Modus Laboratories is a contract research company for the oral healthcare industry. We combine scientific discovery with customer focused research and development. Our expertise is to test experimental and commercial materials, formulations and treatments and evaluate the performance to understand the biological significance. Our companies ethos is for high quality results and products, a rapid response and a scientific focus to the modern day customers’ expectations.
Company History
Modus Laboratories was founded in 2009 by Dr. Richard Willson. After spending fifteen years working at GlaxoSmithKline, eight years at the pharmaceutical division as a Scientific Investigator, based at Upper Providence, Philadelphia and Harlow, Essex and seven years at the oral healthcare division at Weybridge, Richard went on to set up Modus Laboratories. Initially occupying laboratories at the Science and Technology Centre at Reading University we relocated to the Thames Valley Science Park in 2018, opened by Sir David Bell, vice-chancellor of Reading University.
Modus Laboratories customer values.
Modus Laboratories has worked with many companies and institutions around the world from Australia to America. Over time, customer values have cemented into the companies DNA and we strive to uphold these values. Communication of project timings, status, results and added value of interpretation through many years of expertise working in the industry and access to extensive resources. We have a pedigree of producing high quality results within demanding deadlines.
Please note that this website is incomplete in placesbut we will strive to complete as soon as possible.
Contract Research for the Oral Healthcare Industry.
Industry solution.
Modus Laboratories is a contract research company for the oral healthcare industry. We combine scientific discovery with customer focused research and development. Our expertise is to test experimental and commercial materials, formulations and treatments and evaluate the performance to understand the biological significance. Our companies ethos is for high quality results and products, a rapid response and a scientific focus to the modern day customers’ expectations.
Company History
Modus Laboratories was founded in 2009 by Dr. Richard Willson. After spending fifteen years working at GlaxoSmithKline, eight years at the pharmaceutical division as a Scientific Investigator, based at Upper Providence, Philadelphia and Harlow, Essex and seven years at the oral healthcare division at Weybridge, Richard went on to set up Modus Laboratories. Initially occupying laboratories at the Science and Technology Centre at Reading University we relocated to the Thames Valley Science Park in 2018, opened by Sir David Bell,vice-chancellor of Reading University.
Modus Laboratories customer values.
Modus Laboratories has worked with many companies and institutions around the world from Australia to America. Over time, customer values have cemented into the companies DNA and we strive to uphold these values. Communication of project timings, status, results and added value of interpretation through many years of expertise working in the industry and access to extensive resources. We have a pedigree of producing high quality results within demanding deadlines.
The following lists some of the services and analytical testing that we provide at Modus Laboratories. The core testing follows procedures that have been subjected to peer reviewed publications and the scrutiny of industry standards. Project that fall outside the conventional procedures, we will be please to develop suitable test methods and procedures to keep pace with rapidly changing technologies.
Contract Research for the Oral Healthcare Industry.
The following lists some of the services and analytical testing that we provide at Modus Laboratories. The core testing follows procedures that have been subjected to peer reviewed publications and the scrutiny of industry standards. Project that fall outside the conventional procedures, we will be please to develop suitable test methods and procedures to keep pace with rapidly changing technologies.
Micro indentation measures the hardness of materials. There is a correlation between the hardness of tooth enamel and dentine and its mineral content. The environment of the mouth can become acidic, often caused by diseases such as poor saliva flow or microbial activity as a consequence of sugary foods and drinks. Tooth enamel and dentine can soften due to demineralisation and micro indentation is used to measure the extent of demineralisation, the effects of treatments designed to reminerailise the damaged enamel and measure the effects of treatments designed to protect from acid erosion.Sample preparation for transverse micro-radiography. Some say the gold standard for measuring the remineralisation of caries lesions.Blue light shone on healthy enamel causes the enamel to fluoresce in the green spectrum The intensity of the fluorescence is directly proportional to the calcium mineral content of the enamel. Enamel that has been demineralised by, for example, by acidic drinks such as orange juice or cola, will cause the enamel to fluoresce less. QLF can then be used as a diagnostic tool for measuring enamel demineralision and to measure the effectiveness of treatments for remineralising damaged enamel.Tooth sensitivity is often caused by the movement of fluids through dentine tubules stimulating pain and is known as the hydrodynamic theory. Hydraulic conductance is a measurement of the rate and volume of fluid passing through the dentine and is a valuable tool for measuring the effects of dentine treatments designed to reduce the fluid flow through the dentine tubules. A different approach in treating tooth sensitivity is to reduce the pain associated with sensitivity Potassium nitrate is reportedly an effective treatment for dentine hypersensitivity, alleviating pain by neutralising exposed nerves. Potassium flux measurements can determine the effectiveness of potassium containing formulations to release free potassium ions and to measure the rate and quantity that can pass through dentine to the nerve endings.Physicists Taylor and Aris discovered a micro-capillary flow-based technique where a solute pulse injected into a laminar flow of solvent spreads out due to the actions of convection and radial diffusion. Recording of the equilibrium concentration profile of the dispersed solute allows the molecular diffusion coefficient to be calculated and so the hydrodynamic radius of solute.Another way to measure the occluding properties of a treatment is to image the tubules using a scanning electron microscope and to calculate the proportion of the tubules that are occluded using a categorical grading scale. Imaging a cross section thorough the tubule tracts gives information on how far the formulation has penetrated the tubule.To understand tooth whitening we should explore what is meant by tooth staining. Tooth staining comes under two broad categories: Intrinsic staining where the tooth is stained from the inside out. There are a number of causes including medicines such as erythromycin or diseases of the dentine. It can also be caused by caries lesions. The second is extrinsic staining caused by drinking red wine , tea, chlorhexidine (in some mouthwashes), iron, copper, silver solutions (an old treatment for halitosis), tin compounds (e.g. tin fluoride also found in some toothpastes). Surface enamel gloss incorporating ASTM D523 Standard test method for measuring gloss at a specula angle of 60°. Glossometry is often used in combination with our automated brushing machine to measure glossiness of enamel after brushing with formulations designed to enhance glossiness.Calculus is a hard mineral deposit that can form on teeth, prostheses, braces even oral jewellery. It varies in colour from yellow to black and is formed from bio-film accumulating on stagnant regions of hard oral material. Absorbing organic particles from food and minerals mainly from saliva the bio-film undergoes mineralisation and calcification to form plaque. Accumulation of bacteria can lead to gum infection, dental caries, loosening of the teeth, and other disorders.Based on the US FDA monograph #40 using a methyl cellulose lactic acid gel system to form lesions. This method quantifies fluoride activity from a formulation.The “Pig Tongue” model measures the retention of actives in a simulated oral cavity after treatment with a test formulation. Pig tongue is a recognised model for human oral soft tissue and is routinely used as a substitute. The human mouth has many surfaces other than teeth (hard tissue) in which actives such as fluoride can accumulate. In the pig tongue model it is used to measure the rate at which fluoride or other actives are released and so build a profile of how the test formulation might enhance the release profile of the actives.Scantron non contact 3D profilometer uses chromatic confocal sensors to map a surface of a material with high degree of three dimensional resolution. Profilometry is our standard method to measure volume changes in bulk tissue loss and to examine surface profiles after mechanical abrasion or chemical erosion. Enamel and dentine solubility models measures the dissolution and of apatite minerals using automated pH titration. The quantity of mineral loss can be measured before and after treatment with a test formulation to determine the effectiveness. Measurement of enamel or dentine solubility is an aid in product / active ingredient development. The pH stat titration will keep a solution at a constant pH whilst measuring the volume of either acid or base added. Hydroxyapatite added to an acid solution will start to dissolve but also neutralise the acidic solution. pH stat titration will compensate to maintain the pH with precisely added volumes of added acid or base. The amount of hydroxyapatite that has dissolved and the dissolution rate can be deduced.Gravimetric vapour sorption measures the mass change of a material as a function of vapour partial pressure. For any given partial pressure the material is perfused with the vapour until a state of equilibrium has been achieved. For example the quantification of carbonates in tooth enamel. Environmental carbonates have been shown to be substituted into tooth apatite crystals at phosphate or hydroxyl groups. A high carbonate to-phosphate ratio result in enamel that is particularly susceptible to acid attack (Sobel A.E. Dietary Phosphate and Caries Susceptibility, Dent Prog 2:48-52, 1962).
Micro indentation measures the hardness of materials. There is a correlation between the hardness of tooth enamel and dentine and its mineral content. The environment of the mouth can become acidic, often caused by diseases such as poor saliva flow or microbial activity as a consequence of sugary foods and drinks. Tooth enamel and dentine can soften due to demineralisation and it has been shown that micro indentation can measure the extent of demineralisation, the effects of treatments designed to remineralise the damaged enamel and measure the effects of treatments designed to protect from acid erosion.Sample preparation for transverse micro-radiography. Some say the gold standard for measuring the remineralisation of caries lesions.Blue light shone on healthy enamel causes the enamel to fluoresce in the green spectrum The intensity of the fluorescence is directly proportional to the calcium mineral content of the enamel. Enamel that has been demineralised by, for example, consuming a can of coke, will cause the enamel to fluoresce less. QLF can then be used as a diagnostic tool for measuring the effects of demineralising enamel and to measure the effectiveness of treatments for remineralising damaged enamel.Tooth sensitivity is often caused by the movement of fluids through dentine tubules stimulating pain and is known as the hydrodynamic theory. Hydraulic conductance is a measurement of the rate and volume of fluid passing through the dentine and is a valuable tool for measuring the effects of dentine treatments designed to reduce the fluid flow through the dentine tubules. A different approach in treating tooth sensitivity is to reduce the pain associated with sensitivity Potassium nitrate is reportedly an effective treatment for dentine hypersensitivity, alleviating pain by neutralising exposed nerves. Potassium flux measurements can determine the effectiveness of potassium containing formulations to release free potassium ions and to measure the rate and quantity that can pass through dentine to the nerve endings.Physicists Taylor and Aris discovered a micro-capillary flow-based technique where a solute pulse injected into a laminar flow of solvent spreads out due to the actions of convection and radial diffusion. Recording of the equilibrium concentration profile of the dispersed solute allows the molecular diffusion coefficient to be calculated and so the hydrodynamic radius of solute.Another way to measure the occluding properties of a treatment is to image the tubules using a scanning electron microscope and to calculate the proportion of the tubules that are occluded using a categorical grading scale. Imaging a cross section thorough the tubule tracts gives information on how far the formulation has penetrated the tubule.To understand tooth whitening we should explore what is meant by tooth staining. Tooth staining comes under two broad categories: Intrinsic staining where the tooth is stained from the inside out. There are a number of causes including medicines such as erythromycin or diseases of the dentine. It can also be caused by caries lesions. The second is extrinsic staining caused by drinking red wine , tea, chlorhexidine (in some mouthwashes), iron, copper, silver solutions (an old treatment for halitosis), tin compounds (e.g. tin fluoride also found in some toothpastes). Surface enamel gloss incorporating ASTM D523 Standard test method for measuring gloss at a specula angle of 60°. Glossometry is often used in combination with our automated brushing machine to measure glossiness of enamel after brushing with formulations designed to enhance glossiness.Calculus is a hard mineral deposit that can form on teeth, prostheses, braces even oral jewellery. It varies in colour from yellow to black and is formed from bio-film accumulating on stagnant regions of hard oral material. Absorbing organic particles from food and minerals mainly from saliva the bio-film undergoes mineralisation and calcification to form plaque. Accumulation of bacteria can lead to gum infection, dental caries, loosening of the teeth, and other disorders.Based on the US FDA monograph #40 using a methyl cellulose lactic acid gel system to form lesions. This method quantifies fluoride activity from a formulation.The “Pig Tongue” model measures the retention of actives in a simulated oral cavity after treatment with a test formulation. Pig tongue is a recognised model for human oral soft tissue and is routinely used as a substitute. The human mouth has many surfaces other than teeth (hard tissue) in which actives such as fluoride can accumulate. In the pig tongue model it is used to measure the rate at which fluoride or other actives are released and so build a profile of how the test formulation might enhance the release profile of the actives.Scantron non contact 3D profilometer uses chromatic confocal sensors to map a surface of a material with high degree of three dimensional resolution. Profilometry is our standard method to measure volume changes in bulk tissue loss and to examine surface profiles after mechanical abrasion or chemical erosion. Enamel and dentine solubility models measures the dissolution and of apatite minerals using automated pH titration. The quantity of mineral loss can be measured before and after treatment with a test formulation to determine the effectiveness. Measurement of enamel or dentine solubility is an aid in product / active ingredient development. The pH stat titration will keep a solution at a constant pH whilst measuring the volume of either acid or base added. Hydroxyapatite added to an acid solution will start to dissolve but also neutralise the acidic solution. pH stat titration will compensate to maintain the pH with precisely added volumes of added acid or base. The amount of hydroxyapatite that has dissolved and the dissolution rate can be deduced.Gravimetric vapour sorption measures the mass change of a material as a function of vapour partial pressure. For any given partial pressure the material is perfused with the vapour until a state of equilibrium has been achieved. For example the quantification of carbonates in tooth enamel. Environmental carbonates have been shown to be substituted into tooth apatite crystals at phosphate or hydroxyl groups. A high carbonate to-phosphate ratio result in enamel that is particularly susceptible to acid attack (Sobel A.E. Dietary Phosphate and Caries Susceptibility, Dent Prog 2:48-52, 1962).
Contract Research for the Oral Healthcare Industry.
Taylor Aris dispersion
Taylor Aris dispersion is a way of measuring the diffusion coefficient of ions and solvated molecules in a solvent. This is particularity useful in the oral healthcare industry where it is important to optimise the rate of delivery of an active. For example, the rate at which potassium ions reach a target nerve receptor to alleviates the pain of hypersensitivity is governed by many things. One of which is the counter ion associated with the potassium ion. A larger counter ion, or more accurately, a larger hydrodynamic radius may give rise to slower diffusion. A way to measure the the rate of diffusion is to determine the diffusion coefficient and hydrodynamic radius of the ion passing through the solvent system. Taylor Aris dispersion is a relatively simple device where a solvent is passed down a long coil of capillary tubing, often 50 to 100 microns in diameter, and 10 or 20 meters in length. At one end of the tube is a Rheodyne injection valve and the other is a detector (often a uv spectrophotometer). A solvent is pumped at a constant rate and the solution of interest is introduced into the solvent stream with the Rheodyne valve to minimise turbulence. As the solute passes along the capillary tubing, it is acted on by two forces of interest: Convection due to laminar flow of the solvent where the rate at the centre of the tube is faster than at the walls, figure 1, and axial spreading due to radial diffusion, figure 2. Axial spreading is where high concentration at the centre of the solvent face diffuses to lower concentrations towards the capillary wall, slowing down the the front end of the solute plug. At the other end, high concentrations at the capillary wall diffuse to faster moving low concentration at the centre, speeding up the rear end of the solute plug, see figure 1.
The resulting concentration profile that is detected at the end of the capillary tube should look similar to the graph below, and from it the diffusion coefficient and hydrodynamic radius of the solute molecule can be determined.
Contract Research for the Oral Healthcare Industry.
Taylor Aris dispersion is a way of measuring the diffusion coefficient of ions and solvated molecules in a solvent. This is particularity useful in the oral healthcare industry where it is important to optimise the rate of delivery of an active. For example, the rate at which potassium ions reach a target nerve receptor to alleviates the pain of hypersensitivity is governed by many things. One of which is the counter ion associated with the potassium ion. A larger counter ion, or more accurately, a larger hydrodynamic radius may give rise to slower diffusion. A way to measure the the rate of diffusion is to determine the diffusion coefficient and hydrodynamic radius of the ion passing through the solvent system. Taylor Aris dispersion is a relatively simple device where a solvent is passed down a long coil of capillary tubing, often 50 to 100 microns in diameter, and 10 or 20 meters in length. At one end of the tube is a Rheodyne injection valve and the other is a detector (often a uv spectrophotometer). A solvent is pumped at a constant rate and the solution of interest is introduced into the solvent stream with the Rheodyne valve to minimise turbulence. As the solute passes along the capillary tubing, it is acted on by two forces of interest: Convection due to laminar flow of the solvent where the rate at the centre of the tube is faster than at the walls, figure 1, and axial spreading due to radial diffusion, figure 2. Axial spreading is where high concentration at the centre of the solvent face diffuses to lower concentrations towards the capillary wall, slowing down the the front end of the solute plug. At the other end, high concentrations at the capillary wall diffuse to faster moving low concentration at the centre, speeding up the rear end of the solute plug, see figure 1.
Taylor Aris dispersion
The resulting concentration profile that is detected at the end of the capillary tube should look similar to the graph below, and from it the diffusion coefficient and hydrodynamic radius of the solute molecule can be determined.
Human dentine discs treated with a test formulation are then fractured in such a way so that the cross section of the tubules can be imaged running from the treated face to the opposite face
Human dentine discs treated with a test formulation are then fractured in such a way so that the cross section of the tubules can be imaged running from the treated face to the opposite face
In the example below GVS has been used to quantify carbonates in bovine enamel. Hydroxyapatite molecular structure lends itself to a variety of chemical modifications. Environmental circumstances influence the chemical composition at any given time. These chemical changes translate to physical changes such as crystal hardness and resistance to acid attack. Carbonates adsorbed into enamel at high concentration (2-4%) have result in enamel that is particularly susceptible to caries. (taken from my presentationat the British Society for Oral and Dental Research BSODR, Shefild, 2013).
Carbonate loss when bovine enamel is treated with perchloric acid.
Variation of carbonate levels in bovine enamel sourced from two different locations. A=Wales B=Surrey.
Contract Research for the Oral Healthcare Industry.
In the example below GVS has been used to quantify carbonates in bovine enamel. Hydroxyapatite molecular structure lends itself to a variety of chemical modifications. Environmental circumstances influence the chemical composition at any given time. These chemical changes translate to physical changes such as crystal hardness and resistance to acid attack. Carbonates adsorbed into enamel at high concentration (2-4%) have result in enamel that is particularly susceptible to caries. (taken from my presentationat the British Society for Oral and Dental Research BSODR, Shefild, 2013).
Variation of carbonate levels in bovine enamel sourced from two different locations. A=Wales B=Surrey.
Contract Research for the Oral Healthcare Industry.
Measurements of enamel gloss is often combined with the automated brushing machine. A dentifrice is brushed onto enamel specimens over extended time periods and the effects on tooth gloss measured with a glossometer.
Contract Research for the Oral Healthcare Industry.
Enamel gloss testing
Measurements of enamel gloss is often combined with the automated brushing machine. A dentifrice is brushed onto enamel specimens over extended time periods and the effects on tooth gloss measured with a glossometer.
Contract Research for the Oral Healthcare Industry.
Based on the US Food and Drug Administrator (FDA) method #40. Enamel specimens undergo a 10 day incubation in a lactic acid / methylcelulose gel system to form caries lesions. The enamel lesions are then treated with a test formulation containing fluoride over a defined treatment period. Any fluoride that has been incorporated into the enamel is then extracted with perchloric acid and assayed to determine the quantity of fluoride and the extraction volume measured by profilometry.Alternative a more detailed fluoride uptake profile can be obtained by measuring the alkali soluble fluoride concentration (loosely associated fluoride as CaF2 surface deposits) and structurally bound fluoride in fluroapatite species.Alkali soluble fluoride analysed using the method by Caslavska, 1975, Arch Oral Biol. 20(5-6): 333-9.Acid soluble fluoride analysed using the method by Caslavska, 1975, Arch Oral Biol. 20(5-6): 333-9.
Picture of lesions
Contract Research for the Oral Healthcare Industry.
Enamel fluoride uptake
Based on the US Food and Drug Administrator (FDA) method #40. Enamel specimens undergo a 10 day incubation in a lactic acid methylcelulose gel system to form caries lesions. The enamel lesions are then treated with a test formulation containing fluoride over a defined treatment period. Any fluoride that has been incorporated into the enamel is then extracted with perchloric acid and assayed to determine the quantity of fluoride and the extraction volume measured profilometry.Alternative a more detailed fluoride uptake profile can be obtained measuring the alkali soluble fluoride concentration (loosely associated fluoride as CaF2 surface deposits) and structurally bound fluoride fluroapatite species.Alkali soluble fluoride analysed using the method by Caslavska, 1975, Arch Oral Biol. 20(5-6): 333-9.Acid soluble fluoride analysed using the method by Caslavska, 1975, Arch Oral Biol. 20(5-6): 333-9.
Picture of lesions
Contract Research for the Oral Healthcare Industry.
A test formulation applied to a pig tongue section is incubated for a defined time period after which it is rinsed off. Artificial saliva is then added to the holding chamber and the concentration of the active measured over a set time period. Finally the tongue is digested with perchloric acid to release any of the remaining active.
Contract Research for the Oral Healthcare Industry.
The release of actives from soft tissue
The release of actives from soft tissue
A test formulation applied to a pig tongue section is incubated for a defined time period after which it is rinsed off. Artificial saliva is then added to the holding chamber and the concentration of the active measured over a set time period. Finally the tongue is digested with perchloric acid to release any of the remaining active.
Contract Research for the Oral Healthcare Industry.
The treatment for intrinsic staining is usually performed by a dentist using veneers or similar. Extrinsic staining there are a number of different approaches.1.Bleaching products. Most common is peroxide formulations, low dose for home use or a much higher dose for application by a dentist.2.Chemical stain removal. Typically STP (sodium tripoly phosphate) and other poly phosphates.
Contract Research for the Oral Healthcare Industry.
A1 - A4 Red to Brown shadesB1 - B4 Red to Yellow shadesC1 - C4 Grey shadesD1 - D4 Red to Grey shades
Tooth whitening
The treatment for intrinsic staining is usually performed by a dentist using veneers or similar. Extrinsic staining there are a number of different approaches.1.Bleaching products. Most common is peroxide formulations, low dose for home use or a much higher dose for application by a dentist.2.Chemical stain removal. Typically STP (sodium tripoly phosphate) and other poly phosphates.
Contract Research for the Oral Healthcare Industry.
VITA 3-D tooth colour shade guide covers the entire spectrum of tooth colour shades that are found in natural teeth and is based on a three dimensional logical organisation of tooth colours.
A1 - A4 Red to Brown shadesB1 - B4 Red to Yellow shadesC1 - C4 Grey shadesD1 - D4 Red to Grey shades
3.Mechanical removal by high abrasive materials. Tooth creams and some toothpastes with highly abrasive ingredients.The first home whitening kits containing peroxide that came on the market were a great success and so have been joined by many other companies. VITA 3-D tooth colour shade guide covers the normal spectrum of tooth colour shades that are found in natural teeth and is based on a three dimensional logical organisation of tooth colours.The colour shades are:
Contract Research for the Oral Healthcare Industry.
Fluorescence measurements made on sound enamel can be compared to fluorescence measurements on damaged, demineralised or carious enamel. The change in fluorescence is directly proportional to the amount of calcium minerals in the enamel.
In the first example an erosive lesion has been formed on a disc of bovine tooth enamel by exposing the surface to supermarket orange juice for ten minutes. The erosive lesion can be seen in the example below below as a dark square in the middle of the green disc of enamel. (QLF shines blue light onto the enamel which then fluoresces in the green spectrum). Periodically, the erosive lesion is treated by spaying it with Toothboost and then incubation in artificial saliva. Over time the erosive lesion is seen to reminerailise and is eventually repaired back to sound enamel.
In this second example a caries lesion has been formed on a human molar using a lactic acid methylcellulose gel system. Thelesion is seen in the example below as a dark diamond shape on the tooth crown. The lesion was then treated as follows:1. The lesion was treated with a single spray of Toothboost.2. The molar was then placed into an acidic buffer for one hour at room temperature.3. It was then placed into artificial saliva for five minutes. 4. This cycling procedure was repeated approximately five time a day.5. Over night the molar was rested in artificial saliva at room temperature.6. At the start of each day the molar was imaged by QLF and a selection are shown in the slide show below.
Quantitative light induced fluorescence
Contract Research for the Oral Healthcare Industry.
Fluorescence measurements made on sound enamel can be compared fluorescence measurements on damaged, demineralised or carious enamel. The change in fluorescence is directly proportional to the amount of calcium minerals in the enamel.
In the first example an erosive lesion has been formed on a disc of bovine tooth enamel by exposing the surface to supermarket orange juice for ten minutes. The erosive lesion can be seen in the example below below as a dark square in the middle of the green disc of enamel. (QLF shines blue light onto the enamel which then fluoresces in the green spectrum). Periodically, the erosive lesion is treated by spaying it with Toothboost and then incubation in artificial saliva. Over time the erosive lesion is seen to reminerailise and is eventually repaired back to sound enamel.
In this second example a caries lesion has been formed on a human molar using a lactic acid methylcellulose gel system. Thelesion is seen in the example below as a dark diamond shape on the tooth crown. The lesion was then treated as follows:1. The lesion was treated with a single spray of Toothboost.2. The molar was then placed into an acidic buffer for one hour at room temperature.3. It was then placed into artificial saliva for five minutes. 4. This cycling procedure was repeated approximately five time a day.5. Over night the molar was rested in artificial saliva at room temperature.6. At the start of each day the molar was imaged by QLF and a selection are shown in the slide show below.
Contract Research for the Oral Healthcare Industry.
An example of a block of enamel that has been subjected to acid erosion. The square “well” was formed by protecting the surrounding enamel with tape and application of 1% citric acid solution. Over time the well is formed as the underlying enamel is dissolved.
See “On the dissolution of hydroxyapatite”
An example of a block of enamel that has been subjected to acid erosion. The square “well” was formed by protecting the surrounding enamel with tape and application of 1% citric acid solution. Over time the well is formed as the underlying enamel is dissolved.
Contract Research for the Oral Healthcare Industry.
Hydraulic conductance fluid flow rates are measured at Modus Laboratories using an adaptation of the Pashley hydraulic conductance model. Human dentine discs are placed into a specialised cell and orientated so that fluid can be passed through the tubules in the dentine that run from from one side to the other. The measurement of the rate and volume of fluid flow can be used to assess the effectiveness of treatments applied to the dentine that aim to block the tubule and so reduce fluid flow.
Hydraulic conductance measurements
Human dentine surface imaged by scanning electron microscopy at 5000x magnification.
A cross-section through a single tubule and imaged by SEM at 20,000x magnification.
Contract Research for the Oral Healthcare Industry.
The surface of human dentine imaged by SEM at 2000x magnification.
The hydraulic conductance device consist of a pressurised vessel containing a liquid that will perfuse through a disc of dentine. The pressure in the vessel is carefully regulated so that the liquid will flow out at a constant pressure and passes through a liquid flow meter. From there it goes through a split cell that contains a disc of dentine. The manufacturing quality of the dentine disc is a crucial part of the procedure in that it should be cut so that there is approximately 1cm diameter of perfectly intact dentine with no pin holes or imperfections and with an abundance of patent tubules orientated from one face to the other. The disc is then sealed in the split cell so there is no air locks or leakage. The flow of liquid through the dentine is then measured and can be treated and remeasured to determine the extent of tubule occlusion. Various degrees of complexity can be built into this model to mimic a daily brushing routine.
Hydraulic conductance fluid flow rates are measured at Modus Laboratories using an adaptation of the Pashley hydraulic conductance model. Human dentine discs are placed into a specialised cell and orientated so that fluid can be passed through the tubules in the dentine that run from from one side to the other. The measurement of the rate and volume of fluid flow can be used to assess the effectiveness of treatments applied to the dentine that aim to block the tubule and so reduce fluid flow.
Hydraulic conductance measurements
A cross-section through a single tubule and imaged by SEM at 20,000x magnification.
Contract Research for the Oral Healthcare Industry.
Contract Research for the Oral Healthcare Industry.
Potassium flux is the measurement of rate and quantity of potassium ions passing through dentine tubules. A disc of human dentine is placed into a specialised cell and orientated so that fluid can be passed through the tubules in the dentine that run from from one side of the dentine disc to the other. A flow of liquid passing underneath the dentine disc is directed through the dentine disc causing back pressure that is opposing a potassium treatment applied onto the top face of the dentine disc. The diffusing potassium ions are therefore diffusing into an opposing stream of liquid. The aim of the experiment is to mimic thein vivo situation where a treatment applied to exposed dentine is subjected to an outward flow of papal fluid. This is the bases of the Pashley model for measurement of potassium diffusion.
Potassium flux measurements
Contract Research for the Oral Healthcare Industry.
Potassium flux is the measurement of rate and quantity of potassium ions passing through dentine tubules. A disc of human dentine is placed into a specialised cell and orientated so that fluid can be passed through the tubules in the dentine that run from from one side of the dentine disc to the other. A flow of liquid passing underneath the dentine disc is directed through the dentine disc causing back pressure that is opposing a potassium treatment applied onto the top face of the dentine disc. The diffusing potassium ions are therefore diffusing into an opposing stream of liquid. The aim of the experiment is to mimic thein vivo situation where a treatment applied to exposed dentine is subjected to an outward flow of papal fluid. This is the bases of the Pashley model for measurement of potassium diffusion.
Based on ASTM E384, Vickers and Knoop micro indentation, measurements are made using either a square based pyramid indenter (Vickers hardness) or an elongated, rhomboidal shaped indenter (Knoop hardness). The micro-indenter applies test load, typically, 0.2N and the dimensions of the impressions are precisely measured with a microscope. A hardness number is then calculated using the test load and the impression dimensions.
Vickers indenter
Knoop indenter
Contract Research for the Oral Healthcare Industry.
Micro-indentation measurements
measurements are made using either a square based pyramid indenter (Vickers hardness) or an elongated, rhomboidal shaped indenter (Knoop hardness). The micro-indenter applies test load, typically, 0.2N and the dimensions of the impressions are precisely measured with a microscope. A hardness number is then calculated using the test load and the impression
Vickers indenter
Knoop indenter
Contract Research for the Oral Healthcare Industry.
Screening of anti-calculus actives using an in vitro model which involves growing of plaque in a bacterial broth and mineralising to form calculus. Treatments can be rapidly screened to measure their propensity to inhibit plaque and subsequent calculus formation.
Contract Research for the Oral Healthcare Industry.
Calculus prevention
Screening of anti-calculus actives using an in vitro model which involves growing of plaque in a bacterial broth and mineralising to form calculus. Treatments can be rapidly screened to measure their propensity to inhibit plaque and subsequent calculus formation.
Contract Research for the Oral Healthcare Industry.
We have an extensive collection of formulation and development equipment for small scale batch manufactureof toothpastes, creams, jells, mouthwashes etc for proof of concept, stability testing and prototype visualisation.We are the formulators for Dentherapy’s Toothboost a remineralising spray.
We have stability cabinets and stability testing equipment. With our close partnership with Reading University analytical department we have access to specialised equipment such as: NMRCalorimetryGC-MSGC-OlfactometryHPLCLC-MS Ion TrapCapillary ElectrophoresisIon Chromatography
