MHz to about 150 MHz.
• the detector is advantageously operable to determine, from the electrical response, the presence of at least one of exogenous proteins and lipids on or in the biological material.
• the apparatus may further comprise means for applying a conditioning agent.
• the conditioning agent may comprise at least one of an oxidising agent, de-proteinising agent and a de-lipidising agent.
• the conditioning agent comprises more than one of an oxidising agent, de-proteinising agent and a de-lipidising agent, typically the conditioning agent comprises at least a de-proteinising agent and a de-lipidising agent.
• the apparatus is advantageously operable to apply the ultrasonic signal and transfer the mineralising agent separately, sequentially or simultaneously.
• the apparatus is advantageously operable to apply the ultrasonic signal and the electrical signal separately, sequentially or simultaneously.
• the apparatus is advantageously operable to apply the modulated electrical signal and transfer the mineralising agent separately, sequentially or simultaneously.
• the apparatus is operable to apply the ultrasonic signal and an iontophoresis signal separately, simultaneously or sequentially and/or in combination. Generally the ultrasonic signal and the iontophoresis signal are applied simultaneously.
• the apparatus is advantageously adapted for use with hard tissue biological materials such as tooth and/or bone.
• the operation of the apparatus of the present invention can be interrupted in order to re-apply the conditioning agent thereby removing exogenous proteins and/or lipids.
• a mineralising agent for use with apparatus, as described above, for mineralising biological material.
• the mineralising agent may comprise at least one of a source of calcium ions and a source of phosphate ions and source of hydroxyl ions (such as water), optionally in the presence of a source of fluoride ions.
• the mineralising agent comprises a source of calcium ions and a source of phosphate ions and a source of hydroxyl ions (such as water).
• the mineralising agent comprises a source of calcium ions, a source of phosphate ions, water, and a source of fluoride ions.
• the mineralising agent may be in a form soluble in water or insoluble in water (in an aqueous dispersion) under the conditions generally used to operate the apparatus/conduct the method of the present invention.
• the mineralising agent may comprise casein phosphopeptide - amorphous calcium phosphate (CPP-ACP)
• the mineralising agent may comprise calcium, phosphate, hydroxy l/water and fluoride.
• the mineralising agent may comprise casein phosphopeptide - amorphous calcium fluoride phosphate (CPP-ACFP).
• the mineralising agent suitably comprises one or more mineralisation enhancers. More suitably, the mineralising agent comprises two mineralisation enhancers, wherein one of the enhancers is a source of calcium ions and the other is a source of phosphate ions.
• the mineralising agent preferably comprises a calcium:phosphate ratio of between 1 :1 and 22:10. More preferably, the mineralising agent comprise a calcium:phosphate ratio of between 3:2 and 22:10. More preferably, the mineralisation agent comprises a
• At least one of the mineralisation enhancers may comprise strontium.
• the mineralisation agent advantageously comprises nano-particles, having an average particle diameter of less than 500nm, generally less than 100nm, typically less than 50nm, suitably less than 10nm, more suitably from 1 to 10nm.
• the mineralisation agent consists of nano-particles.
• the average particle diameter of the mineralisation agent is 1 to 50nm.
• a mineralisation agent comprising or consisting of nano-particles is believed to allow a greater proportion of the mineralisation agent to be forced into the biological tissue, promoting a more efficient mineralising method, and/or greater retention of the mineralisation agent in the biological tissue.
• the nano-particles typically comprise at least one of a source of calcium ions, a source of phosphate ions, a source of hydroxyl ions and a source of fluoride ions.
• the nano- particles comprise calcium hydroxyapatite.
• kits comprising apparatus for mineralising a biological material, as described above, and a mineralisation agent as described above.
• the kit may further comprise a conditioning agent.
• a method of mineralising a biological material comprising the steps of: providing an ultrasound source, providing a mineralising agent, generating an ultrasonic signal from the ultrasound source, applying the ultrasonic signal and the mineralising agent to the biological material separately, sequentially or simultaneously.
• the method of the present invention generally involves the use of the apparatus as described herein.
• the method may be involve electrosonophoresis.
• electrosonophoresis the combination of ultrasound and iontophoresis
• a method of mineralising biological material allows a greater proportion of the mineralising agent to be forced into the biological material, rather than remaining on the surface of the biological material. This allows a more effective method of mineralisation. More mineralising agent is forced into the biological material in a shorter time period than equivalent methods using only iontophoresis.
• electrosonophoresis is also believed to promote greater retention of the mineralising agent in the biological material, meaning that the mineralisation of the biological tissue lasts for longer than methods using only iontophoresis,
• the method may further comprise the step of conditioning the biological material prior to applying at least one of the ultrasonic signal and mineralising agent thereto.
• the step of conditioning comprises at least substantially removing at least one of protein and lipids from the biological material (generally substantially removing both of proteins and lipids from the biological material).
• the step of conditioning preferably comprises the application of at least one of a deproteinisation agent and a delipidisation agent.
• the method advantageously further comprises the steps of: providing a first electrode and a second electrode, an electrical signal generator and a controller; generating an electrical signal between the first and second electrodes; detecting the electrical response of the electrical signal, between the first and second electrodes; and controlling the ultrasonic signal relative to the detected electrical response.
• the method advantageously further comprises the steps of providing a mineralising probe; providing a modulator; modulating the electrical signal between the mineralising probe and the second electrode and thereby cause the transfer of mineralising agent to the biological material using the electrical signal.
• the mineralising probe may be provided by the first electrode.
• the method advantageously further comprises the step of controlling the modulation of the electrical signal relative to the detected electrical response.
• the method advantageously further comprises the step of providing a reference electrode and controlling at least one of the modulation of the electrical signal and the ultrasonic from information derivable therefrom.
• the steps of controlling at least one of the ultrasonic signal and the electrical signal relative to the detected electrical response may comprise the steps of: comparing a dataset of characteristic electrical responses derived from a set of samples of biological material at various stages of mineralisation with the detected electrical response; and determining any required modification to at least one of the ultrasonic signal or electrical signal.
• the step of comparing the data set may comprise applying a function which defines the relationship between the mineralisation and the electrical response in order to compare said data with the detected electrical response.
• the step of comparing the data set may comprise applying a look-up table containing information relating to the electrical response of the biological material and its mineralisation; and comparing the said data with the detected electrical response.
• the method may further comprise the step of detecting the presence of at least one of proteins (such as exongenous proteins) and lipids on or in the biological material from the detected electrical response; typically detecting the presence of proteins and lipids.
• proteins such as exongenous proteins
• lipids on or in the biological material from the detected electrical response; typically detecting the presence of proteins and lipids.
• the mineralising agent is generally as described above.
• the mineralising agent may comprise casein phosphopeptide - amorphous calcium phosphate (CPP-ACP)
• the mineralising agent may comprise calcium, phosphate, hydroxyl/water and fluoride.
• the mineralising agent may comprise casein phosphopeptide - amorphous calcium fluoride phosphate (CPP-ACFP).
• the mineralising agent may be substantially insoluble in water under the conditions used in the method of the present invention. According to one embodiment of the present invention, the mineralising agent remains in or on the bone/dental tissue to which is it applied for at least 3 months, generally at least six months, typically at least one year from application thereto.
• the mineralising agent advantageously comprises one or more mineralisation enhancers. More advantageously, the mineralising agent comprises two mineralisation enhancers, wherein one of the enhancers is a source of calcium ions and the other is a source of phosphate ions.
• the mineralising agent may comprise a calcium:phosphate ratio of between 1 :1 and 22:10.
• the mineralising agent comprises a calcium:phosphate ratio of between 3:2 and 22:10. More preferably, the mineralisation agent comprises a calcium: phosphate ratio of approximately 10:6.
• At least one of the enhancers may comprise strontium.
• the mineralisation agent advantageously comprises nano-particles.
• the nano-particles preferably comprise at least one of calcium, phosphate, hydroxyl and fluoride.
• the nano-particles may comprise calcium hydroxyapatite.
• the method is advantageously adapted for use in mineralising hard tissue such as tooth and/or bone.
• Figures la and lb are graphs which show the applied voltage and the current decay rate for a healthy and a demineralised tooth
• Figure 2a is a flow diagram which shows an embodiment of the method of the present invention and figure 2b is a block diagram of an apparatus for implementing the method of figure 2a;
• Figures 3a and 3b are schematic representations of embodiments of the present invention utilising ultrasound only ( Figure 3a) and combined ultrasound and iontophoresis ( Figure 3b);
• Figure 4 is a more detailed schematic representation of the controller of the embodiment of Figure 1 ;
• Figures 5a and 5b are more detailed schematic representations of the ultrasonic probe and the iontophoresis probe, resepectively, of the embodiments of figures 3a and 3b;
• Figure 6 is a flow diagram showing a first embodiment of the method of the present invention.
• FIG. 7 is a flow diagram showing another embodiment of the method of the invention.
• the present invention provides an apparatus and method for mineralising a biological material.
• the invention is particularly suitable for remineralisation of teeth where decay by demineralisation has occurred or for occluding dental tubules to treat dentine
• the apparatus and method described herein is not restricted to the remineralisation of teeth but can be used to mineralise other biological material but is particularly applicable to the mineralisation of hard tissue such as, for example, it may be used in the remineralisation of bones for the treatment of osteoporosis, osteopenia or periodontal disease.
• the apparatus and method of the present invention involve electrosonophoresis.
• spatial imaging data or 3D structural information can be used to generate different characterising parameters, including, tracking changes (and/or relative changes) in grey- scale values (in micro-CT images) in a variety of different parallel vectors in any one of many different planes, to generate an average representation of the mineral density changes in the direction of those vectors.
• the averaging process is performed preferably over the whole volume of the lesion; and the resulting information therefrom is processed to calculate, amongst other parameters, the depth of the carious lesion in the direction of the pulp.
• the image analysis technique provides substantially more information than that normally available to a dentist. Thus, it may be possible to determine other lesion parameters which may be more useful in characterising the loss of mineral density than the traditionally-used lesion depth parameter.
• changes in the impedance and/or resistance of a tooth can be detected on the application of an AC signal or a DC constant current or constant potential difference.
• the application of a pulse or square- wave current or potential difference to a healthy or demineralised tooth also yields dynamic information from the plot of current (or potential) vs time.
• Figure la is a graph 1 of voltage against time which shows a pulsed voltage 3 of substantially constant magnitude.
• Figure lb is a graph of current against time which shows the current decay rate in response to the applied potential difference (voltage) pulse for a healthy tooth and one which has been demineralised.
• the curve 7 shows the current response for the healthy tooth and the curve 9 shows the response for the demineralised tooth.
• a relation may be formed between the mineral density profiles determined from the above-mentioned image processing technique and a measured temporal electrical response profile.
• the present invention forms the relation through image-analysis and electrical properties analysis of a large number of healthy teeth and teeth with carious lesions by establishing an analytical model which creates a mathematical function to describe this relationship.
• the present invention may employ a look-up table between the measured electrical response data and average mineral density values (determined from the above image analysis techniques) obtained from the studies of the healthy and diseased teeth
• a look-up table between the measured electrical response data and average mineral density values (determined from the above image analysis techniques) obtained from the studies of the healthy and diseased teeth
• micro-CT techniques can be used in which data is calibrated against a plurality of phantoms, so as to ensure that the measured variation in grey scale values is actually representative of a change in mineral density though a tooth, as opposed to an aberrant effect (or imaging artefacts). The above process will be described in more detail below.
• the apparatus of the present invention employs a feedback mechanism, wherein an electrical measurement (which may be AC or DC related) is made whilst a tooth is being remineralised by iontophoresis.
• the electrical measurement is related to the mineral density of a carious lesion in the tooth (through the above-mentioned relation and/or look-up table formed during an offline process) to calculate an appropriate control signal for the apparatus to optimally tune the iontophoretic process.
• FIG. 2a shows an embodiment of the method of the present invention which comprises the following steps.
• a pre-step which involves calibrating the grey-scale values obtained from a micro-CT analysis (used in forming the mineral density values employed in the above- mentioned relation and/or look-up table) a plurality of phantoms (comprising a homogeneous isotropic material which substantially matches dental material) are scanned using a micro-CT device.
• the phantoms comprise hydroxyapatite disks representing a particular material density.
• a plurality of healthy teeth and teeth with carious lesions are each subjected to a similar scanning process, together with the phantoms.
• the calculated mineral densities of the scanned teeth are processed using a known segmentation technique to identify the boundaries of any lesions therein.
• a profile of the mineral density is established within the boundaries determined by the segmentation process; and the mineral density profiles are related to a steady-state or temporal electrical measurement obtained from the same teeth.
• Step 1 During the application of an ultrasonic signal and generally, iontophoresis, a constant potential difference or current is applied to a tooth with a carious lesion 13. An electrical response function is measured 15 from the tooth under treatment; and the relation (and/or look-up table) established in Step 1 is used to determine 17 the mineral density of the carious lesion.
• the mineral density range of the healthy tooth material proximal to the boundaries established during step 1 is determined 19. This is used to establish the desired degree of remineralisation required of the ultrasonic signal (and generally iontophoretic) treatment.
• a change in the magnitude of the ultrasonic (and generally iontophoretic) signal is calculated 21 , the calculated change being sufficient to drive mineral into the lesion so that the mineral density of the lesion more closely matches that of the healthy dental material.
• the apparatus of Figure 2b comprises a logic block 23, which in addition to receiving an indication of the desired change in the magnitude of the ultrasonic (and generally iontophoretic) signal (from Step 4), receives information regarding the time 25 over which the iontophoresis treatment has been operating.
• the logic block 23 also receives additional protocol information 27 regarding times for example at which the ultrasonic (and generally iontophoresis) should be started or stopped (e.g. to allow the electrical probe to be cleaned and further conditioning agent 29 to be applied thereto).
• the apparatus according to the present invention may function to mineralise biological material either using ultrasound alone to propel mineralising agent into the biological material or a combination of ultrasound and iontophoresis.
• FIG 3a shows a first embodiment of an apparatus 31 for mineralising a biological material, in accordance with the present invention, comprising an ultrasonic probe 33 having a handle 35, a neck 37 and head 39.
• the ultrasonic probe 33 is connected to an ultrasound source 40 and a controller 41 , by cable 45, which in turn is connected to a second counter electrode 43 by cable 47.
• Electrode 43 may be a hand-held or mouth or lip "loop" electrode.
• FIG. 3b shows a second embodiment of an apparatus 131 for mineralising a biological material, in accordance with the present invention, comprising an ultrasonic probe 133a having a handle 135a, a neck 137a and head 139a.
• the apparatus further comprises an iontophoresis probe 133b, operable as a fist electrode, having a handle 135b, a neck 137b and a head 139b.
• the ultrasonic probe 133a is connected to an ultrasound source 140 and a controller 141 , by cable 145, which in turn is connected to a second counter electrode 143 by cable 147.
• Electrode 143 may be a hand-held or mouth or ⁇ ' ⁇ " electrode.
• the iontophoresis probe 133b is also electrically connected to the controller 141.
• FIG. 4 shows, in more detail, the controller 41 which comprises a modulator 49 which adjusts the ultrasonic signal to the ultrasonic probe 33a (133a) and, if the iontophoresis probe 133b in accordance with the second embodiment is utilised, modulates the shape and/or frequency and/or amplitude of the waveform sent to the probe 133b.
• a modulator 49 which adjusts the ultrasonic signal to the ultrasonic probe 33a (133a) and, if the iontophoresis probe 133b in accordance with the second embodiment is utilised, modulates the shape and/or frequency and/or amplitude of the waveform sent to the probe 133b.
• Figure 5a shows the ultrasonic probe 33 (133a), in more detail, wherein it has an ultrasonic waveguide 34 which extends through the handle 34 of the probe to the ultrasound source 40.
• a reservoir 55 (155a) for storing mineralising agent 57 (157a).
• the mineralisation agent is propelled out from the reservoir 55 (155a) through the head 39 (139a) of the probe 33 (133a) by the ultrasonic signal and into contact with the biological material such as, for example, a tooth or bone.
• Figure 5b shows the iontophoresis probe 133b, in more detail, wherein the cable 45 extends through the handle 135b of the probe 133b to a reservoir 155b containing a mineralising agent 157b.
• the mineralisation agent is propelled out from the reservoir 155b, by the electrical signal (iontophoresis) through the head 139b of the probe 133b and in to contact with the biological material such as, for example, a tooth or bone.
• the mineralising agent may be stored in other ways such as in a porous structure or a gel which may be applied directly to a tooth.
• the mineralising agent is stored in a chamber in the probe it can be introduced onto the probe surface by making the chamber of flexible material to allow the mineralising agent to be squeezed out.
• the chamber may have a plunger or similar component which pushes the mineralising agent out of the chamber.
• the mineralising agent is typically held separately from the device or embodied as a detachable 'probe tip' which detachably attachable to the end of the probe.
• FIG. 6 is a flow chart 61 which shows a method of the present invention in which the ultrasonic signal and (if iontophoresis is used) the waveform of the electrical signal in the circuit formed from the first (probe) electrode 33(133a and/or 133b) and the second counter electrode 43 (143) is controlled so as to transfer a mineralising agent to the biological material 63.
• the electrical response of the circuit is then detected 65 and the detected signal is analysed so as to determine whether or not the signal needs to be modified and, if so to what extent, in response to the detected electrical response of the circuit 67.
• the dentist identifies, within a patient, a specific tooth site which is to be remineralised. Thereafter a conditioning agent is applied and the site is cleansed to remove exogenous proteins and/or lipids from the site.
• the conditioning agent may be propelled into a hypo-mineralised or demineralised caries lesion, by iontophoresis, utilising the probe and counter electrodes, to optimise the disruption and removal of the exogenous protein and/or lipid content.
• the probe 33 (133a/133b) is inserted into the mouth of the patient and on to the tooth site.
• the counter electrode 43 (143) is connected to the patient.
• the probe(s) which in this example comprises an ultrasonic (and optionally an iontophoretic) device, propels the mineralising agent 57 (157) through the external surface of the tooth in order to remineralise the caries lesion at that tooth site.
• the electrical circuit formed by the probe(s) 33 (133a/133b), patient and counter electrode 43 (143) provides an output signal which identifies changes in the electrical response of the circuit which have been caused by the ongoing remineralisation process.
• the electrical response is detected by detector 53, the signal is passed to the controller 51 which processes and compares the electrical response to a dataset of known, experimentally obtained electrical responses to remineralisation. These responses provide 3D structural information on the amount and location of remineralisation of the tooth.
• the controller is therefore able to send program instructions to the modulator to alter the ultrasonic signal and waveform of the electrical signal input to the probe(s) 33 (133a/133b) by changing its frequency and/or amplitude and/or shape.
• the modulator 49 provides an output to the probe(s) 33 (133a/133b) which in turn determines the manner in which the mineralising agent is propelled through the external surface of the tooth.
• a response to changes in the remineralisation pattern of the tooth can be made in real time or otherwise.
• a sample having dental caries, or other general defects is scanned using a 3D tomography system (e.g. x-ray, MRI, neutron (ultrasound).
• a calibration phantom is used to determine the relationship between attenuation coefficient and electron density; hardware and software solutions are used to minimise intrinsic image artefacts (e.g. beam hardening, ring artefacts, scattering).
• Reconstruction of the sample is achieved using acquired 2D angular projection images, and is accomplished for different voxel (i.e. 3D pixels) or spatial resolutions.
• 3D image processing algorithms are employed to calculate spatial distributions of electron density, as represented by attenuation data linked to the phantom. These distributions provide information on the degree of mineralization of relevant volumes of interest.
• the sample is rescanned and subjected to the above mentioned methodologies.
• the subsequent distributions (before and after treatments) of mineral density of relevant volumes of interest are compared to inform of induced changes in mineralization patterns.
• This process is repeated for samples with varying degrees of remineralisation to provide information on changes in internal sample structure, which can be related to changes in electrical responses of the sample which occurred during the treatment of the sample.
• the described technique would inform any spatial heterogeneity of remineralisation, providing feedback from the electrical responses of the sample to the spatial location of remineralisation.
• Representative experimentally acquired datasets are encoded into the device library to provide characteristic signatures of the spatial location and distribution of mineral densities which enable the clinician to decide on real-time responses to
• the initial settings may involve the use of controlled potential coulometry where longer pulses are applied or chrono-amperometry where shorter pulses are applied.
• Feedback on the nature and extent of the remineralisation process provided by the present invention includes information about if and when to switch the settings to controlled current coulometry to optimise the remineralisation throughout the lesion.
• the current is at a constant level which means that the flow of the remineralising agent would be constant also. This would be desirable in promoting a constant rate of remineralisation, since the rate of remineralisation is expected to be directly proportional to the amount of current flowing. Alternatively, the current may be allowed to fall as a function of time and so the rate of remineralisation is not constant with time.
• the electrical response of the circuit gives information indicative of the build-up of exogenous proteins and/or lipids in the area of interest.
• the flow diagram 71 illustrates the transfer of a mineralising agent to the biological material 73.
• the electrical response of the circuit is then detected 75 and the detected signal is analysed so as to determine whether, and the extent to which, the ultrasonic signal and electrical signal needs to be modified in response to the detected electrical response of the circuit 77.
• the detector of the present invention is adapted to detect 81 changes in the electrical response that are as a result of a build up of exogenous proteins, lipids and other materials. Once detected the remineralisation process is interrupted 83 and a conditioning agent is re-applied 85 for a specific period. Thereafter, the process of remineralisation may resume.
• the presence of the exogenous proteins and/or lipids may be indicated by the apparatus of the present invention by analysis of the electrical response. In these circumstances, the user will be advised that a re-conditioning step is required and will take the appropriate action to re-apply a conditioning agent.
• the apparatus is provided with a reference electrode which in this example comprises a small Ag/ AgCI wire placed close to the probe electrode.
• the reference electrode allows more precise control of electrical potential and is of particular use when large currents are required to treat large lesions.
• the impedance of the tooth can be measured by the application of an AC signal as described above.
• a current interruption technique can be used whereby a current is applied for a certain amount of time and then the circuit is broken rapidly using a relay. The decay of the potential with time can give information on the resistance of the tooth.
• the invention can be used in the preconditioning of, for example, a tooth where ultrasonic signals (and generally iontophoresis) are used in preconditioning.
• a conditioning agent may be propelled into a hypo-mineralised or demineralised caries lesion, by ultrasonic signals (and generally iontophoresis) to optimise the disruption of the exogenous protein and lipid content and then the polarity of the iontophoresis reversed, if required, in order to aid the removal of the proteinacious and other organic material from the hypo-mineralised or demineralised tissue.
• suitable agents include bleach, detergent, chaotropic agents such as urea, high phosphate concentrations, cocktails of proteases (e.g.
• a kit comprises apparatus as described above and a mineralising agent.
• the kit may further comprise a conditioning agent.
• the conditioning agent is an oxidising agent, de-proteinising agent or a de-lipidising agent.
• a mineralising agent comprises a source of phosphate, calcium and hydroxy l/water.
• the remineralising agent may comprise casein phosphopeptide-amorphous calcium phosphate (CPP-ACP).
• the remineralising agent may comprise nano-particles of (calcium) hydroxyapatite.
• the remineralising agent contains fluoride.
• An example of such a remineralising agent is casein phosphopeptide-amorphous calcium fluoride phosphate (CPP-ACFP).
• the remineralising agent also advantageously includes one or more remineralisation enhancers.
• the remineralising enhancers are sources of calcium and phosphate ions.
• remineralisation enhancers may include, but are not limited to, Dicalcium phosphate dehydrate (DCPD), mineral brushite; Dicalcium phosphate anhydrous (DCPA), mineral monetite; Octacalcium phosphate (OCP); alpha-tricalcium phosphate (alpha-TCP); beta-tricalcium phosphate (beta-TCP); Amorphous calcium phosphate (ACP); Calcium- deficient hydroxyapatite (CDHA); Hydroxyapatite (HA or OHAp); Fluorapatite (FA or FAp); Tetracalcium phosphate (TTCP or TetCP), mineral hilgenstockite); nano-particles of hydroxyapatite or fluorhydroxyapatite.
• DCPD Dicalcium phosphate dehydrate
• the remineralisation enhancer is strontium.
• the remineralising agent may include at least two remineralisation enhancers wherein one of the enhancers is a source of calcium ions and the other is a source of phosphate ions.
• the remineralising agent may include a source of calcium e.g. calcium hydroxide and a source of phosphate e.g. orthophosphoric acid.
• the ratio of calcium:phosphate in the remineralising agent may be between 1 :1 and 22:10.
• calcium:phosphate is about 10:6 (i.e. 1.67), which represents the ratio of calcium to phosphate ions in calcium hydroxyapatite.
• the ratio of calcium:phosphate in the remineralising agent may be between 9:6 and 22:10.
• the ration of calcium:phosphate in the remineralising agent may greater than 1 :1 but less than 3:2 (i.e. 1.0 up to 1.49).
• the remineralising agents may thus be selected from the following:
• Ca:P ratio 1.67: e.g. Hydroxyapatite (including nano-particles): Fluorapatite.
• the remineralising agent may be prepared from its component parts by driving in calcium ions sonophoretically (in aqueous solution) and subsequently driving in phosphate ions (in aqueous solution) with a second sequence of sonophoresis - the calcium and phosphate ions would thus meet within the lesion during the second sequence of sonophoresis and precipitate out as a calcium phosphate mineral (or minerals).
• the hydroxyl ion of the generated apatite would come from the aqueous solution.
• the water-soluble calcium- containing agent may be, for example, calcium hydroxide, calcium chloride, or calcium nitrate; the water-soluble phosphate-containing agent may be, for example, orthophosphoric acid (H 3 PO 4 ), sodium (or potassium) hydrogen phosphate, sodium (or potassium) dihydrogen phosphate or magnesium phosphate.
• the calcium agent containing solution may be separate from the phosphate agent containing solution, or combined into one solution.
• a preferred method of the invention may comprise the steps of: i) pre-conditioning the biological material (hard tissue) to remove protein and/lipids, and ii) applying to the hard tissue a calcium phosphate-containing aqueous solution whilst separately, sequentially or simultaneously applying ultrasound.
• the pre-conditioning step can be effected with or without the use of ultrasound to drive in the de-proteinisation agent, e.g. sodium
• hypochlorite The frequency of this ultrasound can be in the range which will generate cavitation or Ultrasonic streaming.
• a further preferred method of the invention comprises the steps of i) pre-conditioning the biological material (hard tissue) to remove protein and/lipids ii) applying to the tissue a calcium-containing aqueous solution or phosphate-containing aqueous solution whilst separately, sequentially or simultaneously applying sonophoresis, and iii) either (a) applying a phosphate-containing aqueous solution where in (ii) a calcium-containing aqueous solution was applied or (b) applying a calcium-containing aqueous solution where in (ii) a phosphate- containing aqueous solution was applied whilst separately, sequentially or simultaneously applying sonophoresis.
• the pre-conditioning step is performed, with or without the application of ultrasound, prior to application of the remineralising agent/ultrasound.
• the pre-conditioning step may further comprise treatment with a hypochlorite and preferably treatment with an acid, more preferably, phosphoric acid.
• the method, according to the present invention may be used for the treatment or alleviation of dental caries and/or dental fluorosis in a mammal. It may also be used for remineralising of hypo-mineralised or de-mineralised (carious) dentine.
• the present invention also provides a remineralising agent for use in ultrasonic remineralising treatment of hard tissue which has been subject to pre-conditioning to remove protein and/or lipids, the remineralising agent being a source of both phosphate and calcium.
• a variety of mineralising agents may be used, including a mixture of mineralising agents.
• the mineralising agent may depend upon the tissue to be treated. However, preferably, the mineralising agent is a phosphate or calcium source, preferably a source of phosphate and calcium.
• An especially preferred mineralising agent is casein phosphopeptide-amorphous calcium phosphate (CPP-ACP).
• the mineralising agent may be a fluoride containing agent as hereinbefore described, such as casein phosphopeptide-amorphous calcium fluoride phosphate (CPP-ACFP).
• Other mineralising agents may comprise calcium phosphate compounds, such as fluoroapatite, monetite, brushite, amorphous calcium phosphate, hydroxyapatite, etc.
• additional elements such as strontium.
• hypo-mineralised tissue and demineralised tissue are intended to include any tissue that is deficient in its level of mineralization and includes tissue, such as tooth, that is substantially or completely demineralised, e.g. as a result of the dental caries process, thus including dental caries lesions, or a result of acid erosion, thus including 'surface-softened' enamel or dentine.
• the ultrasound may comprise the application of a single frequency or a range of frequencies.
• the ultrasound may comprise the application of a mixture of frequencies, for example, the combination of frequencies may be applied in specific sequences so as to optimise remineralisation.
• a preconditioning step is also included prior to application of the mineralising agent/ultrasound.
• the pre-conditioning step may vary but may, for example, comprise the removal of proteins and/or lipids prior to application of the mineralising agent/ultrasound.
• the preconditioning step comprises a variety of processes or a mixture of processes.
• Any suitable protein removing agent can be used in the preconditioning step of the present invention.
• the agent is required to reduce the proteinaceous barrier formed over the surface to be treated, such as the pellicle over teeth or the exogenous protein within a caries lesion.
• the preconditioning step may optionally include the use of ultrasound and the various preconditioning agents, e.g. protein removing agents, may be used in a variety of combinations and/or sequences. Furthermore, any of the pre-conditioning agents may be propelled into a hypo-mineralised or demineralised region, e.g. caries lesion, by ultrasound to optimise the disruption of the protein layer and removal the proteinacious material from the hypo-mineralised or demineralised tissue.
• suitable agents include bleach, detergent, chaotropic agents such as urea, high phosphate concentrations, cocktails of proteases (e.g. endopeptidases, proteinases and exopeptidases) and any other protein solubilising, disrupting or hydrolysing agent.
• Suitable bleaches include sodium hypochlorite and peroxide bleaches.
• the bleach is an alkaline bleach.
• the alkaline bleach is sodium hypochlorite.
• the protein disrupting agent acts to solubilise and partially or wholly remove proteins from the surface of the tooth mineral, e.g. proteins of the pellicle on the tooth surface.
• the preconditioning step comprises treatment with an acid, such as an organic acid, e.g. acetic acid, an inorganic acid, e.g. phosphoric acid, or a bleaching agent, e.g. hypochlorite, for example, sodium hypochlorite.
• the application of the ultrasound in the lower frequency range acts to generate cavitation during the pre-conditioning step which promotes removal of the exogenous organic material from the surface of and within the lesion.
• the mineralising agent may be applied in a variety of forms, for example, in the form of a gel or mousse.
• a gel or mousse for use in the treatment of tooth other oral applications known per se may be used.
• Pre-conditioning is preferably carried out not more than one minute before the application of the mineralising agent. More preferably, the mineralising agent is applied almost contemporaneously, i.e. within seconds, of the preconditioning.
• a preferred treatment sequence involves repeated conditioning followed by mineralising, particularly in a case where the mineralising agent includes material, such as protein, which is removed in a subsequent conditioning step.
• the present invention further provides a method of cosmetic treatment of tissue by application to the tissue of a mineralising agent whilst separately, sequentially or simultaneously applying ultrasound. It will be further understood by the person skilled in the art that the method of the invention may also be advantageous in the field of orthopaedics, for example, in the treatment of bone pathologies in mammals, i.e. human or animals, such as fractures and/or during surgery.
• the present invention provides improved mineralisation of tissue.
• conventional methods of remineralisation of tooth generally comprise remineralisation of the surface tissue, i.e. remineralisation of enamel.
• Dentine is the term for a hard substance which is related to bone and forms the core of the tooth in mammals and man. Dentine consists to the extent of approximately 30% of a cell-free organic base substance, in particular glycoproteins in which collagen fibres are incorporated. The inorganic constituents are predominantly hydroxyapatite, fluoroapatite and small amounts of carbonates, magnesium and trace elements.
• the present invention further provides a kit for use in ultrasonic remineralising treatment of tissue comprising a pre-conditioning agent and a mineralising agent.
• the remineralising agent may comprise a source of calcium and phosphate ions such as defined herein.
• the pre-conditioning agent and the remineralising agent are present in the kit in a suitable form for application, for instance, a liquid or a gel form.
• the kit may also provide an applicator for applying the, or each, agent to the site of treatment.
• an applicator for applying the, or each, agent to the site of treatment.

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