Patent Application
20210370052
This application is directed to an improved dental implant and related method for treating infected dental implants. More specifically and according to the present invention, treatment can be performed, but without having to first remove the crown portion of the dental implant.
Surgical medical implants are used in patients with many different injuries or medical problems. For example, metal implants may be used for any individual that needs to replace a tooth in a dental procedure.
More specifically and when a patient has a tooth that needs to be removed, the standard procedure is to replace that tooth with a prosthetic by means of a tooth-root replacement. This replacement typically is composed of three (3) main components including a post, an abutment, and a ceramic prosthetic tooth referred to as the crown. The tooth and roots are extracted from the jaw bone of the patient and the bone is reamed to properly fit the post, which is typically metallic. The dental implant is surgically placed in the jaw bone to which it fuses in a process referred to as “osseo-integration”. A healing abutment is placed until the site is sufficiently healed. The healing abutment is then removed, and another metal abutment is screwed onto the post. The prosthetic crown can then be adjoined to the metal abutment. The crown typically is made from a non-conductive material having a hollowed core that allows the abutment to be press fit inside. It is also common to have an abutment that screws into the crown itself. The screw hole is typically at the top of the tooth and then is filled once the complete implant is in place. When completed, the only visible portion in the mouth is the crown.
One potential problem with any surgical metal implant is that they tend to allow for the growth of bacteria on the surface. This may increase the patient's risk for an infection. This issue is especially prevalent in the mouth due to a large bacterial presence. It has been estimated that roughly 20 percent of all subjects receiving a dental implant can develop infections. As bacteria colonize upon foreign surfaces such as metal, they form biofilms. Biofilms are protective extracellular matrix materials that encapsulate bacterial colonies onto a surface and protect them. Biofilms can be 500-5000 times more resistant to antibiotics than common planktonic bacteria because the antibiotics cannot penetrate the biofilm. A significant percentage of dental implants acquire periimplantitis, or biofilm infection of the implant that can cause complications which include implant loosening, gum and bone loss. To decrease the risk of infection, electrodes can provide electrical stimulation to disrupt the growth of bacteria. It has been shown in scientific literature that the application of cathodic current to metal samples create chemical reactions at that surface that can disrupt and kill bacterial biofilms formed on the surface of the metal implant.
Electrical connection to the dental implant to conduct a treatment can be difficult due to the non-conductive crown that sits on top of the metal post and abutment, with the crown being located above the gum line. Alternative and less desirable approaches to electrically connect to the metallic post include removing the crown or using a needle to pierce through the gum. Each alternative has several issues that make it largely impractical. Accordingly, there is a need in the field to enable a biofilm treatment procedure to be conducted upon an infected metal dental implant, but without having to first remove the crown in advance of treatment.
The present invention relates to the use of voltage-controlled electrical treatment to the surfaces of a metal implant, such as a dental implant, as a method to prevent and eradicate microbial colonization on the surface, such as periimplantitis. This invention is implemented by application of a DC electrical current to a metallic implant. The system requires at least two electrodes, but can also utilize three or more electrodes. Specifically and in the case of three electrodes, the system includes a counter electrode, a working electrode, and a reference electrode. The counter electrode delivers the current to the working electrode to maintain a steady DC potential with respect to the stable reference electrode. In the case of a dental implant, the metallic surface of the implant post and abutment act as the working electrode. The system uses the electrochemical properties of the at least two electrodes in a direct current (DC) circuit to disrupt and chemically kill the biofilm, which means the electrodes must be submerged or contacting an electrolyte that transports the electrical energy through chemical reactions to the other electrode(s). Human bone and soft tissue provide this electrolyte media for conduction, and thus the complete surface area of the dental implant embedded in the bone receives treatment. Full surface treatment optimizes effectiveness against biofilm infections.
The present disclosure provides a means for making an electrical connection to a metallic post and abutment of a specialized dental implant. The crown-abutment assembly of the implant improves the ease and efficiency of treatment using cathodic voltages. When applying therapy to an infected dental implant, it is preferable to keep the crown attached as opposed to alternative attachment mechanisms that require direct attachment to the abutment and removal of the crown. The herein described implant contains an easily accessible conductive contact point that provides full electrical conduction to the remainder of the implant while the crown remains attached.
Therefore and in accordance with at least one aspect, a novel apparatus is described that enables reliable electrical connection to the metal abutment and post of a dental implant in order for the chemical reaction to proceed safely and effectively. According to one version, a metal core is incorporated within the crown and coupled to the abutment, wherein the core is configured to create an exposed metal contact point or area on the surface of the crown that provides a simple but effective way to electrically connect to the metal post and abutment of the dental implant. Treatment of the dental implant is enabled, but without resorting to removal of the crown in order to perform the treatment.
In one version, the crown includes the metallic core in which a portion of the core extends transversely relative to a center axis of the post to a side wall of the crown. The transverse portion extends through an opening formed in the crown as the exposed metallic area, which is configured for receiving a needle or other electrically conductive member coupled to a potentiostat or other similar device capable of delivering an electrical potential. Aesthetically, the exposed metallic area can be provided on an inner side wall of the crown. Alternatively, the exposed area of the metallic core can extend upwardly through a top surface of the dental crown.
According to another version, the hollow crown can be matched to the abutment of the dental implant using a key-shaped or similar form of configuration. More specifically, a key-shaped extension of the abutment is shaped and configured for disposition within a recess formed in a side wall of the dental crown, thereby providing an exposed and accessible metallic area. It will be understood that other suitable versions and configurations can be made in accordance with various aspects of the invention.
According to another aspect of the present invention, a method is provided for enabling treatment of a dental implant in order to disrupt bacterial deposits using cathodic voltages, the dental implant comprising a metallic post secured to the jaw bone of a subject and a prosthetic tooth or crown, made from a non-conductive material attached onto a metal abutment of the metallic post, the method comprising:
An advantage is that the herein described implant and related method are very minimally invasive for purposes of treating infections. Accordingly, the herein described techniques are less time consuming, while yet still being reliable.
In addition and as described herein, the dental implant can be used in conjunction with various treatment systems used for disrupting biofilms, the systems including 2, 3, 4 or more electrodes and with the dental implant being used as a working electrode without removal of the crown.
These and other features and advantages will be readily apparent from the following Detailed Description, which should be read in conjunction with the accompanying drawings.
The following relates to certain exemplary embodiments of a dental implant configured for electrical treatment in the case of infection using cathodic voltages as well as treatment systems used with the implant. It will be understood that various modifications are possible. In addition, various terms are used throughout the following discussion in order to provide a suitable frame of reference for the accompanying drawings. These terms, which may include “first”, “second”, “third”, “upper”, “lower”, “internal”, “external”, “inner”, “outer” and the like, are not intended to be overly limiting of the present invention, except where so specifically indicated.
The accompanying drawings are described throughout in order to convey salient features of the present invention, but the drawings should not be relied upon for scaling or similar purposes.
The herein described system and method relies upon the introduction of an electrical current to an electrochemical cell. As a matter of background and for electrochemical(redox) processes to occur, there must be an anode and a cathode within an electrolyte solution. The anode is a metallic surface where oxidative reactions occur, and the cathode is another metallic surface where reduction reactions occur. A reduction reaction occurs when the material of interest gains electrons and thereby decreases the oxidation state of the molecules. The electrolyte that the electrodes each reside in provides the electrical connection by facilitating the flow of electrons shuttled by ion carriers, such as electrolytic sodium or potassium ions. Electrons are driven from the anode to the cathode through the electrical path via a potentiostat or similar device. More specifically, a potentiostat is an instrument used to drive current from a counter electrode to a working electrode in order to keep the voltage on the working electrode at a constant value compared to a stable reference electrode. One such procedure used for the treatment of biofilms on a metallic implant is described in U.S. Pat. No. 9,616,142, the entire contents of which are herein incorporated by reference.
According to this treatment procedure, the anode represents the counter electrode and the cathode represents the working electrode. Using a potentiostat, a user can dictate which electrochemical process is occurring on the working electrode and at what rate the process occurs simply by adjusting the applied voltage parameters with respect to a separate reference electrode. The cathodic reactions occurring at the working electrode produce hydroxide ions, resulting in an alkaline pH at on the implant surface, while also producing different reactive oxidative chemical species that are bactericidal for existing biofilms.
In a clinical setting, the above-noted technique has been shown as a way to fight bacterial biofilm infections on metallic implants in the most minimally invasive way possible. In this setting, the patient's body can act as an electrochemical cell by using the metal implant as the cathode and the counter electrode as the anode. It has been shown that the above techniques can be used for the treatment of various orthopedic implants as well as dental implants. As noted above, an issue is the dental crown, the latter being made from a non-conductive material covering the surgically implanted metallic post.
Removing the dental crown is an option that many dentists prefer not to perform because the crown may break or cause extra trauma to the afflicted tissue. In the case where a biofilm exists on the post and abutment, the flow of electrons into the bulk metal, out the metal surface, and into the electrolytic environment, will create bactericidal chemical species that attack the biofilm from the metal surface outwards. pH is also a large factor in the bactericidal effect as laboratory testing has shown that microenvironment pH levels microns away from the surface can become alkaline, as high as a pH of 12, within minutes of electrical stimulation.
In brief and according to this application, a dental crown is provided that increases the efficiency of the above-noted form of treatment as it pertains to a dental implant. The improved and novel dental crown allows the dentist to access the fully bone-embedded implant surface for use as the working electrode for electrical stimulation, while still maintaining patient safety parameters and a minimally invasive profile.
The following embodiments are exemplary design versions of a dental crown that has been configured with an exposed metal contact surface on the side or other surface of the crown that is electrically continuous through the abutment and to the embedded post of a dental implant.
Referring to
More specifically and according to this specific embodiment, the metallic core 230 extends upwardly as shown more specifically in
The overall shape and configuration of the metallic core 230 can be suitably varied provided that the dental crown 220 can adequately and structurally function primarily as a prosthetic tooth. For example and in lieu of extending transversely as shown, the proximal end of the metallic core 230 can extend vertically through the hollow cavity 224 until exposed at a top surface of the crown 220.
In this embodiment and unlike the version shown in
Like the previous embodiment, this implant design introduces an exposed metal surface or zone 334 on the side of the dental crown 320 that allows direct electrical connection to the abutment 308 and post 210,
In each of the herein described embodiments, the exposed metallic contact zone 234, 334 is introduced on a surface of the crown 220, 320 that provides the dentist access in order to apply a cathodic voltage as part of a treatment that can effectively disrupt and eliminate biofilm from a dental implant, but without first removing the crown 220, 320.
As shown in
Each cathodic voltage treatment system 400, 500 and 600, shown diagrammatically in
Each of the above systems/configurations permit reliable treatment of the dental implant, but without requiring removal of the crown. The exposed metallic surface area of the crown permits electrical conduction to the remainder of the dental implant. Exposed metal surfaces are both safe and cosmetically acceptable when applying these designs and embodiments. A distinct differentiator from alternative dental treatment techniques is that the herein described implant promotes conduction over the entire bone-embedded surface of the dental implant, and not just conduction, for example, within the abscess pocket. This differentiator is a significant advance, especially in regard to dental implant posts. Implant posts are typically manufactured with a very rough, coarse microsurface to promote osseointegration. One issue this microsurface can create is that bacteria are able to “hide” within the crevices of the microstructure, even when bone matrix are apparently grown into the surface. The approach and design of herein described apparatus allows for thorough treatment of all microstructures in the metal, even with bone present, to eliminate all bacteria from those locations. It has been found and substantiated in scientific literature that at optimized treatment parameters, matrix embedded bone cells that are local to the reaction are not affected to a high degree.
Other alternative techniques for treatment of conventional dental implants are available but each of the techniques are believed to be inferior to the implants described according to the present invention. A pair of these alternatives are briefly described as follows, each alternative including two electrodes that can be used to deliver a cathodic voltage treatment in which the metal implanted post and abutment represent the working electrode along with a counter electrode.
In the first alternative, a needle is used to pierce through the gum to make physical contact with the post, creating a working electrode connection. A small tube is the inserted into the abscess of the infection to pump electrolyte into the abscess. The electrolyte from the tube acts as a conductive bridge to an external electrode provided in the tube or at the other terminal of the tube. The disadvantages of this setup include executing a secure attachment to a small embedded implant with a needle, and the effectiveness of the treatment based on the electrode set up. Needle placement in this fashion will be difficult and could easily disconnect during treatment. Also, with the electrolyte from the tube acting as the main transport path, the treatment will be locally concentrated only in the open abscess and not on the whole bone to metal interface where additional biofilm may exist.
The second alternative treatment technique requires removal of the dental crown to electrically connect the electrodes to the infected metal post. Once the crown is removed, a small electrolyte-filled chamber is attached to the implant that flows electrolyte downward onto the implant and abscess. The counter electrode exists inside the chamber and therefore the formed conductive path is from the dental implant back up the electrolyte and into the chamber. Each of the above-noted alternatives commonly require an added electrolyte to connect to the external counter electrode. The disclosed invention demonstrates advantages over these alternatives due to a minimally invasive and secure profile that doesn't require removal of the crown. The disclosed invention also improves the efficacy of the therapy by using the local bone and body tissue as the conductive path for a more evenly distributed and thorough treatment.
It will be understood that modifications and variations of the described embodiments are possible and within the intended scope of the invention and in accordance with the following claims.
