Patent Application
20230053073
This invention generally relates to dental systems and cosmetic treatments and, more particularly but not exclusively, to systems and methods a synergistic laser cleaning and whitening of teeth.
Research has long showed the ability of some lasers to make dental hard tissue (e.g., enamel) less susceptible to acidic dissolution. For example, in 1998, J. Featherstone et al. demonstrated inhibition of caries progression ranging from 40% to 85% after irradiation with infrared laser sources in an article entitled “CO2 Laser Inhibitor of Artificial Caries-Like Lesion Progression in Dental Enamel,” published in the Journal of Dental Research and incorporated herein by reference. These results have been corroborated and repeated throughout the years. Another notable project involved researchers from University of California San Francisco and Indiana University both evaluating laser treatment for caries-inhibition in different intra-oral models. The project was documented in an article entitled “Effect of Carbon Dioxide Laser Treatment on Lesion Progression in an Intraoral Model,” published in 2001 in Proc. SPIE by J. Featherstone et al. and incorporated herein by reference.
A mechanism that is believed to contribute to this inhibition of acid dissolution of laser treated hard tissue is carbonate removal. Human dental enamel is primarily (96%-wt %) comprised of hydroxyapatite (HA). Specifically, the HA found in dental enamel is non-stoichiometric carbonate-substituted hydroxyapatite (Ca10(PO4)6−x(OH)2−y)(CO3)x+y, where 0≤x≤6, 0≤y≤2, which contains trace amounts of fluoride (F), sodium (Na), magnesium (Mg), zinc (Zn) and strontium (Sr)), as reported by C. Xu et al., in an article published in 2014 in J. Material Sci., entitled “The Distribution of Carbonate in Enamel and its Correlation with Structure and Mechanical Properties,” incorporated herein by reference. Xu et al. describe that increases in carbonate content within enamel correlate with decreases in mechanical properties, for example crystallinity, modulus, and hardness. It has also been long reported that increased carbonate content within enamel correlates with an increased susceptibility to acid. For example, J. Featherstone et al. reported in “Mechanism of Laser-Induced Solubility Reduction of Dental Enamel,” first published in SPIE Proc. in 1997, and incorporated herein by reference, that carbonate removal from enamel correlates to increased resistance to caries, with complete carbonate removal correlating with the optimum resistance to caries. Caries are formed through acid dissolution. Removal of carbonate within dental enamel is achieved through elevating a temperature of the enamel.
The temperature range required for removing carbonate from dental tissue has long been taught, for example by Zuerlein et al. in an article published in 1999 in Lasers in Surgery and Medicine, entitled “Modeling the Modification Depth of Carbon Dioxide Laser-Treated Dental Enamel,” incorporated herein by reference. Zuerlein et al. found that carbonate loss began when enamel reached temperatures in excess of about 400° C. during laser irradiation, but complete carbonate removal was not achieved until the enamel reached its melting point. The melting point of dental enamel is about 1280° C. as reported by Fried et al. in an article published in 1998 in Applied Surface Science entitled “IR Laser Ablation of Dental Enamel: Mechanistic Dependence on the Primary Absorber,” incorporated herein by reference. For over 20 years it has been known to the dental research community that momentarily elevating a temperature of dental enamel to a temperature in a range between about 400° C. and about 1300° C. will reduce carbonate content and increase the enamel's resistance to acid (e.g., caries and erosion).
Additional research has shown that preventative dental laser treatment can be improved upon with application of a fluoride treatment following laser treatment. For example, referring to “Non-Destructive Assessment of Inhibition of Demineralization in Dental Enamel Irradiated by a λ=9.3-μm CO2 Laser at Ablative Irradiation Intensities with PS-OCT,” published in Lasers in Surgery and Medicine in 2008, incorporated herein by reference, A. Can et al. present a statistically significant improvement in inhibition of demineralization of dental enamel for bovine enamel surfaces treated with both laser and fluoride over bovine enamel surfaces treated with laser alone. While the results of the scientific research have shown great promise for over 20 years, commercialization and adoption of this technology has not occurred anywhere in the world.
A commercial impediment to the wider adoption of this technology is slow adoption of new technologies in dentistry and the concomitant modest-to-low level of enthusiasm for investment and commercialization in high tech dental products. A reason that explains the relatively slow adoption of new technologies in dentistry is the fact that most dentists run their own practices. The dentist, as the owner of the dental practice, is unwilling in many cases to expend resources for the latest technological advancement, when those resources can be used on other (often times personal) expenses. Additionally, most technological advances require a change in workflow for the dentist. As the owner of the practice, the dentist is not often compelled to change the way she works (i.e., workflow), unless she decides to do so. A desire on the part of the dentist to not fix what isn't broken explains the slow adoption of many high technology dental products. The slow adoption of new dental technologies is also recognized in the area of professional investment. For example, although there are many professional investment groups that focus on medical devices, there are none in the United States that focus on dental devices. A mixed cause-and-result of this environment is that few new high-tech solutions reach and penetrate the dental market.
This commercial impediment is amplified by the reality that few people really prioritize their oral health. J.P. Morgan famously quipped that “A man always has two reasons for doing anything: a good reason and the real reason.” So, it is with oral health. Seldom is oral health the real reason, people take care of their teeth. Rory Sutherland, in Alchemy, published in 2019, extrapolates that the huge benefits in oral health attained by fluoride toothpaste were achieved, not because individuals valued oral health, but because they valued good smelling breath.
It would seem that the most important oral health activity (brushing one's teeth) is motivated by both a good reason—improved oral health and a real reason—improved smelling breath. While science shows without equivocation that a good reason exists for preventive dental laser treatment, there has been no real reason for the dental market to embrace it.
Systems and methods for preventative dental laser treatment have been known to science for decades. However, the known state-of-the-art (including all of the above-mentioned references) fail to teach a way for the treatments to be made attractive to a dental market that is notoriously slow to adopt high tech solutions and a larger public whose interest in oral health is largely confined to fleeting moments sitting in the dentist's chair. In order for dental patients to benefit from decades of scientific breakthroughs in preventative dental laser treatments, laser systems and methods must be developed that are adopted by dental offices and desirable to the dental market.
Preventative laser treatment technology has been known by researchers for almost 30 years to increase caries-resistance of treated teeth up to tenfold. * †‡. But the technology has never successfully been commercialized or improved the quality of life for a single dental patient (outside of clinical studies). The applicant believes the reasons for this are, in large part, outlined above and generally relate to motivations of industry stakeholders (e.g., dentists, patients, and businessmen) and to the dental industry environment in general. To bring this promising technology to market, aspects of the present invention relate not only to new technical variations for methods and systems of treatment, but applications of this technology to treat teeth in a manner never before attempted, but expected to be widely popular. At least for this reason, embodiments of the present invention relate to improving the rate of teeth whitening by first removing pellicle from the surface of the teeth with a laser. Just as Rory Sutherland has pointed out that many people are seemingly motivated to brush their teeth in order to have good smelling breath and appreciate the oral benefits of brushing secondarily, the applicant submits that many patients will elect dental laser treatment to whiten and improve the aesthetic qualities of their teeth and benefit from the known anticavity benefits of laser treatment secondarily.
As mentioned above, high-tech solutions are viewed as slow to be adopted in the dental market and professional investors eschew the opportunity to invest in high-tech dental solutions. However, an exception exists in the aesthetic dental market. Countless laser, white light, and UV whitening devices have been developed and entered into the dental market in the past 10 years. Although, the performance of these systems is modest and in some cases the claims of these systems are exaggerated, their presence in the market demonstrates an acceptance for high-tech dental solutions that promise aesthetically pleasing outcomes. University research exclusively describes preventative CO2 laser treatment as an anti-cavity procedure, which is applied to small at-risk portions of teeth (e.g., pits and fissures). However, embodiments of the present invention relate to systems and methods that can be used to aid in whitening teeth.
Commonly, at every dental cleaning the patient is treated with scaling of the dental hard tissue with metal picks (e.g., scalers and explorers), as well as dental prophylaxis. The reason for these procedures is, in part, to remove biofilm (e.g., tartar and plaque) that builds up on teeth. Exemplary embodiments described herein selectively remove biofilm from the teeth with touchless, sensationless laser procedure. Unlike, with the mechanical methods described above, removal of biologics using a laser leave no smear layer. The teeth after laser treatment are pristine and free from the protective pellicle that normally protects the enamel, allowing for the direct application of a synergistic whitening treatments to the exposed enamel. Direct application of the whitening composition to a pristine tooth surface in some cases, is further improved upon by use of light assisted whitening, which additionally accelerates the whitening process.
In one aspect, a system for synergistic laser cleaning and whitening of teeth includes a laser system configured to perform a laser treatment on exposed tooth surfaces on a plurality of a patient's teeth, where the laser system includes a laser arrangement configured to generate a laser beam, an optical arrangement configured to direct the laser beam toward the exposed tooth surfaces, and a laser controller configured to control the laser beam to remove a pellicle from the exposed tooth surfaces, and a tray configured to apply a whitening agent to the exposed tooth surfaces after the laser treatment.
In another aspect, a method of synergistic laser cleaning and whitening of teeth includes performing, using a laser system, a laser treatment on exposed tooth surfaces on a plurality of a patient's teeth, where the laser treatment includes generating, using a laser arrangement, a laser beam, directing, using an optical arrangement, the laser beam toward the exposed tooth surfaces, and controlling, using a laser controller, the laser beam to remove a pellicle from the exposed tooth surfaces, applying, using a tray, a whitening agent to the exposed tooth surfaces within a certain post-laser time after the laser treatment, such that the composition directly wets the exposed tooth surfaces, after the pellicle has been removed, and maintaining, using the tray, application of the whitening agent to the exposed tooth surfaces for a prescribed whitening duration.
Any combination and permutation of embodiments is envisioned. Other objects and features will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the present disclosure.
Non-limiting and non-exhaustive embodiments of the invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.
The drawings are not necessarily to scale and may be illustrated by phantom lines, diagrammatic representations and fragmentary views. In certain instances, details that are not necessary for an understanding of the embodiments or that render other details difficult to perceive may have been omitted.
Various embodiments are described more fully below with reference to the accompanying drawings, which form a part hereof, and which show specific exemplary embodiments. However, the concepts of the present disclosure may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided as part of a thorough and complete disclosure, to fully convey the scope of the concepts, techniques and implementations of the present disclosure to those skilled in the art. Embodiments may be practiced as methods, systems or devices. Accordingly, embodiments may take the form of a hardware implementation, a complete software implementation or an implementation combining software and hardware aspects. The following detailed description is, therefore, not to be taken in a limiting sense.
Reference in the specification to “one embodiment” or to “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one example implementation or technique in accordance with the present disclosure. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
Some portions of the description that follow are presented in terms of symbolic representations of operations on non-transient signals stored within a computer memory. These descriptions and representations are used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. Such operations typically require physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical, magnetic or optical signals capable of being stored, transferred, combined, compared and otherwise manipulated. It is convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. Furthermore, it is also convenient at times, to refer to certain arrangements of steps requiring physical manipulations of physical quantities as modules or code devices, without loss of generality.
However, all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system memories or registers or other such information storage, transmission or display devices. Portions of the present disclosure include processes and instructions that may be embodied in software, firmware or hardware, and when embodied in software, may be downloaded to reside on and be operated from different platforms used by a variety of operating systems.
The present disclosure also relates to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, application specific integrated circuits (ASICs), or any type of media suitable for storing electronic instructions, and each may be coupled to a computer system bus. Furthermore, the computers referred to in the specification may include a single processor or may be architectures employing multiple processor designs for increased computing capability.
The processes and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may also be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform one or more method steps. The structure for a variety of these systems is discussed in the description below. In addition, any particular programming language that is sufficient for achieving the techniques and implementations of the present disclosure may be used. A variety of programming languages may be used to implement the present disclosure as discussed herein.
In addition, the language used in the specification has been principally selected for readability and instructional purposes and may not have been selected to delineate or circumscribe the disclosed subject matter. Accordingly, the present disclosure is intended to be illustrative, and not limiting, of the scope of the concepts discussed herein.
Referring now to
In some embodiments, energy source 114 may include a metal-air battery, such as without limitation a zinc-air battery. A metal-air battery is an electrochemical cell that uses an anode made from pure metal and an external cathode of ambient air, often with an aqueous or aprotic electrolyte. As a metal-air battery discharges, a reduction reaction occurs in the ambient air cathode while the metal anode is oxidized. In many cases, specific capacity and energy density of metal—air electrochemical cells are higher than that of lithium-ion batteries. In some cases, zinc-air batteries are metal—air batteries powered by oxidizing zinc with oxygen from air. These batteries have high energy densities and are relatively inexpensive to produce. Sizes range from very small button cells, such as without limitation those for hearing aids, larger batteries, such as those used in film cameras, to very large batteries, such as those used for electric vehicle propulsion and grid-scale energy storage.
In some embodiments, during discharge of a zinc-air battery, a mass of zinc particles forms a porous anode, which is saturated with an electrolyte. In some cases, oxygen from the air reacts at a cathode and forms hydroxyl ions which migrate into the zinc paste and form zincate (Zn(OH)42−), releasing electrons to travel to the cathode; in some cases, as the zincate decays into zinc oxide, water returns to the electrolyte. In some embodiments, the water and hydroxyl from the anode are recycled at the cathode, so the water need not be consumed. In some cases, zinc-air battery reactions produce a theoretical 1.65 volts, however in practice zinc-air batteries achieve about 1.25-1.5 volts.
With continued reference to
With continued reference to
In some embodiments, the tray 100 includes a light source, 116. The light source 116, in some cases, includes one or more light emitting diodes 116. Alternatively, the lights source 116 can include any source of light, for example a laser, a light emitting capacitor, any coherent light source or non-coherent light source. In some cases, the light source 116 has a wavelength within at least one specified range. Exemplary non-limiting wavelength ranges including UV wavelengths, visible wavelengths, near-infrared wavelengths, infrared wavelengths, and the like. In some cases, the light source 116 has wavelength within a photoactivating wavelength range, believed to expedite whitening, for example a wavelength having a shorter high-energy wavelength, such as without limitation UV and/or blue wavelength for instance wavelengths below about 500 nm and above about 100 nm. An exemplary non-limiting light source include a 450 nm wavelength LED, e.g., Thorlabs Part No. LEDS450, from Thorlabs of Newton, N.J. The LEDS450 has a center wavelength of 450 nm, a bandwidth of 13 nm (FWHM), a viewing half angle of 46°, a DC forward current (Maximum) of 180 mA, a forward voltage (Maximum) of 6.6V, an emitter size of 1 mm×0.5 mm, two emitters, and an expected minimum lifetime greater than 25,000 hours.
In some embodiments, light source 116 has a wavelength within a photobiomodulation (PBM) wavelength range. In some cases, the PBM wavelength range include one or more of ultraviolet, visible, and/or infrared light. In some cases, light source 116 illuminates a PBM wavelength with a prescribed PBM dosage. In some case, PBM has a multi-phasic (e.g., biphasic) dosage response, which is explained in greater detail in reference to
Photobiomodulation, which is at times referred to as low level light (or laser) therapy (LLLT), can act according to a biphasic (i.e., hormesis) dose-response relationship. Hormesis dose-responses can be understood as following the Arndt-Scholz rule of pharmacology: “For every substance, small doses stimulate, moderate doses inhibit, and large doses kill.” Thus, a hormesis dose-response can be modeled using an Arndt-Schulz curve.
Exemplary PBM wavelengths are enumerated in a table below:
Exemplary PBM light dosages are enumerated below:
Referring to
An exemplary system 400 is shown in
In accordance with one embodiment, the system 400 is used by a clinician. First, the clinician inputs operating parameters into the user interface 412, for example by using a touch screen. Then the clinician places the hand piece 416 within a patient's mouth and directs the hand piece 416 toward dental hard tissue. For example, the clinician positions the hand piece 416 so that a focal region of the laser beam is coincident with or near (e.g., +/−1 mm, 2 mm, 3 mm, or 5 mm) a surface of a tooth. Then, the clinician activates the laser by stepping on a foot pedal 418. The clinician moves the hand piece 416 within the patient's mouth, carefully directing the focal region of the laser beam near every treatment surface of the patient's teeth.
Referring to
Thermal relaxation time is defined, in some cases, to represent an estimated amount of time required for thermal diffusion to reduce temperature in a layer of dental tissue, having a certain thickness, by approximately one half. Commonly, the thickness of the layer of dental tissue is taken to be an optical penetration depth, which is approximated as an inverse of the absorbance coefficient of the laser radiation in dental tissue, or:
where, X(λ) is the optical penetration depth as a function of wavelength, A is wavelength of the laser, and μa(λ) is the absorption coefficient of dental tissue at the laser wavelength. The thermal relaxation time, or time for a temperature required for tissue at a certain depth to reach about 84% of a surface temperature, is approximated as:
where, t is the thermal relaxation time, x is the depth of the location of the tissue, and K is a thermal diffusivity of the tissue (e.g., enamel, dentine, or cementum). In some cases, it is appropriate to calculate an axial (depth orientated) thermal relaxation time, as described above and (by using the optical penetration depth as x). Alternatively, it is appropriate to calculate a radial thermal relaxation time that represents an amount of time for tissue radially displaced from the laser beam to heat as a result of pulsed laser cooling (by using a width of the laser beam as x). In many cases, the laser beam width is larger than the optical penetration depth and as a result the shorter of the two thermal relaxation times (axial and radial) is the axial thermal relaxation time. Thermal diffusivity is given as:
where, K is the thermal diffusivity (for example, in units of m2/s, k is thermal conductivity (for example, in units of W/[mK]), ρ is density (for example, in units of kg/m3), and cp is specific heat capacity (for example, in units of J/[kgK]). Exemplary thermal parameters for dental enamel include, a density of about 2.9 g/cm3, a specific heat capacity of about 0.75 J/(g° C.), a thermal conductivity of about 9.2×10−3 W/(cm° C.), and a thermal diffusivity of about 0.0042 cm2/s. Exemplary thermal relaxation times for dental enamel with a 10.6 micron and 9.6 micron laser are about 1 μs and about 90 μs, respectively.
The laser beam is directed to exposed dental surfaces 512. Exposed dental surfaces comprise all tooth surfaces in the mouth, including buccal surfaces, facial surfaces, palatal surfaces, lingual surfaces, occlusal surfaces, interproximal surfaces, mesial surfaces, and distal surfaces. Generally, all tooth surfaces in the mouth have a salivary pellicle formed upon them. This pellicle layer (i.e., biofilm) is formed from proteins and glycoproteins in saliva. Under normal oral conditions, the pellicle layer protects the underlying tissue surface (i.e., enamel, dentin, or cementum). For example, the pellicle protects the dental tissue from direct exposure to acids, such as those formed by bacteria or those ingested by the patient. The pellicle is also normally colonized by bacteria (e.g., gram positive aerobic cocci, such as Streptococcus sanguins, Streptococcus mutans, and Lactobacilli). Because the pellicle covers and protects the dental surfaces, it also prevents dental surfaces from being directly exposed to any number of compositions that are being employed to bring about a desired effect. For example, some tooth whitening procedures first instruct the patient to brush her teeth with a weak acid formulation to break down the pellicle, before applying the whitening (e.g., hydrogen peroxide) composition to whiten her teeth. Brushing one's teeth with acid is not a daily routine that most would consider healthy or anti-aging for teeth, but it increases the speed of effective whitening treatment by allowing the enamel to be directly wetted by the whitening composition.
In some cases, the treatment is performed especially on aesthetic enamel surfaces (i.e., enamel surfaces that are visible when the patient smiles fully). Alternatively, in some cases, the treatment is performed on most or nearly all (e.g., greater than 50% or greater than 80%) of enamel surfaces. In some embodiments, the laser beam is directed into an intra-oral cavity using a beam delivery system. The laser beam is often directed within the intra-oral cavity using a hand piece. In some embodiments, the laser beam is converged, using a focus optic, as it is directed toward the dental hard tissue, such that it comes to a focal region proximal the surface of the dental hard tissue. Exemplary focus optics include lenses (e.g., Zinc Selenide Plano-Convex lenses having an effective focal length of 200 mm) and parabolic mirrors. In some embodiments, the laser beam is scanned as it is directed toward the surface of the dental hard tissue by a beam scanning system. Exemplary beam scanning systems include Risley prisms, spinning polygon mirrors, voice coil scanners (e.g., Part No. MR-15-30 from Optotune of Dietikon, Switzerland), galvanometers (e.g., Lightning II 2-axis scan head from Cambridge Technology of Bedford, Mass., U.S.A.), and a gantry with a translating focus optic. Scanning methods related to dental laser systems are described in U.S. Pat. No. 9,408,673 by N. Monty et al., incorporated herein by reference.
In some embodiments, a parameter of the laser beam is controlled to affect treatment. Typically, the parameter of the laser beam is controlled in order to heat a portion of the surface of the dental hard tissue to a temperature within a range, for example between about 500° C. and about 1300° C. Exemplary laser parameters include pulse energy, pulse duration, peak power, average power, repetition rate, wavelength, duty cycle, laser focal region size, laser focal region location, and laser focal region scan speed. During laser treatment a laser beam is generated and directed toward a surface of dental hard tissue. Typically, the laser beam is pulsed at a prescribed repetition rate and has a certain pulse duration. Alternatively, pulses can be delivered on demand, and the pulse duration can vary (for example, to control heating of the surface of the dental hard tissue). As a result of the irradiation of the surface, a temperature of the surface rises typically to within a range (e.g., between 400° C. and 1300° C.) momentarily (e.g., during a duration of the laser pulse) and cools back to a normal temperature range (e.g., within a range of 20° C. and 60° C.). As a result of the momentary temperature rise biological materials previously near or adhered to the surface of the dental hard tissue (e.g., pellicle, bio-film, calculus, and tartar) are at least partially removed or denatured. In some embodiments, this removal of biological materials substantially cleans the teeth and the laser treatment replaces other tooth cleaning procedures typically performed during a dental check-up (e.g., scaling and polishing). Additionally, as described above, heating the surface of the dental hard tissue removes impurities (e.g., carbonate) from the dental hard tissue and makes the dental hard tissue less-susceptible to acid dissolution (e.g., demineralization). An exemplary laser energy dosage delivered during a single treatment does not exceed an average power of about 2 W, a treatment time of about 600 seconds, and therefore does not deliver more than about 1200 J of laser energy to the oral cavity. In some embodiments, the laser treatment is performed after other treatments during a dental visit. For example, in some cases the dental laser treatment is performed only after one or more of removal of plaque and tartar (with one or more manual instruments), professional flossing, and power polishing (i.e., dental prophylaxis). This order of steps in some cases is considered advantageous, as the laser treatment purifies only an outer portion (e.g., 2 μm thick) of the dental enamel and some dental cleaning treatments can remove a portion of dental enamel (e.g., power polishing), potentially removing the enamel which has just been purified.
In some exemplary embodiments, in order to perform effective treatment, the enamel surface needs to have its temperature raised momentarily to within an elevated range (e.g., about 400° C. to about 1500° C.). As described throughout, elevating the temperature of enamel changes the chemical composition of hydroxyapatite within the enamel. Dental enamel comprises 96% (wt %) hydroxyapatite, 3% water, and 1% organic molecules (lipids and proteins). Specifically, dental enamel comprises 96% calcium-deficient carbonated hydroxyapatite (CAP), with a chemical formula approximated by Ca10−xNax(PO4)6−y(CO3)z(OH)2−uFu. The ideal chemical formula for hydroxyapatite (HAP), by comparison, is approximated as Ca10(PO4)6(OH)2. The calcium deficiency of dental enamel is shown by the x in Ca10−x. Some of the calcium is replaced by metals, such as sodium, magnesium, and potassium. These metals together total about 1% of enamel. Some of the OH molecules in dental enamel are replaced by F. But, the major difference between CAP and HAP comes with the presence of carbonate. Carbonate comprises between about 2 and about 5% (wt %) of dental enamel. The presence of carbonate within the hydroxyapatite structure disturbs a crystal lattice of the CAP, changing the size and shape of the unit crystal form and resulting in different mechanical and chemical properties between CAP and HAP. Increased carbonate content in enamel correlates with increases in susceptibility to acid and inversely correlates with crystallinity, hardness, and modulus (i.e., stiffness). Said another way the purer HAP erodes (through acid dissolution), wears (through mechanical means), and ages more slowly, compared to CAP.
As has been described in literature, including the Co-owned Int. Patent Appl. No. PCT/US21/15567, entitled “Preventative Dental Hard Tissue Laser Treatment Systems, Methods, and Computer-Readable Media”, by C. Dresser et al., incorporated herein by reference, carbonate can be removed from dental enamel by laser irradiation at prescribed parameters. Specifically, by using a laser source that is well absorbed (e.g., absorbance of at least 500 cm−1) in dental enamel, and heating the surface of the tooth momentarily (e.g., at pulse durations that are no greater than 100× a thermal relaxation time) to a temperature of at least about 400° C., carbonate is driven (e.g., sublimated) from the enamel.
The laser beam, as it is directed to the exposed dental surface, is typically better absorbed by the underlying dental surface (e.g., enamel) than by the pellicle layer. For example, an absorption coefficient of a CO2 laser beam in enamel is 8,000 cm−1, 5,500 cm−1, and 825 cm−1 for 9.3 μm, 9.6 μm, and 10.6 μm wavelengths respectively. § ** For the same 9.3 μm, 9.6 μm, and 10.6 μm wavelengths the absorption coefficient in 100% water is about 600 cm−1 and in 4% water is about 30 cm−1. †† Depending upon a hydration level of the salivary pellicle a nominal to moderate amount of absorption of laser radiation will occur within the pellicle. Conversely, a moderate to very high level of laser radiation occurs within the enamel. In cases of high laser absorption (e.g., absorption coefficient greater than 600 cm−1) in enamel and low laser absorption (e.g., absorption coefficient less than 600 cm−1) in the pellicle, most of the laser energy is absorbed in a surface of the enamel. The laser energy absorbed in the outer surface of the enamel typically occurs in such a narrow width (the width of the laser beam) (e.g., less than 2 mm, less than 1 mm, less than 0.5 mm or less than 0.25 mm) and at such a thin depth (approximated by an optical penetration depth, which is an inverse of the absorption coefficient) (e.g., less than 0.2 mm, less than 0.1 mm, less than 0.02 mm, less than 0.01 mm, less than 0.005 mm, or less than 0.002 mm) that a small amount of energy (e.g., less than 100 mJ, less than 50 mJ, less than 20 mJ, less than 10 mJ, less than 5 mJ, or less than 2 mJ) raises a temperature of the surface of the enamel significantly (e.g., greater than 50° C., greater than 100° C., greater than 200° C., greater than 500° C., greater than 700° C., or greater than 1000° C.) momentarily (e.g., less than 10 ms, less than 1 ms, less than 0.5 ms, or less than 0.1 ms). As a result of this momentary rise of enamel surface temperature, the pellicle layer is removed (e.g., vaporized, sublimated, ablated, or denatured). Unlike other forms of removing the pellicle layer (e.g., dental prophylaxis, acid etching, or abrasion), laser treatment does not risk removal of the enamel, but substantially only the pellicle layer, along with any plaque, tartar or surface contaminants (i.e., biofilm), is removed. In some embodiments, the enamel is raised to a temperature within a first range between about 100° C. and about 400° C. In this first range, the salivary pellicle is substantially removed, but the enamel does not experience any substantial improvements to its mechanical properties (e.g., removal of carbonate, increased crystallinity, increased modulus [i.e., stiffness], increased resistance to acid or increased hardness). In some cases, heating the enamel surface within this first range is advantageous as the pellicle is removed, while the underlying enamel remains receptive to topical compositions (e.g., whiting agents, remineralization agents, and fluoride treatments). Alternatively, in some embodiments, the enamel is raised to a temperature within a second range between about 400° C. and about 1500° C. When heated to a temperature within this second range, the surface of the enamel has the pellicle layer removed and also experiences improvements to its mechanical properties (e.g., removal of carbonate, increased crystallinity, increased modulus [i.e., stiffness], increased resistance to acid, or increased hardness). Heating of enamel to a temperature within this range removes carbonate impurities from within the enamel surface. ‡‡ A lack of carbonate impurities within enamel (i.e., hydroxyapatite) correlates with an increase in mechanical properties, such as crystallinity, modulus, hardness, and resistance to acid. §§ ***
In some embodiments, one or more laser parameters are controlled to control the temperature rise of the dental surface. Exemplary parameters that can be controlled to affect the temperature rise include, pulse duration, pulse energy, repetition rate, fluence, irradiance, peak power, average power, number of overlapping pulses at a given location, and time between pulses (i.e., repletion period). The fluence of the laser at the surface of the enamel is commonly selected to affect a temperature rise of dental enamel. For example, with a 9.3 micron laser and a pulse duration in a range between about 0.1 and about 100 μs, a fluence greater than about 0.5 J/cm′ and less than about 5 J/cm2 causes elevation of enamel surface temperature to within the 400° C. to 1500° C. range. Predictive modeling of effects of laser treatment on surface temperature rise has been found substantially accurate. For example, a nodal finite element analysis using Fourier conduction, Beer's absorption, and Newton's cooling with known parameters has been performed by the applicant. This analysis demonstrated that predictable surface temperature results are attained through use of the model. The model was verified by bench tests with multiple laser sources having peak powers ranging from about 50 W to about 1000 W. Further disclosure related to parameter selection for dental surface temperature rise and nodal-FE analysis for parameter selection is described in detail in U.S. Patent Appl. No. 62/968,910, entitled Laser Delivery of Transverse Electromagnetic Modes for Even Preventative Dental Hard Tissue Treatment, by N. Monty et al., incorporated herein by reference. Predictable temperature rise based upon known thermal and photonic constants allows for the selection and control of parameters to control temperature rise. For example, in some embodiments, a laser parameter is controlled in order to control the temperature rise of a non-enamel dental hard tissue (e.g., dentin, cementum, or osseous tissue) to a range having a lower boundary and an upper boundary. The lower boundary being selected to exceed a denaturing threshold of the biofilm (e.g., at least 50° C. or at least 100° C.). The upper boundary being selected not to exceed a tissue combustion, carbonization, incineration, or melting threshold (e.g., no more than about 200° C., no more than about 400° C., no more than about 600° C., or no more than about 1000° C.).
In some cases, removal of the biofilm completes the laser procedure. Alternatively, in some embodiments, a composition is applied directly to the surface 518, with substantially no pellicle (or biofilm) layer between the composition and the surface. In some embodiments, the direct application of the composition without an intermediary pellicle or biofilm layer improves the efficacy of the composition and, in some cases, allows a decreased dosage (e.g., concentration of active ingredient) of the composition to be used. Exemplary compositions include whiting agents, fluoride treatments, desensitizing agents, remineralization agents, sealants, composite filings, etches, wetting agents, and adhesives.
In some cases, the composition includes a whitening agent. As described above whitening agents are reduced in efficacy by the protective salivary pellicle, which prevents all of the oxidizing agents (present in the whitening agent) from reaching the underlying hard tissue. As a result, some whitening procedures call for pellicle damaging agents and procedures to be applied prior to the application of the whitening agent. Instead, the laser treatment removes the pellicle (and other biofilms if present) allowing the whitening agent to be applied directly to the dental hard tissue undergoing whitening (e.g., enamel, dentine, or cementum). In some cases, direct application of the whitening agent to the dental hard tissue allows the whitening agent to have a reduced dosage (e.g., reducing concentration or reduced quantity of whitening agent). In some embodiments, the whitening agent comprises one or more of hydrogen peroxide, carbamide peroxide, and sodium perborate.
In some embodiments, method 500 is repeated periodically. This is because, the laser treatment typically only affects an outer portion (e.g., thickness no more than about 500 μm, 100 μm, 50 μm, 10 μm, 5 μm, or 2 μm) of the treated surface. This outer portion possesses improved mechanical properties and results in a slowing of the processes associated with enamel aging. However, the outer treated portion is finite and will eventually succumb over time. Additionally, in some cases, a rewhitening will be performed repeatedly until a desired effect has been reached. For this reason, in some cases, it is necessary to repeat treatment periodically. In some cases, it is advantageous to repeat treatment at least once every 10, 5, 3, 2, 1, or 0.5 years. The literature, which describes the vast potential of laser treatment to prevent caries, fails to suggest that periodic retreatment may be necessary and instead tends to assume that a one-time treatment will suffice for most patients. Likewise, no known literature exists which describes the advantageous aspect of synergistic laser treatment and whitening. Additional disclosure related to laser treatment may be found in International Application No. PCT/US 21/15567, by C. Dresser et al., entitled “PREVENTATIVE DENTAL HARD TISSUE LASER TREATMENT SYSTEMS, METHODS, AND COMPUTER-READABLE MEDIA,” the entirety of which is incorporated herein by reference.
To aid in practice of the claimed invention and parameter selection a table is provided below with exemplary ranges and nominal values for relevant parameters.
It is to be noted that any one or more of the aspects and embodiments described herein may be conveniently implemented using one or more machines (e.g., one or more computing devices that are utilized as a user computing device for an electronic document, one or more server devices, such as a document server, etc.) programmed according to the teachings of the present specification, as will be apparent to those of ordinary skill in the computer art. Appropriate software coding can readily be prepared by skilled programmers based on the teachings of the present disclosure, as will be apparent to those of ordinary skill in the software art. Aspects and implementations discussed above employing software and/or software modules may also include appropriate hardware for assisting in the implementation of the machine executable instructions of the software and/or software module.
Such software may be a computer program product that employs a machine-readable storage medium. A machine-readable storage medium may be any medium that is capable of storing and/or encoding a sequence of instructions for execution by a machine (e.g., a computing device) and that causes the machine to perform any one of the methodologies and/or embodiments described herein. Examples of a machine-readable storage medium include, but are not limited to, a magnetic disk, an optical disc (e.g., CD, CD-R, DVD, DVD-R, etc.), a magneto-optical disk, a read-only memory “ROM” device, a random-access memory “RAM” device, a magnetic card, an optical card, a solid-state memory device, an EPROM, an EEPROM, and any combinations thereof. A machine-readable medium, as used herein, is intended to include a single medium as well as a collection of physically separate media, such as, for example, a collection of compact discs or one or more hard disk drives in combination with a computer memory. As used herein, a machine-readable storage medium does not include transitory forms of signal transmission.
Such software may also include information (e.g., data) carried as a data signal on a data carrier, such as a carrier wave. For example, machine-executable information may be included as a data-carrying signal embodied in a data carrier in which the signal encodes a sequence of instruction, or portion thereof, for execution by a machine (e.g., a computing device) and any related information (e.g., data structures and data) that causes the machine to perform any one of the methodologies and/or embodiments described herein.
Examples of a computing device include, but are not limited to, an electronic book reading device, a computer workstation, a terminal computer, a server computer, a handheld device (e.g., a tablet computer, a smartphone, etc.), a web appliance, a network router, a network switch, a network bridge, any machine capable of executing a sequence of instructions that specify an action to be taken by that machine, and any combinations thereof. In one example, a computing device may include and/or be included in a kiosk.
Computer system 500 includes a processor 504 and a memory 508 that communicate with each other, and with other components, via a bus 512. Bus 512 may include any of several types of bus structures including, but not limited to, a memory bus, a memory controller, a peripheral bus, a local bus, and any combinations thereof, using any of a variety of bus architectures.
Processor 504 may include any suitable processor, such as without limitation a processor incorporating logical circuitry for performing arithmetic and logical operations, such as an arithmetic and logic unit (ALU), which may be regulated with a state machine and directed by operational inputs from memory and/or sensors; processor 504 may be organized according to Von Neumann and/or Harvard architecture as a non-limiting example. Processor 504 may include, incorporate, and/or be incorporated in, without limitation, a microcontroller, microprocessor, digital signal processor (DSP), Field Programmable Gate Array (FPGA), Complex Programmable Logic Device (CPLD), Graphical Processing Unit (GPU), general purpose GPU, Tensor Processing Unit (TPU), analog or mixed signal processor, Trusted Platform Module (TPM), a floating-point unit (FPU), and/or system on a chip (SoC).
Memory 508 may include various components (e.g., machine-readable media) including, but not limited to, a random-access memory component, a read only component, and any combinations thereof. In one example, a basic input/output system 516 (BIOS), including basic routines that help to transfer information between elements within computer system 500, such as during start-up, may be stored in memory 508. Memory 508 may also include (e.g., stored on one or more machine-readable media) instructions (e.g., software) 520 embodying any one or more of the aspects and/or methodologies of the present disclosure. In another example, memory 508 may further include any number of program modules including, but not limited to, an operating system, one or more application programs, other program modules, program data, and any combinations thereof.
Computer system 500 may also include a storage device 524. Examples of a storage device (e.g., storage device 524) include, but are not limited to, a hard disk drive, a magnetic disk drive, an optical disc drive in combination with an optical medium, a solid-state memory device, and any combinations thereof. Storage device 524 may be connected to bus 512 by an appropriate interface (not shown). Example interfaces include, but are not limited to, SCSI, advanced technology attachment (ATA), serial ATA, universal serial bus (USB), IEEE 1394 (FIREWIRE), and any combinations thereof. In one example, storage device 524 (or one or more components thereof) may be removably interfaced with computer system 500 (e.g., via an external port connector (not shown)). Particularly, storage device 524 and an associated machine-readable medium 528 may provide nonvolatile and/or volatile storage of machine-readable instructions, data structures, program modules, and/or other data for computer system 500. In one example, software 520 may reside, completely or partially, within machine-readable medium 528. In another example, software 520 may reside, completely or partially, within processor 504.
Computer system 500 may also include an input device 532. In one example, a user of computer system 500 may enter commands and/or other information into computer system 500 via input device 532. Examples of an input device 532 include, but are not limited to, an alpha-numeric input device (e.g., a keyboard), a pointing device, a joystick, a gamepad, an audio input device (e.g., a microphone, a voice response system, etc.), a cursor control device (e.g., a mouse), a touchpad, an optical scanner, a video capture device (e.g., a still camera, a video camera), a touchscreen, and any combinations thereof. Input device 532 may be interfaced to bus 512 via any of a variety of interfaces (not shown) including, but not limited to, a serial interface, a parallel interface, a game port, a USB interface, a FIREWIRE interface, a direct interface to bus 512, and any combinations thereof. Input device 532 may include a touch screen interface that may be a part of or separate from display 536, discussed further below. Input device 532 may be utilized as a user selection device for selecting one or more graphical representations in a graphical interface as described above.
A user may also input commands and/or other information to computer system 500 via storage device 524 (e.g., a removable disk drive, a flash drive, etc.) and/or network interface device 540. A network interface device, such as network interface device 540, may be utilized for connecting computer system 500 to one or more of a variety of networks, such as network 544, and one or more remote devices 548 connected thereto. Examples of a network interface device include, but are not limited to, a network interface card (e.g., a mobile network interface card, a LAN card), a modem, and any combination thereof. Examples of a network include, but are not limited to, a wide area network (e.g., the Internet, an enterprise network), a local area network (e.g., a network associated with an office, a building, a campus or other relatively small geographic space), a telephone network, a data network associated with a telephone/voice provider (e.g., a mobile communications provider data and/or voice network), a direct connection between two computing devices, and any combinations thereof. A network, such as network 544, may employ a wired and/or a wireless mode of communication. In general, any network topology may be used. Information (e.g., data, software 520, etc.) may be communicated to and/or from computer system 500 via network interface device 540.
Computer system 500 may further include a video display adapter 552 for communicating a displayable image to a display device, such as display device 536. Examples of a display device include, but are not limited to, a liquid crystal display (LCD), a cathode ray tube (CRT), a plasma display, a light emitting diode (LED) display, and any combinations thereof. Display adapter 552 and display device 536 may be utilized in combination with processor 504 to provide graphical representations of aspects of the present disclosure. In addition to a display device, computer system 500 may include one or more other peripheral output devices including, but not limited to, an audio speaker, a printer, and any combinations thereof. Such peripheral output devices may be connected to bus 512 via a peripheral interface 556. Examples of a peripheral interface include, but are not limited to, a serial port, a USB connection, a FIREWIRE connection, a parallel connection, and any combinations thereof.
The foregoing has been a detailed description of illustrative embodiments of the invention. Various modifications and additions can be made without departing from the spirit and scope of this invention. Features of each of the various embodiments described above may be combined with features of other described embodiments as appropriate in order to provide a multiplicity of feature combinations in associated new embodiments. Furthermore, while the foregoing describes a number of separate embodiments, what has been described herein is merely illustrative of the application of the principles of the present invention. Additionally, although particular methods herein may be illustrated and/or described as being performed in a specific order, the ordering is highly variable within ordinary skill to achieve methods, systems, and software according to the present disclosure. Accordingly, this description is meant to be taken only by way of example, and not to otherwise limit the scope of this invention.
Exemplary embodiments have been disclosed above and illustrated in the accompanying drawings. It will be understood by those skilled in the art that various changes, omissions and additions may be made to that which is specifically disclosed herein without departing from the spirit and scope of the present invention.
The methods, systems, and devices discussed above are examples. Various configurations may omit, substitute, or add various procedures or components as appropriate. For instance, in alternative configurations, the methods may be performed in an order different from that described, and that various steps may be added, omitted, or combined. For example, in some embodiments, fluoride treatment is omitted after laser treatment. Also, features described with respect to certain configurations may be combined in various other configurations. Different aspects and elements of the configurations may be combined in a similar manner. Technology evolves and, thus, many of the elements are examples and do not limit the scope of the disclosure or claims.
Embodiments of the present disclosure, for example, are described above with reference to block diagrams and/or operational illustrations of methods, systems, and computer program products according to embodiments of the present disclosure. The functions/acts noted in the blocks may occur out of the order as shown in any flowchart. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Additionally, or alternatively, not all of the blocks shown in any flowchart need to be performed and/or executed. For example, if a given flowchart has five blocks containing functions/acts, it may be the case that only three of the five blocks are performed and/or executed. In this example, any of the three of the five blocks may be performed and/or executed.
A statement that a value exceeds (or is more than) a first threshold value is equivalent to a statement that the value meets or exceeds a second threshold value that is slightly greater than the first threshold value, e.g., the second threshold value being one value higher than the first threshold value in the resolution of a relevant system. A statement that a value is less than (or is within) a first threshold value is equivalent to a statement that the value is less than or equal to a second threshold value that is slightly lower than the first threshold value, e.g., the second threshold value being one value lower than the first threshold value in the resolution of the relevant system.
Specific details are given in the description to provide a thorough understanding of example configurations (including implementations). However, configurations may be practiced without these specific details. For example, well-known circuits, processes, algorithms, structures, and techniques have been shown without unnecessary detail in order to avoid obscuring the configurations. This description provides example configurations only, and does not limit the scope, applicability, or configurations of the claims. Rather, the preceding description of the configurations will provide those skilled in the art with an enabling description for implementing described techniques. Various changes may be made in the function and arrangement of elements without departing from the spirit or scope of the disclosure.
Having described several example configurations, various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the disclosure. For example, the above elements may be components of a larger system, wherein other rules may take precedence over or otherwise modify the application of various implementations or techniques of the present disclosure. Also, a number of steps may be undertaken before, during, or after the above elements are considered.
Having been provided with the description and illustration of the present application, one skilled in the art may envision variations, modifications, and alternate embodiments falling within the general inventive concept discussed in this application that do not depart from the scope of the following claims.
This application claims the benefit of priority from Provisional Pat. App. No. 63/226,706, entitled “SYNERGISTIC LASER CLEANING AND WHITENING OF TEETH,” filed on Jul. 28, 2021, and incorporated by reference in its entirety within.
| Number | Date | Country | |
|---|---|---|---|
| 63226706 | Jul 2021 | US |
