Methods of Manufacture thereof

Cross-Reference to Related Application

The present application claims priority to and the benefit of US patent application serial No. 62/545,113, filed August 14, 2017, which is hereby expressly incorporated by reference in its entirety.

Technical Field

The present invention relates to the field of dentistry and more particularly, relates to customized dental implants that are formed of a biomimetic composite material that is for the application of immediate tooth replacement and includes processed dentin from an extracted tooth and a bioactive cement. Background

Titanium screw type dental implants are the current standard for replacing failing or missing natural teeth that require replacement due to tooth decay, periodontal disease, or trauma. The dental implant effectively replaces the function of the natural root by connecting to both the jawbone and the crown. The typical process for placing standard dental implants involves a process where a hole is drilled into the bone and the implant device, typically made of titanium alloy (or other metal or ceramic material), is inserted (or threaded) into the cavity and allowed to fuse with the bone by a process known as osseointegration. While dental implants are the current state of the art for tooth replacement, they involve an invasive surgical procedure and significant risks. Aside from intraoperative surgical risks, a high incidence of titanium implant failures has been reported after placement due to a variety of reasons. These failures can be due to prosthetic material failure, improper surgical placement resulting in damage to adjacent teeth or vital anatomical structures, poor esthetics, infection, and a disease affecting the supporting bone to implant interface known as peri-implantitis.

Often times when an implant fails, the amount of bone already lost or that needs to be removed in order to retrieve the titanium implant can be catastrophic and this makes replacing that implant extremely difficult, if not impossible in some cases. This leaves many patients debilitated and often times requires more extensive surgeries to compensate for the damage. The need for improvement in this field is well known among any clinicians and patients that have ever experienced an implant failure or have experienced the time and cost of these procedures.

Summary

In accordance with one embodiment, the present invention is directed to a method and composite material for the application of immediate tooth replacement. The method generally involves the step of removing the patient's failing tooth and as opposed to discarding it, the dentin (the layer which makes up the majority of our teeth) is processed into a particle form that forms part of the composite material that is reconstructed into a tooth form implant that mimics the shape and composition of the original tooth. While the present invention is described throughout in terms of removing a tooth from a patient (autograft) and then using the extracted tooth for processing and forming the composite material, it will be appreciated and understood that the tooth does not necessarily have to come from the patient that requires tooth replacement. For example, the extracted tooth can be from another person or a cadaver (allograft) or an animal (xenograft) and after processing of the dentin from the extracted tooth, the tooth form implant that is made from the processed dentin is then implanted into a different person.

In one embodiment, the dental implant comprises a body formed of a biomimetic composite material that includes processed dentin from an extracted tooth and a bioactive cement. More particularly, the biomimetic composite material can be formed, at least in part, of a suitable dental cement material that yields a composite material which is much closer in composition, color, and mechanical properties to natural teeth. One class of dental cements that are suitable for use in the present invention are commercially available calcium silicate based dental cement materials (a bioactive cement). This bioactive cement mimics the mechanical properties of natural teeth in terms of material strength, high biocompatibility, and can be used as a dentin substitute due to its favorable long-term mechanical and antibacterial properties. Moreover, this bioactive cement demonstrates a high macro and micromechanical bond strength when incorporated with the processed dentin particles resulting in the composite material retaining impressive mechanical strengths far exceeding masticatory forces. Within the same class of calcium silicate-based cements is a dental cement material that is derived from ordinary Portland cement. This material is known as mineral trioxide aggregate (MTA). MTA is commercially available in various forms and compositions. Outside of calcium silicate materials is another class of materials known as glass ionomer and resin modified glass ionomer cements which can be used to form the composite material. These are fluoroaluminosilicate based materials that are also

commercially available and used as restorative materials in dentistry. These glass ionomer cements are commonly used in the dental practice.

As described herein, there are a number of different fabrication methods for forming the tooth form implant, including 3D printed or elastomeric impression molds for casting, or custom milling of block material to fabricate the 3D implants. The present composite material offers at least several benefits over traditional implants including more rapid and predictable healing that is consistent with the practice of tooth replantation. The present dentin/cement composite implants also have the added benefit over traditional implants by reducing severe bone loss and compromise of supporting periodontal structures if they fail. Thus, the present invention addresses the need for customized implants made of safer and durable materials that eliminate or delay the need for traditional implant surgery until later in life.

Brief Description of the Drawing Figures

Fig. 1 is a cross-sectional view of a first tooth form implant in the form of an incisor/canine implant;

Fig. 2 is a cross-sectional view of a second tooth form implant in the form of a premolar;

Fig. 3 is a cross-sectional view of a third tooth form implant in the form of a molar; Fig. 4 is a view of exemplary molds created by an additive manufacturing technique (e.g., 3D printing);

Fig. 5 is a perspective view of a pair of interlocking syringes that can be used for mixing the composite materials;

Figs. 6A-6C illustrate the steps for forming composite blocks that are subjected to a milling operation to form the customized tooth form implant;

Fig. 7 is a view of exemplary silicone impression molds;

Figs. 8A-8D illustrate different tooth form implants made in accordance with the present invention;

Fig. 9 is a flowchart setting forth the steps of an exemplary 3D printing process used to form a customized tooth form implant;

Fig. 10 is a flowchart setting forth the steps of an exemplary custom milling process used to form a customized tooth form implant;

Fig. 11 is a flowchart setting forth the steps of an exemplary elastomeric casting process used to form a customized tooth form implant; and Fig. 12 is a cross-sectional view of another tooth form implant that is formed of an outer hollow shell formed from a patient's extracted tooth.

Detailed Description of Certain Embodiments

As used herein, the term "proximal" shall mean close to the operator (less into the body) and "distal" shall mean away from the operator (further into the body). In positioning a medical device inside a patient, "distal" refers to the direction away from an insertion location and "proximal" refers to the direction close to the insertion location.

Unless otherwise specified, all numbers expressing quantities, measurements, and other properties or parameters used in the specification and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless otherwise indicated, it should be understood that the numerical parameters set forth in the following specification and attached claims are approximations. At the very least and not as an attempt to limit the application of the doctrine of equivalents to the scope of the attached claims, numerical parameters should be read in light of the number of reported significant digits and the application of ordinary rounding techniques.

The apparatuses and methods are not limited in any way to the illustrated embodiments and/or arrangements as the illustrated embodiments and/or arrangements described below are merely exemplary of the present apparatuses and methods, which can be embodied in various forms as appreciated by one skilled in the art. Therefore, it is to be understood that any structural and functional details disclosed herein are not to be interpreted as limiting the present application, but rather are provided as a representative embodiment and/or arrangement for teaching one skilled in the art one or more ways to implement the present apparatuses and/or methods. Moreover, just because a certain feature is depicted in combination with a particular set of other features, no intent to so limit the invention can be inferred and each feature can be combined with any other set of other features.

Figs. 1-3 and 8A-8D illustrate a number of different customized tooth form implants that are made in accordance with the present invention. As one of skill in the art readily understands a tooth is divided into two basic parts; namely, the crown, which is the visible, white part of the tooth, and the root, which you can't see. The root extends below the gum line and anchors the tooth into the bone. A person ^' s teeth contain four kinds of tissue and each performs a different function. The four kinds of tissue include:

• Enamel. Enamel is the visible substance chat covers the tooth crown. Harder than bone, enamel protects the tooth from decay. Enamel is made up of phosphorous and calcium, in a bydrox apatite form, which is more mineralized than dentin and hone. The high hydroxyapatite content in enamel and natural teeth explain their strength and resistance to wear or breakdown.

Dentin. Dentin is the underlying layer just beneath the enamel, which is calcified and is also composed of calcium and phosphate. Dentin is not quite as hard as enamel, but harder than the surrounding bone. It makes up the majority of the crown and roots of teeth and is very similar in chemical composition to bone, except that it has a slightly higher mineral content. Dentin like enamel is composed of an organic (mostly collagen) matrix and an inorganic hydroxyapatite (calcium and phosphorous) component.

Cementum This tissue covers the root dentin on one side and the periodontal ligament which is attached to the surrounding alveolar bone on the other. Two types of cementum are present, cellular and acellular. Often times, cementum can be lost from the tooth in areas with disease or after mechanical debridement (by aggressive tooth brushing or from instro mentation at the dental office). Cementum does have the capacity at times to reform around the tooth after it has been lost assuming there is ample blood supply and cernentoblasts (the cementum producing cells) are still present within the periodontal ligament space. The cementum, periodontal ligament, and alveolar bone make up what is known as the Periodontium, which is what keeps teeth retained in the jawbone. This is something that is only present around natural teeth. Contrary to the direct fusion of traditional screw type implants to the alveolar bone, also known as the process of osseointegration

Pulp. Pulp is found at the center of your tooth and contains the blood vessels, nerves, and other soft tissues that deliver nutrients and signals to your teeth.

Each type of tooth has a slightly different shape and performs a different job. The attached figures illustrate the general shapes of the different types of teeth; however, it will be readily understood that the actual shape of a tooth is patient specific. The types of teeth include:

incisors, incisors are the eight teeth in the front and center of the mouth (four on top and four on bottom) and they are designed to tear food apart in order to be chewed by the back teeth.

Canines. The four canines are the sharpest teeth and are also used for ripping and tearing food apart.

Premolars. Premolars, or bicuspids, are used for chewing and grinding food. There are four premolars on each side of your mouth, two on the upper and two on the lower jaw. • Molars. Molars are also used for chewing and grinding food. They are the teeth found furthest back on both sides. They often have multiple roots and are designed to withstand the highest chewing forces in the oral cavity.

The tooth form implant that is required is thus dictated by the type of tooth that is to be replaced and therefore, the tooth form implant will take the form of one of the above mentioned four types of teeth.

Figs. 1-3 and 8A-8D illustrate a number of different customized tooth form implants having different shapes and sizes. More particularly, Fig. 1 illustrates a first tooth form implant 100 in the form of an incisor/canine tooth implant. The first tooth form implant 100 has a first portion 102 at a first end 104 and a second portion 106 at an opposing second end 108. The first portion 102 resembles the root portion of the tooth, while the second portion 106 resembles the crown portion of the tooth. As described herein, the first tooth form implant 100 is constructed in view of the anatomy of the patient and in particular, the size and shape of the first tooth form implant 100 is intended to mimic the tooth that had been extracted or is otherwise missing. In one exemplary embodiment, the height (length) of the first portion 102 is between about 12 mm to about 18 mm and the height (length) of the second portion 106 is between about 3 mm and about 8 mm. The width (apex to cervix) can be between about 1 mm to about 9 mm.

In accordance with one embodiment of the present invention, the first tooth form implant 100 is defined by a core 110 and an outer layer 120 that surrounds the core 110. The outer layer 120 can at least substantially cover the entire outer surface of the core 110. The core 110 is formed of a first material, while the outer layer 120 is formed of a second material that is different than the first material.

The thickness of the core 110 is typically greater than the thickness of the outer layer 120. For example, the thickness of the core 110 can be between about 1 mm to about 10 mm, while the thickness of the outer layer 120 can be between about 500 μπι and about 1500 μπι.

More specifically, the core 110 can be formed of a biocompatible, bioactive cement that is suitable for the intended application described herein. The core 110 can be formed 100% of the biocompatible, bioactive cement.

In one preferred embodiment, the bioactive cement comprises Biodentine® material which is commercially available from Septodont and is a calcium silicate-based cement. As previously mentioned, the mechanical properties of the Biodentine® material have been tailored to mimic natural human dentin and the product is marketed as a "Dentin

Replacement Material" due to its nearly identical physicochemical properties. In addition, long-term clinical studies have confirmed the effectiveness of this material in its ability to withstand the multi-axial and variable forces generated in the oral cavity. These long-term studies have demonstrated the great durability of the material and excellent bioactivity that it maintains at the dentin, cementum, periodontal ligament and bone interfaces.

The outer layer 120 is formed of a biomimetic composite material that is made in accordance with the present invention. The biomimetic composite material is made of a calcium silicate-based cement material (e.g., Biodentine® material) and processed dentin material from an extracted tooth (from either the same patient, another human, or animal donor/cadaver). The combination of these materials yields a composite material which is much closer (compared to other materials) in composition, color, and mechanical properties to natural teeth. This bioactive cement mimics the mechanical properties of natural teeth in terms of material strength, high biocompatibility, and can be used as a dentin substitute due to its favorable long-term mechanical and antibacterial properties. Moreover, the bioactive cement demonstrates a high macro and micromechanical bond strength when incorporated with the processed dentin material (e.g., dentin particles) resulting in the composite material retaining impressive mechanical strengths far exceeding masticatory forces.

Testing of the implant 100 has revealed compressive strengths and micro-mechanical bonding of the bioactive cement to the particulate dentin at dentin concentrations that far exceed what would be needed for use as an implant.

Applicant has uncovered that the composite materials perform very similarly to natural teeth when being prepared with any conventional dental rotary instruments. The composite material is able to be machined and sectioned using diamond or carbide lathes, burs, and discs without unwanted discrimination or separation of the two components. This good bonding of the dentin particles to the cement material is due to the flow of the cement material into the dentinal tubules, which has been confirmed in cross sections analyzed by SEM. The dentinal tubules typically have a diameter between 1-3 microns in size. On each dentin particle, there would be a minimum of several hundred exposed tubules. This creates a durable interlocking composite network without the need for any adhesives.

The mechanical properties of these composite implants are intended to be closer to the range of human dentin and bone. The mismatch of material mechanical properties between traditional metal/zirconia screw type implants and surrounding bone has been extensively documented in dental and orthopedic literature. The change in stress distribution from dynamic forces at the bone to implant interface, also known as stress shielding is a significant issue that may contribute to the high rates of implant failures. This is an important factor that was kept in mind for the design of the composite implants in accordance with the present invention. By matching the composite material properties more closely to native tissues, a more natural distribution of multi-axial stresses results.

The relative amounts of the dentin and bioactive cement within the biomimetic composite material can vary depending upon the particular application and based on other considerations. For example, the dentin can comprise from about 10 percent to about 50 percent by weight of the total biomimetic composite material. In one embodiment, the ratio of dentin to the bioactive cement is about 1 :1. However, it will be appreciated that the percentage of dentin can be greater than 50%.

In an alternative embodiment, the first tooth form implant 100 is only made up of core

110. In other words, the first tooth form implant 100 is made entirely from the bioactive cement (100% bioactive cement).

Fig. 2 illustrates a second tooth form implant 200 in the form of a premolar tooth implant. The second tooth form implant 200 has a first portion 202 at a first end 204 and a second portion 206 at an opposing second end 208. The first portion 202 resembles the root portion of the tooth, while the second portion 206 resembles the crown portion of the tooth. As described herein, the second tooth form implant 200 is constructed in view of the anatomy of the patient and in particular, the size and shape of the second tooth form implant 200 is intended to mimic the tooth that had been extracted or is otherwise missing. In one exemplary embodiment, the height (length) of the first portion 202 is between about 12 mm to about 18 mm and the height (length) of the second portion 206 is between about 3 mm and about 8 mm. The width (apex to cervix) can be between about 1 mm to about 9 mm.

In accordance with one embodiment of the present invention, the second tooth form implant 200 is defined by a core 210 and an outer layer 220 that surrounds the core 210. The outer layer 220 can at least substantially cover the entire outer surface of the core 210. The core 210 is formed of a first material, while the outer layer 220 is formed of a second material that is different than the first material. More specifically, the core 210 can be formed of a biocompatible, bioactive cement that is suitable for the intended application described herein. The core 210 can be formed 100% of the biocompatible, bioactive cement.

The thickness of the core 210 is typically greater than the thickness of the outer layer

220. For example, the thickness of the core 210 can be between about 1 mm to about 10 mm, while the thickness of the outer layer 220 can be between about 500 μπι and about 1500 μπι. The core 210 can be formed of a biocompatible, bioactive cement that is suitable for the intended application described herein. The core 210 can be formed 100% of the biocompatible, bioactive cement, preferably, Biodentine® material as described above.

The outer layer 220 is formed of the biomimetic composite material described above. More specifically, the biomimetic composite material is made of a calcium silicate-based cement material (e.g., Biodentine® material) and processed dentin material from an extracted tooth (from either the patient, a donor/cadaver, or an animal source). It will be appreciated that the dentin can be derived from a number of different sources including but not limited to primary (baby teeth) or permanent (wisdom teeth/premolars extracted for orthodontic purposes).

Once processed, the dentin particles taken from extracted teeth can be stored under dry conditions for future use for the same patient. The dentin particulate can be stored in the office or in an offsite facility. More specifically, the dentin can thus be stored (tooth banking) in: 1) either vacuum-sealed dry conditions or designated freezer for short-term to long term storage in the dental office; 2) stored or cryopreserved in an offsite facility such as view of long-term storage protocols (Schwartz 1986, IJOMS) which can be modified to replace human serum and tissue culture media with PBS (phosphate buffered saline) or distilled water; and/or 3) storage chambers can be specifically designed to house teeth in a manner that reduces microbial contamination or degradation of the material and allows for safe and stable transport and long term storage of extracted tooth material.

As mentioned, it is also possible that allograft dentin particles (from other donors) can be used for this purpose assuming they are screened for communicable diseases and unable to induce any unwanted immune reactions.

The relative amounts of the dentin and bioactive cement within the biomimetic composite material can vary depending upon the particular application and based on other considerations. For example, the dentin can comprise from about 10 percent to about 50 percent by weight of the total biomimetic composite material. In one embodiment, the ratio of dentin to the bioactive cement is about 1 :1. However, it will be appreciated that the percentage of dentin can be greater than 50%.

In an alternative embodiment, the second tooth form implant 200 is only made up of the core 210. In other words, the second tooth form implant 200 is made entirely from the bioactive cement (100% bioactive cement).

While Fig. 2 shows the second tooth form implant 200 having a pair of root structures, it will be understood that the second tooth form implant 200 can have only a single root structure. — The implants may be designed with more than one root. As long as the path of insertion is not hindered by their divergence and assuming that having multiple roots would be beneficial in stabilizing the implant. In some cases, it may be beneficial to fabricate an implant with fewer roots or reduce the curvature of the roots to facilitate the implantation process.

Fig. 3 illustrates a third tooth form implant 300 in the form of a molar tooth implant. The third tooth form implant 300 has a first portion 302 at a first end 304 and a second portion 306 at an opposing second end 308. The first portion 302 resembles the root portion of the tooth, while the second portion 306 resembles the crown portion of the tooth. As described herein, the third tooth form implant 300 is constructed in view of the anatomy of the patient and in particular, the size and shape of the third tooth form implant 300 is intended to mimic the tooth that had been extracted or is otherwise missing. In one exemplary embodiment, the height (length) of the first portion 202 is between about 12 mm to about 18 mm and the height (length) of the second portion 206 is between about 3 mm and about 8 mm. The width (apex to cervix) can be between about 1 mm to about 13 mm.

In accordance with one embodiment of the present invention, the third tooth form implant 300 is defined by a core 310 and an outer layer 320 that surrounds the core 310. The outer layer 320 can at least substantially cover the entire outer surface of the core 310. Like the previous embodiments, the core 310 is formed of a biocompatible, bioactive cement. The core 310 can be formed 100% of the biocompatible, bioactive cement.

The thickness of the core 310 is typically greater than the thickness of the outer layer 320. For example, the thickness of the core 310 can be between about 1 mm to about 10 mm, while the thickness of the outer layer 320 can be between about 500 μπι and about 1500 μπι.

The core 310 can be formed of a biocompatible, bioactive cement that is suitable for the intended application described herein. The core 310 can be formed 100% of the biocompatible, bioactive cement, preferably, Biodentine® material as described above.

The outer layer 320 is formed of the biomimetic composite material described above. More specifically, the biomimetic composite material is made of a calcium silicate-based cement material (e.g., Biodentine® material) and processed dentin material from an extracted tooth (from either the patient, an animal, or a donor/cadaver).

The relative amounts of the dentin and bioactive cement within the biomimetic composite material can vary depending upon the particular application and based on other considerations. For example, the dentin can comprise from about 10 percent to about 50 percent by weight of the total biomimetic composite material. In one embodiment, the ratio of dentin to the bioactive cement is about 1 :1. However, it will be appreciated that the percentage of dentin can be greater than 50%.

In an alternative embodiment, the third tooth form implant 300 is only made up of the core 310. In other words, the third tooth form implant 300 is made entirely from the bioactive cement (100% bioactive cement).

While Fig. 3 shows the third tooth form implant 300 having a pair of root structures, it will be understood that the third tooth form implant 300 can have either one, two or three root structures.

Figs. 8A-8D illustrate other exemplary tooth form implants formed of the materials described herein and by the methods of manufacture described herein.

Manufacturing Methods

The above-described tooth form implants can be manufactured using any number of different suitable techniques. Additive Manufacturing Technique

Figs. 4 and 9 illustrate one exemplary process for manufacturing a customized tooth form implant in accordance with the present invention and more particularly, an additive manufacturing process can be used as part of the manufacturing method.

Fig. 9 is a flowchart showing exemplary steps involved with a first method 400 for manufacturing a customized tooth form implant. The first method 400 includes a first step 410 of performing a CBCT/3D imaging of a tooth that is to be replaced by the customized tooth form implant. The imaging results are stored in a computer file or the like.

As is known in the art, dental cone beam computed tomography (CT) is a special type of x-ray equipment used when regular dental or facial x-rays are not sufficient. This technology allows three dimensional (3-D) images of teeth, soft tissues, nerve pathways and bone to be produced in a single scan. It will be understood that other types of imaging can be used in order to generate a customized computer-generated model of a person's tooth.

In a second step 420, an additive manufacturing process (3D print mold) is used to produce a customized mold 405 that is shown in Fig. 4 as is based upon the imaging performed in step 410. The customized mold 405 is formed of a first mold cavity 407 (i.e., a first mold half) and a second mold cavity 409 (i.e., a second mold half). As is known in the art, when the first and second mold cavities are combined, a complete mold 405 is formed with the hollow cavities of the mold defining the space that receives the material that forms the tooth form implant and thus is formed using additive manufacturing (3D printing) so as to match the shape and size of the tooth to be replaced with the customized tooth form implant.

One or both of the first mold cavity 407 and second mold cavity 409 includes an inlet port for injecting material into the mold 405 when it is in the closed position.

In a third step 430, the biomimetic composite material that is described above is prepared. In order to process the dentin, the extracted tooth is subjected to a process that grinds and sterilizes the extracted tooth. One exemplary technique and equipment are available from KometaBio and is marketed under the product name Smart Dentin Grinder. This protocol and equipment allow autologous dentin to be produced. By grinding the extracted tooth, dentin in particle form is produced and is subsequently used in making the composite material. In one embodiment, the dentin particles can have a particle size of from about 50 microns to about 1500 microns. The particle orientation and shape at this time is variable. Typically, the particles appear wedge shaped with varying surface topography.

Once the dentin is processed, the bioactive cement is added to processed dentin according to a desired ratio and other ingredients, such as water, are added where required. The mixing of the materials involves using traditional suitable equipment, such as a dental triturator.

In one example, the mixing process includes the following steps:

1. 700.2 mg of dentin powder is added to 700mg of cement powder in capsule. 2. This capsule is then placed in a dental triturator and mulled for 10 seconds to mix the two powder components.

3. The capsule is then removed from the triturator and 7 drops of liquid from pipette are added to the capsule.

4. The capsule is then placed back in the triturator and triturated at a minimum speed of 4,000 rpm for 30 seconds.

5. The contents of the capsule are then removed with a spatula and packed into the cylindrical mold.

6. The composite material is allowed to set (harden) for 15 minutes and is then removed for further testing.

Alternative methods may include: (a) mixing the dentin particles thoroughly with

Biodentine putty/paste immediately after traditional cement trituration; (b) coating the dentin particles around Biodentine putty /paste at the walls of the mold after cement trituration; (c) mixing two capsules. The first capsule would have the dentin material added as in the example given above. Once the composite material is mixed it would be applied to the walls of the mold. Next, the second capsule of pure cement material would be mixed following the Septodont protocol. This pure cement putty/paste can be loaded into the middle of the mold filling any voids and forming the pure cement core.

Fig. 5 illustrates an alternative technique to using a dental triturator. More specifically, Fig. 5 shows a device 460 that is formed of a first syringe 462 and a second syringe 464 that are configured to interlock with one another. The first syringe 462 contains the bioactive cement (e.g., in paste form) and the second syringe 464 contains the processed dentin particles. The bioactive cement and dentin particles are thus added to the back end of the separate syringes 462, 464 to a specific measurement. The two syringes 462, 464 are attached to each other and the two materials can be mixed manually until a uniform composite mixture is formed.

In a fourth step 440, the materials used to form the tooth form implant are added to the mold 405. When the tooth form implant includes both a core formed of the bioactive cement only and an outer layer formed of the composite material, the composite material is added to the open first and second mold cavities 407, 409 so as to effectively coat the exposed surfaces that are within the respect cavities and which define the outer surfaces of the tooth form implant. The composite material is then allowed to set so as to form a hardened coating within the mold cavities.—The material may not need to be fully set before closing the mold and adding the core material. Both options may be possible. Next, the two mold cavities 407, 409 are closed so as to define a hollow space inside of the set composite material. The bioactive cement is then added through the inlet port into this hollow space inside of the set composite material, thereby forming the core of the tooth form implant. The core and outer layer are bonded to one another to form a solid implant.

In a fifth step 450, the new tooth construct (tooth form implant) is then implanted into the patient's mouth. One of the advantages of the present invention is that in the event that the processed dentin comes from the patient his or herself, all of the foregoing steps 410-440 can be done at the time of the tooth extraction. Moreover, the new tooth construct is customized for the specific patient.

It will be appreciated that the above-described additive manufacture process can be described as creating a negative of the tooth construct (i.e., the mold), an additive manufacturing process can be used to generate and form the positive of the tooth and then the mold can be made using a suitable molding material, such as putty or elastomeric materials to form a mold identical or similar to the one illustrated herein. In other words and with some similarity to the steps disclosed in Fig. 9, this alternative method can include a first step of performing a CBCT/3D imaging of a tooth that is to be replaced by the customized tooth form implant. The imaging results are stored in a computer file or the like. It will be understood that other types of imaging can be used in order to generate a customized computer-generated model of a person's tooth.

In a second step, an additive manufacturing process (3D print mold) is used to produce a customized tooth (positive 3D print of the tooth) and then a custom mold can be fabricated using a mold material, such as putty or an elastomeric material, that is placed over the 3D printed tooth. This mold is then used in the manner described herein to form the custom tooth implant.

Moreover, an extrusion-based technique (e.g., FDM -fused deposition modeling or bioplotters) can be used to form ("print") the composite materials (tooth form implants) directly without the use of a mold. This technique involves two low temperature print heads to print both the cement core and the composite surface layer. In other words, one print head can be used for formation of the cement core and the second print head can be used for formation of the composite surface layer.

Custom Milling Technique

Figs. 6A-6C and 10 illustrate another exemplary process for manufacturing a customized tooth form implant in accordance with the present invention and more particularly, a custom milling process can be used as part of the manufacturing method.

Fig. 10 is a flowchart showing exemplary steps involved with a second method 500 for manufacturing a customized tooth form implant. The second method 500 includes a first step 510 of performing a CBCT/3D imaging of a tooth that is to be replaced by the customized tooth form implant. The imaging results are stored in a computer file or the like. As with the previous method, other imaging techniques can be used.

In a second step 520, the extracted tooth is subjected to a process that grinds and sterilizes the extracted tooth and more particular, a Smart Dentin Grinder and the KometaBio protocol can be used to form the processed dentin in particulate form.

In a third step 530 and with reference to Fig. 6A, a dentine block 532 is formed by casting the composite material of the present invention into a rectangular mold with a mount 534 present that will allow for attaching into a milling machine. The mount 534 can be a metal mount/jig that is configured for insertion into a milling unit to secure the cast (dentine) block 532. The mold (rectangular mold) that is used to cast the dentine block 532 is constructed to be slightly larger than the tooth to be replaced. In a fourth step 540, the hardened composite dentine block 532 is loaded into a milling unit and based on data from the imaging of step 510 (e.g., CAD data), the 3D custom tooth form implant is milled from the composite dentine block 532 as shown in Fig. 6B.

In a fifth step 550, the custom tooth form implant formed by milling is then implanted and as mentioned with respect to the previous embodiment, the implantation, at least in one embodiment, can be performed at the time of extraction. As shown in Fig. 6C, the supporting mount 534 can be removed prior to or during insertion of the custom tooth form implant.

Elastomeric Casting Technique

Figs. 7 and 11 illustrate one exemplary process for manufacturing a customized tooth form implant in accordance with the present invention and more particularly, an elastomeric casting process can be used as part of the manufacturing method.

Fig. 11 is a flowchart showing exemplary steps involved with a third method 600 for manufacturing a customized tooth form implant.

The third method 600 includes a first step 610 of extracting the failed tooth. In a second step 620, the extracted tooth is placed into an elastomeric impression material or putty to create a negative mold 615, shown in Fig. 7, and then the extracted tooth is removed when impression material (putty) is set. Fig. 7 shows the mold 615 which can be formed of a first mold cavity (first mold half) 617 and a second mold cavity (second mold half) 619.— In this process, the set impression material is sectioned into two pieces with a blade and the original tooth is removed. It is important to split the material as cleanly and evenly (down the long axis) of the tooth as possible. This should help to form two relatively uniform halves.

In a second step 520, the extracted tooth is subjected to a process that grinds and sterilizes the extracted tooth and more particular, a Smart Dentin Grinder and the KometaBio protocol can be used to form the processed dentin in particulate form. Next, the processed dentin material (particles) are mixed with the bioactive cement to form the biomimetic composite material of the present invention.

In a third step 530, the composite material (dentin/Biodentine) is placed into the impression mold 615 and in particular, is placed into the hollow space of the first mold cavity 617 and is placed into the hollow space of the second mold cavity 619. The composite material is then allowed to set to form the hardened, cast tooth form implant.

In a fourth step 540, the custom tooth form implant is then implanted and as mentioned with respect to the previous embodiment, the implantation, at least in one embodiment, can be performed at the time of extraction. The potential applications of the present invention could be for use as a temporary (transitional) or long term dental implant to immediately replace extracted teeth and/or a novel biocompatible composite material used as a fixation device, bone void filler, or osseoinductive material in alveolar bone and tissue regeneration.

This technology can be applied to satisfy many unmet market needs in the field of dental implantology. The present method and composite material would allow for a safer and more affordable procedure that can be performed by more providers to a wider range of patient populations. It has potential applications as an immediate implant in multiple age groups (especially patients between the ages of 6-21 years of age), numerous clinical scenarios, and can be commercialized globally due to the nature and availability of the materials, rapid chairside fabrication methods, and the relatively inexpensive cost of materials, equipment, and training.

This technology involves the use of a composite material composed of a person' s (e.g., a patient's) processed tooth material being combined with a commercially available bioactive and biocompatible cement material in order to fabricate customizable patient specific tooth implants to immediately replace failing teeth.

Alternative Implant Fabrication

In yet another alternative fabrication method that is illustrated in Fig. 12, a tooth implant 700 is shown. The tooth implant 700 fabrication process begins with the extraction of the tooth of the patient and then the internal aspect (discussed herein as being the core) of the patient' s extracated tooth can be grinded away and a sterilization protocol discussed herein is followed (e.g., the sterilization protocol discussed herein with respect to the residual shell can be used) to sterile the tooth which is now in the form of a hollow tooth shell. In one embodiment, as shown in Fig. 12, the shell can be formned of the outer enamel layer 710 and the dentin layer 720. This intermediate structure can be considered to be a shell since the tooth has been hollowed out and only an outer tooth structure remains with a center void being created in the extracted tooth.

It will also be understood that in another embodiment, after extraction, the tooth can be prepared as by removing the enamal portion of the tooth leaving a dentin shell (dentin layer 720) to be processed. The shell can be processed so that a good coronal tooth structure remains intact in that the enamel layer is removed and the tooth shell is prepared for receiving a conventional crown, while also being hollow out to the tip of the root. It will also be unbderstood that one or more sections of the coronal portion may need to be removed due to decay or trauma, etc.

This alternative fabrication method is followed instead of grinding the dentin into particulate form prior to chemical sterilization. Once the fabricated hollow tooth shell is sterilized and the tubules are patent and free of debris, a bioactive cement (described herein) is extruded directly into the hollow interior of the shell and allowed to set, thereby forming a core 730 of the tooth implant 700. It will be seen that the prepared tooth has been drilled from the top down to create the hollow shell and therefore, one or more holes are formed along the top portion of the tooth (i.e., the hole extends through the dentin layer and enamel layer when present) and therefore, as shown in Fig. 12, a top surface of the core 730 may be visible along top surface of the coronal portion of the tooth.

The bioactive cement flows into the dentinal tubules thus creating another composite dentin/cement zone around the the cement core 730. The result is a fabricated implant 700 similar to the ones described herein. The combined shell and core 730 thus define the tooth implant that can be implemtned into a site at which a tooth has been extracted.

It will also be undersood that in the event that the enamel layer has been removed, a fabricated over layer for placement over the dentin layer may be contemplated and used (e.g., an outer layer such as the ones described herein).

In addition, the use of lasers, such as an Nd:YAG laser (e.g., PerioLase MVP07 from Millenium Dental Technologies), can be used with a variety of settings (ablation, biostimulation, etc.) directly into the extraction socket of the patient or focused directly on the dentin shell itself (see above description). Laser exposure can assist in decontaminating the extraction socket or tooth construct and also can help to promote periodontal regeneration by adjustment of the setting of the laser used (e.g., wavelength, duration, frequency of pulsed doeses, and angulation of the laser to create specific surface patterning).

Shape of the Tooth Form Implant

It will be appreciated that the shape and construction of the new tooth form implant can be modified slightly in order to improve the path of insertion or increase its stability in the extraction socket. This is particularly useful for teeth with multiple roots or irregular curvatures. For example, a tooth that originally had three roots could be replaced by a two- rooted implant assuming the implant remains stable in the socket or a tooth with a curve at the apex (root tip) could be designed with a decreased curvature; or an extraction socket that is irregular due to bone loss or trauma could be stabilized by altering the shape of the implant (in CAD) to fill the irregular void.

Surface Modification of Implant

In yet another aspect of the present invention, surface modification can be performed on the implant (and/or the implant site as discussed below) at the time of implant placement (to promote periodontal regeneration / healing as well as to obtain other benefits).

There are a number of different types of surface modifications that can be performed at this time. For example, such surface modifications include the use of commercially available dental products applied to the implant construct surface (or the extraction socket) to promote periodontal healing. Thus, in one embodiment, a portion or the entire surface of the formed implant (e.g., one of the ones disclosed herein) can be modified. Applicant contemplates an improvement in terms of proliferation and viability of pertinent cell types responsible for periodontal regeneration when certain suitable biologic agents are

supplemented at the implant/bone interface. Some of these products/biologies include Emdogain (EMD), Gem21s (PDGF), Bone morphogenic proteins (BMP), Amniospark (amnion growth factor liquid), autologous Platelet rich plasma (PRP) and/or Platelet rich fibrin (PRF) that when applied, may have an effect on pertinent cell types in direct contact with the implant surface.

In addition, polymeric delivery systems can be combined with these commonly used growth factors to control the release and enhance the efficacy of these surface modifications. Examples of these delivery systems can include newly developed biomaterials (i.e. hydrogels, polymeric films, nano or microspheres, and coatings) in combination with previously identified growth factors (i.e., Enamel matrix derivatives, PDGF, FGF or others mentioned above) on pertinent cell types in direct contact with the implant surface.

Compression Testing

Compression testing of these samples were conducted using an MTS (Sentech 5/D Model) mechanical tester using a 5000 lb. (approximately 23,000N) load cell at NJCBM. This is a slightly different model than what was used by Septodont, (the MTS Model 2/M, identified in the Biodentine Scientific File). In order to properly relate our findings to what was reported by Septodont, the present composite materials were tested against controls made of pure Biodentine cement. Typical compressive strength readings for the pure cement samples, measured as stress at yield, ranged between [115 - 137 MPa] (megapascals) and the amount of force applied, measured as load at yield, ranged from [10,151 - 11,679 N] (newtons). The most recent tests of our composite samples with the highest dentin composition (1 :1 or 50% dentin particle to 50% cement powder) resulted in compressive strength ranging between [88 - 126 MPa] with a load at yield between [7031 - 10,315 N]. In comparison to human masticatory forces, the load applied during routine chewing has been typically reported in the literature between [80 - 300 N] with the highest bite forces recorded ranging between [300 - 900 N].

It will be understood that the composite implants described herein can have the capacity to form a new periodontal attachment during healing or ankylose. In other words, the composite implant may fuse directly to the jawbone.

Notably, the figures and examples above are not meant to limit the scope of the present invention to a single embodiment, as other embodiments are possible by way of interchange of some or all of the described or illustrated elements. Moreover, where certain elements of the present invention can be partially or fully implemented using known components, only those portions of such known components that are necessary for an understanding of the present invention are described, and detailed descriptions of other portions of such known components are omitted so as not to obscure the invention. In the present specification, an embodiment showing a singular component should not necessarily be limited to other embodiments including a plurality of the same component, and vice- versa, unless explicitly stated otherwise herein. Moreover, applicants do not intend for any term in the specification or claims to be ascribed an uncommon or special meaning unless explicitly set forth as such. Further, the present invention encompasses present and future known equivalents to the known components referred to herein by way of illustration.

The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying knowledge within the skill of the relevant art(s) (including the contents of the documents cited and incorporated by reference herein), readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present invention. Such adaptations and modifications are therefore intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance presented herein, in combination with the knowledge of one skilled in the relevant art(s).

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It would be apparent to one skilled in the relevant art(s) that various changes in form and detail could be made therein without departing from the spirit and scope of the invention. Thus, the present invention should not be limited by any of the above-described exemplary

embodiments, but should be defined only in accordance with the following claims and their equivalents.