Patent Application
20110256498
The present invention generally relates to a filling cavities in teeth for the dental arts. More particularly, the present invention is a dental tool having a light transmittable tip portion to accommodate the transmission of light used for photo curing a composite filling while the dental tool tip portion concurrently forms the composite into a desired position simultaneously with the curing light transmitted therethrough the dental tool tip portion to allow the composite curing to be a more controlled process for the desired forming of the composite in relation to the tooth.
Dental fillings have been commonly used for centuries to fill cavities in teeth. Traditionally, amalgam fillings were commonly used as dental fillings for decades. Amalgam fillings include two or more metals of which one is mercury usually in the range of 40-50 percent. While these fillings have been in common use for over 150 years, there are a number of concerns with the use of mercury. Mercury, while generally considered safe for use in dental amalgams, does raise safety concerns both in use and in disposal later. Also, amalgam fillings permanently weaken the brittle crystalline structure of the tooth as the void left by cavity preparation is a permanent removal of integral material strength for the tooth, wherein the amalgam filling does not replace the void with a structurally integral element as the amalgam does not bond with the tooth as it must be retained with features to hold it in the tooth, further amalgam tends to discolor over time as well as being undesirably noticeable or visible, being typically bright silver in color that is in stark contrast to the near white tooth enamel color.
Composite fillings have become more popular replacing amalgam fillings as being much more structurally sound when disposed within the prepared cavity of the tooth, as the composite bonds as against the prepared cavity surfaces, thus helping to restore the structural integrity of the tooth that is lost to the prepared cavity to nearly that of a non cavity tooth. Composite fillings are typically a mixture of acrylic resins and glass-like powders. These fillings can be self hardening, that can require the mixing of substances-increasing the chances for undesirable air pocket porosity in the filling mixture, thus the use of a composite that doesn't require mixing is preferred, however, requiring to be cured with the use of ultraviolet light rays.
Composite fillings can be matched closely with the color of existing teeth, thus desirably rendering them practically invisible in relation to the tooth they are disposed in, further composite fillings are relatively durable and moderate in price. However, negatives are that the placement of the composite fillings into the cavities of the tooth can be difficult in order to eliminate any air pocket porosity or other voids where bacteria might be able to grow, or causing increased tooth hot and cold sensitivity, and further causing weakness in the combined tooth/composite structure.
Other types of tooth fillings include resin-reinforced glass ionomer fillings, porcelain fillings, ceramics, cast gold, and others. These fillings have a variety of problems associated with them and typically are not as commonly used as composites which are becoming the de-facto preferred standard tooth filling.
The process of filling a cavity with a composite filling requires initial preparation of the cavity by removing any decay, then cleaning and completely drying the cavity. Then thin layers of the composite filler material, being approximately one millimeter in thickness, are applied repeatedly with photo curing of each layer prior to the application of the next layer. Once the cavity has been filled with the layers of composite filling polymer, the final layer is shaped to the desired result in substantially conforming to the tooth outer surface, any excess composite material is trimmed and the final result is polished to achieve a smooth transition from the composite filling surface to the native tooth enamel surface.
The layers of composite polymer are each hardened within the prepared tooth cavity through photo-polymerization via the application of external energy, i.e. typically in the form of light. This process entails the use of a focused beam of light, usually ultraviolet or visible light. Typically, an ultraviolet light beam is focused on the applied layer of composite polymer which activates the resin causing the layer to harden. The composite polymer will shrink some during the photo-polymerization process, being typically about 2-6% which is undesirable in increasing the risk of air pocket porosity in the composite and weakened bonding as between the composite and the prepared tooth cavity. Since voids in the cavity can lead to bacteria growth, or causing increased tooth hot and cold sensitivity, and further causing weakness in the combined tooth/composite structure, thus it is critical to eliminate any such voids.
This results in the need for multiple thin layers of the composite polymer. Also, the polymer must be manipulated into the prepared cavity which is typically difficult to reach and relatively small in volume to ensure that no voids are created in the filling, all of which requires about 50% more time usually in completing the tooth filling with composites as compared to the prior art amalgam fillings that typically require less time to complete the tooth filling. Skilled dentists can ensure that the composite polymer material is properly applied by the feel of the dental tools in applying and manipulating the polymer material in the cavity as well as by visual inspection of the site.
The composite filling material curing light optimally should be positioned as close as possible to the composite material for maximum effectiveness, being a difficult task as the composite material is usually in a hard to reach location. Further, most conventional dental tools are formed from stainless steel or plastic materials and these materials reflect or otherwise interfere with the ultraviolet or visible light rays used to cure the composite filling material that not only causes inappropriate curing, but can also create damage to surrounding tissue in the mouth. Thus, conventional dental tools are typically not able to be used during the actual photo-curing process, resulting in the conventional dental tool and the curing light having to be used independently of one another, resulting in composite forming and curing having to be done as two separate operations, wherein if the dental tool could simultaneously form the composite to the prepared cavity while curing the chance of voids in the composite would be reduced along with less time being required via performing the two operations of forming and curing at the same time.
Another problem that often occurs with the conventional dental tool stainless steel and plastic materials is the adhesion of composite fill material to those materials while trying to form the composite filling material into layers within the prepared cavity. This creates additional problems in attempting to compact and shape the fill material not only during the curing process but even before the cure process. The adhesion of the composite fill material to the tool causes ripping of the material from the cavity and the creation of voids in the fill, often resulting in a greater chance of undesirable air pocket porosity and added time to complete the composite filling of the tooth. Furthermore, an added wetting agent is used to reduce the composite from tending to stick to the dental tool, however, this being undesirable due to the wetting agent interfering with the desired dry prepared cavity for composite bonding and again the added time to deal with the wetting agent as being an added step in the composite tooth filing process.
The present invention provides dental tools that can be safely used to manipulate and compact composite polymer fillings not only prior to the curing process but during the curing process. The dental tool does not distort or reflect the transmission of ultraviolet or visible light used to cure the polymers in the cavity. The ability on the dental tool to be used during the photo-curing process enables the composite polymer to be compacted and shaped as the polymer shrinks during curing-being about in the range of 2-6%, thus minimizing the occurrence of voids in the filling and weakened bonding between the composite and the prepared tooth cavity. This increases the efficiency of the process, reducing the time the patient must endure the filling process and minimizing the possibility of bacteria growth and infections.
The dental tool of a preferred embodiment of the present invention uses a tool tip that has at least a portion formed from a material that allows the transmission of ultraviolet wavelengths (200-400 nm) and visible wavelengths (380-760 nm) through the portion of the tool tip without distortion or reflection of the wavelengths. This reduces the risk of damage to the tooth or surrounding tissue. The material also has a relatively high tensile strength so not to break or shatter during use. The entire tool tip may be formed from this material, or only the working portion of the tool tip may be formed from this material.
In one preferred embodiment, the tool tip of the dental tool is formed from sapphire. Sapphire has a high degree of transmission of wavelengths in the 150-800 nm range. Sapphire also has a relatively high tensile strength (275-400 MPa) compared to most optical materials, so that it is durable and resistant to shattering or breaking during use. While sapphire (Al2O3) is found naturally, it is also able to produced artificially at a reasonable cost. It may also be grown, formed or machined into different shapes as well. The entire tool tip may be formed from sapphire or only the working area of the tool tip may be formed from sapphire.
The dental tool of a preferred embodiment provides a plurality of tool tips that may be attached to a gripping member. This enables the tool tips to be selected for particular uses while other tool tips have other uses. It also enables the tool to be used with opaque tool tips when a photo-curing process is not being used. The tool may also include tool tips on opposing ends of the tool so that the tool can simply be reversed when another tool tip is needed.
The dental tool of a preferred embodiment is used during a photo-curing filling process. For example, the cavity of a tooth is prepared for filling by removing decay and shaping the cavity. Then a thin layer of composite polymer fill material is applied to the cavity by the dental tool (or another dental tool). An light beam of ultraviolet (or visible light) wavelength is then directed to the fill material in the cavity. The dental tool is then used to further compact and shape the fill material as the fill material shrinks during the photo-curing process. The light beam is able to safely pass through the tool tip with only minimal distortion or reflection. Previously, the fill material would shrink and create voids in the fill material as it was unsafe to use existing tools. Then the dentist would attempt to fill the voids with additional fill material and to further shape the fill material. The tool of the present invention enables the fill material to be compacted and shaped while it is curing and shrinking. This provides a much more efficient process and one that minimizes the occurrence of voids in the fill material and provides better bonding between the composite and the prepared tooth cavity.
The tool of the preferred embodiment increases the efficiency of the cavity filling process. The ability to compact, manipulate and shape the fill material before and during the photo-curing process to eliminate voids from occurring while the material shrinks during the curing process greatly speeds up the fill process. Previous tools could not be used during the curing process so that voids would occur when the fill material shrank. The fill material would then have to be applied to the voids and cured, which could result in more voids occurring. This increases the time necessary to fill the cavity, decreasing the productivity of the dentist and increasing the discomfort to the patient. The tool of the present invention decreases the amount of time necessary to fill the cavity by allowing the fill material to be compacted and shaped during the photo-curing process. The ability of the tool to shed the fill material also increases the efficiency since the fill material will remain in place in the cavity.
These and other objects of the present invention will become more readily appreciated and understood from a consideration of the following detailed description of the exemplary embodiment(s) of the present invention when taken together with the accompanying drawings, in which;
Starting with
Further,
Moving onward,
Continuing,
Further,
Continuing,
A preferred embodiment of the present invention 50 is illustrated in
The present invention provides a tool 50 or 55 that can be used for manipulating and compacting composite fill materials 315 in a cavity 310 of a tooth not only prior to the curing process but also during the actual curing process. The dental tool 50 is used with ultraviolet (light in the range of ten (10) to four hundred (400) nm) as well as visible light (light in the range of three hundred eighty (380) to seven hundred sixty (760) nm) photo curing operations generated from the photo-curing apparatus 250. The tool 50 of the present invention includes at least a portion of the tool 105 that is able to allow ultraviolet rays to pass 260 through without distortion. This allows the tool 50 to be used even while the photo-curing operation is occurring so that the fill material 315 can be evenly compacted to eliminate voids 316 during curing. The fill material 315 may shrink during the photo-curing process, thus causing voids 316 in the fill 315 that can lead to bacteria and other problems. The present invention 50 is able to minimize the occurrence of voids 316 by continuing to compact and manipulate the fill material 315 during the curing process while shrinkage may occur. Previous tools were unable to do this as the ultraviolet rays 260 would be distorted and reflected causing damage to the surrounding tissue.
The translucent tool tip portion 105 not only is able to transmit 260 the ultraviolet rays without distortion, it must also be sufficient strength to be durable and hard to compact and manipulate the fill material 315 without shattering or causing damage to the patient 300. The tool tip portion 105 of the present invention 50 also has the ability to easily shed or not adhere to the composite fill material 315, that is, the composite fill material 315 does not stick to the tool 105 pulling the composite fill material 315 away from the prepared cavity 310 of the tooth. This further minimizes the occurrence of voids 316 in the cavity 310 since the fill material 315 will remain in place once it has been compacted and shaped.
The present invention 50, as set forth in the claims, is directed to dental tools that provide the characteristics, either individually or in combination with one another, of allowing the transmission 260 of visible and ultraviolet wavelengths, durability and strength so that the tool 105 is able to compact the fill material 315 to eliminate voids 316, and to properly shape the fill 315 material, and non-adhesion of the fill material 315 to the tool 105. The claimed invention encompasses not only present materials that meet one or more of these characteristics but materials that may be developed as well that meet one or more of these characteristics.
In a preferred embodiment, discussed in greater detail below, the tool 50 is formed, at least in part, from sapphire for the tip portion 105. It is to be expressly understood that the present invention is not limited to this material, but includes others as well. Sapphire is described herein as one material that meets the scope of the present invention.
Sapphire is an anisotropic, rhombohedral structure of the crystalline form of aluminum oxide (Al2O3). It occurs naturally but is also able to be synthetically created on an industrial scale. It has a high degree of transmission within the ultraviolet and visible light spectrum while possessing a high degree of strength and toughness as well as chemical resistance and composite fill material does not adhere easily to sapphire. Sapphire is able to transmit wavelengths between two hundred (200) nm to seven hundred sixty (760) nm, and even up to five (5) μm without significant distortion. It also has a compressive strength of 20,000 kg/cm2, with a tensile strength of 7,000 kg/cm2, and a fracture toughness in the range of 2.4-4.5 MPA√M (Pascals per square root meters). Sapphire also has the characteristic of being slick, that is, most materials including composite fill materials 315 will not easily stick or adhere to it. It also has a high abrasion resistance so it will not easily scratch which could cause distortion or reflection of wavelengths.
This provides a high strength, hard, and durable tool 105 that is capable of allowing ultraviolet rays to transmit 260 through without distortion or reflection. This allows the tool 105 to be used during the photo-curing process so that voids 316 are minimized, the composite fill material 315 can be more precisely shaped-even with composite shrinkage during curing, and the 310 cavity filling process be more efficiently conducted so that the patient 300 spends less time undergoing the process and ending up with a better quality filling that minimizes the loss of structural integrity of the tooth from the filling and provides for an almost visually imperceptible filling. The ability of the tool 105 to be used during the photo-curing process to prevent voids 316 from occurring as the material 315 shrinks, as well as the ability of the tool 105 to shed the fill material 315 so that it remains in place in the cavity 310 increases the efficiency of the process. The sapphire tool is also useful prior to the photo-curing process in placing the fill material 315 in the cavity, compacting the fill material 315 and shaping the fill material 315 since the fill material 315 does not adhere easily to the sapphire tool 105 and the sapphire tool 105 has high strength and durability. The details and features of the tool 105 of the present invention is discussed in greater details below in the description of exemplary embodiments.
A preferred embodiment of the present invention is illustrated in
The dental tool 50 includes a central gripping member 60 with distal tool ends 65, 70. The central gripping member 60 can be formed of suitable materials, preferably a material that can be easily sterilized and that does not degrade under ultraviolet light. In the preferred embodiment 50, the central gripping member 60 is formed of a high strength plastic with knurled portions for ease of gripping. Alternatively, the gripping member 60 could be formed from stainless steel, aluminum or other suitable materials.
The dental tool 50, of this preferred embodiment, is illustrated with opposing distal tool ends 65, 70. It is to be expressly understood that the tool could also include a single tool end as well. The tool end 65 of this preferred embodiment includes an extended distal end 75 with a reduced diameter. This reduced diameter portion 75 includes a first portion 85 that extends outwardly along the longitudinal axis 61 of the gripping member 60 for an extended length then a second portion 95 that angles upwardly for another length. The lengths and angle of these two portions are determined by the particulars of the teeth in order to easily access the cavity 310 within a particular tooth while still allowing visibility to the cavity 310. It is to be expressly understood that other lengths, angles and configurations may be used as well within the scope of the invention as claimed.
Dental tool tip portions 105, discussed in greater detail below, are secured to the tool assembly 50. The tool tip portions 105 can be formed on the tool assembly 50, permanently affixed to the tool assembly 50, or removably attached to the tool assembly 50. In one preferred embodiment, a collet chuck 185, as seen in
The opposing end 70 of the gripping member 60 similarly includes reduced diameter end portions 80, 90 that extend from the gripping member 60. These end portions may be identical to the end portions on the opposing end of the gripping member 60 or may be at differing lengths and angles to provide a different function. A collet chuck 185 may be affixed to the distal ends 65 and 70, or the tool tips 105 may be permanently affixed, as shown in
The dental tool tips 105 of the present invention are uniquely designed tools that provide a combination of high strength for performing the operations of filling, manipulating and compacting the composite fill material 315 being preferably 3M Filltek or equivalent within the prepared cavity 310 not only prior to the photo-curing operation but during the photo-curing operation as well. It is critical that the material 315 be properly compacted to eliminate voids 316 and air bubbles 316 within the fill material 315 to prevent problems from occurring later, see
The sapphire tool tip 105 can be formed into a cylindrical rod 130, see
The sapphire tool tip 105 can be formed into a variety of shapes being about its longitudinal axis 110 and configurations depending on the function to be accomplished and the tooth that is being filled. For example, as shown in
The tooth is prepared for filling by removing any decay and shaping the cavity 310 to receive the fill material 315. The fill material 315 is applied in thin (approximately one mm in thickness) layers 317 by depositing the material 315 in the cavity 310 and then manipulating it as shown in
The efficiency of the cavity filling process is increased by the use of the tool 50 or 55 and its unique combination of optical transmission 260 so that it can be used during the photo-curing process, the hardness of the tool tip 105 to compact the material 315 to prevent voids 316 from occurring and the ability to shed the fill material 315 so that the fill material 315 remains in place in the cavity 310. The ability of the tool tip 105 to be used during the photo-curing process allows the material 315 to be compacted and shaped as it shrinks to prevent voids 316 from occurring increases the efficiency over previous tools that could only be used before or independent of the photo-curing process. Voids 316 would occur with these tools as the material 315 shrinks during curing. These voids 316 would then have to be filled, thus increasing the time of the filling process. The hardness of the tool tip 105 also minimizes voids 316 as the material 315 is thoroughly compacted by the tool tip 105 before and during the curing process. The ability to shed the fill material 315 also decreases the time of the filling process as the material 315 does not easily cling to the tool tip 105 once it has been placed. Thus, the tool tip 105 of the present invention 55 or 55 increases the efficiency of the tooth cavity 310 filling process.
Looking in particular at
Accordingly, the present invention of a dental tool assembly 50 or 55 has been described with some degree of particularity directed to the embodiment(s) of the present invention. It should be appreciated, though; that the present invention is defined by the following claims construed in light of the prior art so modifications or changes may be made to the exemplary embodiment(s) of the present invention without departing from the inventive concepts contained therein.
This continuation in part (CIP) patent application claims priority from U.S. patent application Ser. No. 12/763,159 filed on Apr. 19, 2010 by Alan Wong of Federal Heights, Colo., US.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12763159 | Apr 2010 | US |
| Child | 13086057 | US |
