1. Field of the Invention
The invention relates generally to methods for designing customized dental restorations and prostheses and particularly dentures. The methods involve taking digital photographs of the patient to be fitted with the restoration or prosthesis and transferring the photographs to a computer software program. The software program uses the photographs to make certain calculations that are translated into their corresponding anterior maxillary tooth mould forms. The program prompts the dental professional to select the desired materials and structure for the denture, such as denture tooth shade, tooth arrangement, patient ridge condition, occlusal scheme, and denture base. This information is used to generate a customized prescription for the denture. The resulting prescription is sent to a dental laboratory that manufactures the denture.
2. Brief Description of the Related Art
Dental professionals use different dental prostheses or appliances to treat patients with lost teeth or tooth structure. By the terms, “prosthesis,” “restoration” “and “appliance” as used herein, it is meant a dental product that replaces or restores lost tooth structure, teeth, or oral tissue including, but not limited to, fillings, inlays, onlays, veneers, crowns, bridges, full dentures, removable partial dentures, relines of full and partial dentures, nightguards, occlusal splints, and the like. Common dental prostheses for full or partially edentulous patients include, for example, full dentures and partial dentures. The dentures are used to restore or replace the lost teeth. In general, removable partial dentures are used to replace some, but not all, of the patient's natural teeth. The partial denture includes a base having a partial set of embedded artificial teeth which rests in the edentulous space and is coupled to abutment teeth by clasps or other connectors. Full dentures, on the other hand, are used to replace all of the patient's natural teeth. A full denture includes a base having a full set of embedded artificial teeth which fits over either the upper gum tissue or lower gum tissue. Partial dentures are designed to preserve any remaining teeth along with hard and soft oral tissue. The dentures must be functional. Furthermore, the denture should enhance the dental and facial aesthetics of the patient. The denture teeth should appear natural. However, it is often difficult to make form-fitting and comfortable dentures. The process is time-consuming requiring the patient to make several dental office visits. In many instance, the dentist must reshape and adjust the denture several times before the patient is satisfied.
Today, a variety of methods are used to make dentures. In one traditional method, a dentist first takes impressions of a patient's dental anatomy. A paste-like material, such as an alginate, is placed in a standard or custom-made impression tray. The dentist inserts the tray in the mouth of a patient and he/she bites down into the tray. Separate impression trays for the upper and lower dental arches are used. The dentist allows the impression material to harden and then removes the trays from the patient's mouth. The hardened impressions are finally sent to a dental laboratory. There, a dental technician prepares models of the upper/lower dental arches by pouring dental stone into the hardened impressions. After a release coating is applied to the dental models, they are placed in a conditioning oven and warmed. A polymerizable resin used to form the baseplate is molded over the warm models. Then, the resin-coated models are placed in a light-curing unit and irradiated with light to harden the baseplate resin. After the light-curing cycle has been completed, the models are removed from the unit and allowed to cool. The hardened baseplates are removed from the respective models. It is customary for the technician to mount wax occlusal rims over the baseplates. The resulting wax rim baseplates are returned to the dentist so they can be evaluated for fit and comfort in the patient's mouth. Then, the completed occlusal registration is articulated.
Next, artificial teeth are built on the processed baseplate and wax rims using a “lost wax” process. In this method, wax is applied to the baseplate and a set of artificial teeth is positioned in the wax. The processed baseplate, with completed tooth arrangement, is placed in a flask containing an investing material. Then, the flask is heated to eliminate the wax. Upon melting, the wax flows out of the flask. Removing the wax from inside of the flask leaves an interior cavity having the shape of the denture. In a next step, a polymerizable acrylic composition is “packed into” into the interior cavity of the flask. The acrylic composition is heated so that it bonds to the teeth and baseplate. When this acrylic composition cures and hardens, it will hold the artificial teeth in position.
Designing and fabricating dentures is a complex process. Many time-consuming steps must be followed to prepare a denture having good aesthetics and mechanical properties. Artificial teeth having the proper color, shade, translucency, length, width, and geometry must be selected and incorporated into the baseplate. The process involves numerous dental professionals including dentists, dental assistants, and laboratory technicians and their work must be carefully coordinated to produce an aesthetically-pleasing and functional denture.
In recent years, computer-based systems using digital images have been developed so that certain dental prostheses can be made more efficiently in a time-saving manner. For example, Lehmann, U.S. Pat. No. 6,786,726 discloses a computer network system for making prostheses such as caps, crowns, bridges, fillings, and the like. In this method, the dental practitioner takes a digital image of the patient's tooth (resulting in a real image). A reference tooth shade (resulting in a reference image) image is also taken. The real and reference images are correlated to find a composite match number having an associated shade. The images are forwarded via computer network to a dental laboratory giving a dental technician access to the images. This allows both the dentist and technician to have simultaneous access to the images—they are able to evaluate the patient's case and develop a treatment plan together using the interactive network.
Jelonek, U.S. Pat. No. 7,035,702 discloses a method for making dental restorations involving the steps of determining the geometrical and aesthetic constraints of the restoration. These constraints are inputted into a computer to mathematically select a recipe for producing the dental restoration. A database of materials and procedures for preparing the dental restoration is compiled. Then, a recipe for making the restoration is produced from the database based on inputted data.
Taub, U.S. Pat. No. 7,33,874 discloses methods for designing and producing dental prostheses using a communication network between a dental clinic and dental laboratory. The system also includes a dental service center which is a separate entity from the dental laboratory. The service center generates a virtual 3D model of the patient's dentition from data obtained by scanning the teeth directly or by scanning a physical model of the teeth. The manufacturing of the prosthesis is shared between the service center and dental lab. The clinic sends instructions to the dental laboratory and service center. In one example, the data needed to produce the virtual 3D model is transmitted from the dental clinic or laboratory to the dental service center. A prescription specifying the teeth that are to be moved in the dental treatment as well as the final position of the teeth is sent to the service center. Then, the service center uses software to make a virtual 3D model, which is used to determine the dental appliance needed. Finally, this information is sent to the dental lab which makes the appliance.
The above-described systems may provide some advantages, but they are not used for designing and making dentures for edentulous patients, which present particular problems. As described above, in a conventional denture-making process, the dentist must manually measure the facial and oral dimensions of the patient, and selects artificial tooth colors, shades, and dimensions using manual tools such as tooth indicators, shade guides, and mould guides. Based on this information, the dentist sends a prescription for the denture to a dental laboratory. There are many variables to this process and the resulting prescription for the denture depends upon the techniques, skills, and experience level of the dental professionals. Some prescriptions will provide detailed information about the requested denture including patient's dental anatomy, baseplate materials, tooth dimensions and shapes, tooth color and shades, and the like. Other prescriptions will simply request the denture be made as the laboratory sees fit and will only provide information on the tooth shade.
The methods and system of the present invention provides the dental professional with a new chair-side method for writing denture prescriptions. The dentist can use the system to generate detailed digital prescriptions including information on facial dimensions of the patient, tooth length, width and geometry, requested composition of the artificial teeth, edentulous ridge condition and occlusal registration of the patient, denture base materials, and color and shade of the artificial teeth. The resulting prescription can be sent by e-mail, paper mail, or facsimile to a dental laboratory that will manufacture the denture. This system is easy-to-use, consistent, and time-saving for the dentist.
The novel features that are characteristic of the present invention are set forth in the appended claims. However, the preferred embodiments of the invention, together with further objects and attendant advantages, are best understood by reference to the following detailed description in connection with the accompanying drawings in which:
The present invention provides different methods for designing customized dental restorations and prostheses, particularly dentures, using digital images. Although the methods described herein primarily refer to dentures, it should be understood that other dental restorations and prostheses can be designed in accordance with the invention. Referring to
Referring to
Prior to taking the digital photographs, a grey screen reference sticker” (24) is placed on the forehead of the patient and a grey screen mouth shield” (26) is positioned inside the mouth of the patient. The sticker (24) and mouth shield (26) are used so that a grey screening and color balancing procedure can be performed as described further below. In
The color grey preferably is used for the reference sticker (24) and mouth shield (26), because it contrasts sharply with other skin colors and the patient would not normally be wearing any other grey object on his/her face when taking the photographs. In “grey screening,” the system checks to see which pixels in the input image (digital color photograph) are not grey and labels those pixels as “target” pixels. The software then blends the “input image” (patient's facial image, which is a collection of all target pixels) into a “destination image” that will appear on the computer monitor screen (21). The pixels in the grey areas are not labeled as target pixels and thus will not be blended in with the rest of the pixels constituting the facial features.
This technique of blending two images together after a color has been removed from one of the images can be referred to as chroma keying. This results in the input image (facial image) having “color voids” or “color removal points” (where pixels are missing) upon being blended into the destination image. Particularly, voids will appear in the area of the forehead (where the grey screen sticker has been placed) and area of the mouth (where the grey screen mouth shield has been inserted).
The software program first looks to the forehead area. Because the software knows the relative dimensions of the grey sticker (24), it can use this information to make key measurements of the forehead and other facial contours. In addition, the software fills in the voided mouth area with selected tooth shades and tooth forms per the methods discussed further below. That is, the practitioner can select a particular denture structure with artificial teeth and “drop” this picture into the open mouth area of the digital image. The resulting destination image with selected denture is shown to the patient. Thus, the patient can see the results of selecting a specific denture before the treatment plan is finalized. The patient can see how a particular denture structure will affect their overall appearance. The system is beneficial to the practitioner and patient, because it can simulate different treatment plans using different sets of artificial teeth.
Upon receiving the digital image, the software automatically engages in color balancing to adjust the color of the captured digital image and generate a color balanced reproduction. Color balancing techniques are known in the digital imaging industry. Color balancing is needed, because colors in the captured digital image can shift resulting in an off-color image of the subject. Color shifting can be due to a variety of reasons, for example, shadows, lighting, and backdrops used when the digital image was taken. In the method of this invention, the colors of the facial image of the patient can become distorted; thus, color balancing of the image is needed. Once the digital image has been properly color balanced, a selected artificial tooth set can be “dropped’ into the image and a denture prescription can be generated as described in more detail below. In the color balanced digital image, the color of the selected “dropped in” tooth set is perceived correctly. That is, the color, shade, hue, brilliance, intensity, RGB values, and other characteristics of the tooth set and facial digital image match-up properly. This benefits the dental practitioner, because he/she is better able to select the most appropriate tooth shade with input from the patient. The practitioner and patient can better visualize which tooth shade is the most natural looking.
It is recognized that other imaging techniques can be used in accordance with this invention. For example, a “green-screening” system can be used, wherein the reference sticker (24) and mouth shield (26) are green colored. However, a “green-screening” system is less preferred, because there can be problems with color balancing and the captured digital image may be off-color.
In addition to the color balancing step, the software automatically formats the digital image to the correct size, and the formatted, color-balanced image appears on the monitor screen (21) so that the practitioner can view it easily. The software program then identifies the key facial contours, for example, chin, temple, vertical midline, and horizontal plane across the pupils. It is important that vertical and horizontal reference planes of the patient's face be considered so that an aesthetically-pleasing denture with artificial teeth having proper occlusion can be made. The program identifies the vertical midline and horizontal plane across the pupils as shown in
Referring back to the block diagram in
In accordance with this invention, the dental practitioner uses a tangible, hand-held shade guide (not shown) to select the most appropriate tooth color and shade. As noted above, shade guides are well known in the dental industry. The shade guides include removable colored tabs. The colored tabs come in a variety of shades resembling the appearance of natural teeth. Each shade provides a unique enamel translucency, color blending, and contrasting colors between neck and body of the artificial tooth. To determine the appropriate tooth shade for a given patient, the practitioner removes one of the tabs and holds it up in the mouth of the patient. Together, the practitioner and patient decide upon the appropriate tooth shade. In making this decision, the practitioner and patient address such questions as: Which tooth shade is the most natural looking? Which tooth shade will complement the patient's natural features? And, which tooth shade will enhance cosmetic appearance? The selected tooth shade from the given tooth shade guide is then entered. The software program may provide a drop-down menu on the monitor screen (21) listing each of the predetermined tooth shades for a given shade guide. The practitioner can enter the desired shade by simply scrolling down the menu and clicking on the shade guide in this predetermined set. For example, the Portrait IPN dental shade guide includes 27 translucent shades ranging from shades designated as “P1 to P81. ” If the practitioner and patient decide that “P2” tooth shade is the best match, the practitioner can enter this shade into the program. In turn, the program can generate an image simulating a denture with the selected tooth shade. Thus, the patient can see the effect of selecting a specific tooth shade and how this shade will impact their appearance. The program also can provide side-by-side comparisons of a denture made with a first tooth shade against a denture made with a second and different tooth shade. These images should be used for comparison references only. In considering which tooth shade would provide the best aesthetics for a given patient, the practitioner should use an actual hand-held tooth shade guide as described above.
Next, the program recommends a denture tooth mould form that will be used for making the denture. The mould form is chosen based on facial contours, tooth measurements, patients ridge condition, and tooth shades entered according to the steps described above. Moulds for making teeth are well known and include the Bioform® mould system; and Biostabil®, Monoline®, Anatoline®, and Euroline® posterior mould forms, available from Dentsply. As indicated, the moulds are available in anterior and posterior forms. The anterior moulds are used for producing the anterior teeth (central incisors, lateral incisors, and canines), while the posterior moulds are used for producing the posterior teeth (premolars and molars). For example, if the Portrait IPN tooth shade guide (as discussed above) is used, there are 62 anterior mould and 27 posterior occlusal mould forms available based on the Bioform mould system (tapered at angles of 0, 10, 20, 22, 33, and 40 degrees) that can be used. On the other hand, if the Bioblend IPN tooth shade guide (as discussed above) is used, there are 58 upper and lower anterior mould form options and 4 posterior occlusal mould forms available. The appropriate artificial tooth mould form for making the denture can be recommended from these sets and displayed on the computer screen allowing the practitioner to select there from.
In one preferred embodiment, in the anterior region, at least two, and more preferably, three tooth mould form options are provided by the software program. The user can enter the desired anterior mould form based on these predetermined select options. Referring to
Following the functional steps illustrated in
In addition, the practitioner enters the desired occlusal scheme for the patient. Several occlusal scheme select options can be provided by the software as shown in the computer screen shot of
The material that will be used to make the denture is also entered. The practitioner can work with the patient in making this decision or accept the default selections made by the program. A set of predetermined denture base materials preferably is loaded in the software program and appear as select options on the computer screen as shown in
It should be understood that the functional steps shown in the block diagram of
Mandibular
The resulting customized digital prescription can be sent by e-mail, facsimile, paper mail, or other means to a dental laboratory that will manufacture the denture. In addition, a copy of the digital prescription can be provided to the patient for his/her records. The dental laboratory can use conventional techniques to fabricate the denture as prescribed. In
The methods and systems of this invention provide the dental practitioner with a new tool for designing and making dentures. As described above, the dentist can use the system to generate customized digital prescriptions. In addition, the system can be used as a tutorial for patients and staff in the dental office. For practitioners, the system offers many benefits including a quick and accurate means for prescribing dentures and recording the prescriptions. The system helps the practitioner by providing a step-by-step guide to designing a customized denture for a given patient. The practitioner is led step-by-step through the procedure.
Particularly, the system provides reference points across the facial digital image(s) of the patient so that the dentist can more accurately identify facial contours. Based on this information, the system automatically provides facial and tooth measurements and provides suggestions for tooth shade and denture base shade. Furthermore, the system prompts the practitioner by asking key questions such as: What is the edentulous ridge condition of patient? What is the occlusal scheme? What is the desired tooth arrangement? This helps the practitioner design a close fitting and comfortable denture. The resulting denture helps enhance the appearance of the patient and is fully functional. The system also helps facilitate two-way communication between the practitioner and patient. Rather than the practitioner deciding on the make and style of the denture and dictating this to the patient one-way, the patient is invited to participate in the process. The patient is asked for input on the desired tooth shade and denture base shade along with other decision points. Thus, the system is more interactive—the practitioner and patient are more engaged in the process. Each person feels that he/she has more input and control over the design and fabrication of the denture.
Persons skilled in the art will appreciate that various modifications can be made to the illustrated embodiments and description herein without departing from the spirit and scope of the present invention. It is intended that all such modifications within the spirit and scope of the present invention be covered by the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
4583947 | Hazar | Apr 1986 | A |
4681543 | Monroy | Jul 1987 | A |
5011405 | Lemchen | Apr 1991 | A |
5027281 | Rekow et al. | Jun 1991 | A |
5055039 | Abbatte et al. | Oct 1991 | A |
5139419 | Andreiko et al. | Aug 1992 | A |
5273429 | Rekow et al. | Dec 1993 | A |
5395238 | Andreiko et al. | Mar 1995 | A |
5452219 | Dehoff et al. | Sep 1995 | A |
5691905 | Dehoff et al. | Nov 1997 | A |
5718585 | Dehoff et al. | Feb 1998 | A |
5798924 | Eufinger et al. | Aug 1998 | A |
5851115 | Carlson et al. | Dec 1998 | A |
5879158 | Doyle et al. | Mar 1999 | A |
5882192 | Bergusen | Mar 1999 | A |
5975893 | Chisti et al. | Nov 1999 | A |
6007332 | O'Brien | Dec 1999 | A |
6049743 | Baba | Apr 2000 | A |
6068482 | Snow | May 2000 | A |
6089868 | Jordan et al. | Jul 2000 | A |
6152731 | Jordan et al. | Nov 2000 | A |
6200278 | Arnett | Mar 2001 | B1 |
6227850 | Chisti et al. | May 2001 | B1 |
6244861 | Andreiko et al. | Jun 2001 | B1 |
6250918 | Sachdeva et al. | Jun 2001 | B1 |
6309215 | Phan et al. | Oct 2001 | B1 |
6318994 | Chishti et al. | Nov 2001 | B1 |
6358047 | Lehman | Mar 2002 | B2 |
6464496 | Sachdeva et al. | Oct 2002 | B1 |
6688885 | Sachdeva et al. | Feb 2004 | B1 |
6786726 | Lehman et al. | Sep 2004 | B2 |
7001178 | Grunenfelder et al. | Feb 2006 | B2 |
7029275 | Rubbert et al. | Apr 2006 | B2 |
7035702 | Jelonek et al. | Apr 2006 | B2 |
7064830 | Giogianni et al. | Jun 2006 | B2 |
7118374 | Culp | Oct 2006 | B2 |
7128573 | Pameijer et al. | Oct 2006 | B2 |
7156655 | Sachdeva et al. | Jan 2007 | B2 |
7215803 | Marshall | May 2007 | B2 |
7333874 | Taub et al. | Feb 2008 | B2 |
7474932 | Geng | Jan 2009 | B2 |
7590462 | Rubbert et al. | Sep 2009 | B2 |
7711252 | Konno et al. | May 2010 | B2 |
7717708 | Sachdeva et al. | May 2010 | B2 |
8092220 | Wiedmann | Jan 2012 | B2 |
20020010568 | Rubbert et al. | Jan 2002 | A1 |
20020025503 | Chapoulaud et al. | Feb 2002 | A1 |
20040152036 | Abolfathi et al. | Aug 2004 | A1 |
20040248066 | Recigno | Dec 2004 | A1 |
20080060652 | Selvarajan et al. | Mar 2008 | A1 |
20080195418 | Parker et al. | Aug 2008 | A1 |
20080270175 | Rodriguez et al. | Oct 2008 | A1 |
20100323329 | Adusumilli et al. | Dec 2010 | A1 |
20100332253 | Adusimilli et al. | Dec 2010 | A1 |
20110045442 | Adusimilli et al. | Feb 2011 | A1 |
Number | Date | Country |
---|---|---|
0360657 | Mar 1990 | EP |
0502227 | Nov 1996 | EP |
1486901 | Dec 2004 | EP |
1935369 | Jun 2008 | EP |
8603292 | Jun 1986 | WO |
9102955 | Mar 1991 | WO |
9111959 | Aug 1991 | WO |
9515731 | Jun 1995 | WO |
9703622 | Feb 1997 | WO |
9832394 | Jul 1998 | WO |
9934747 | Jul 1999 | WO |
0016045 | Mar 2000 | WO |
0026847 | May 2000 | WO |
0147405 | Jul 2001 | WO |
0151005 | Jul 2001 | WO |
2005008441 | Jan 2005 | WO |
2007084727 | Jul 2007 | WO |
2007103303 | Sep 2007 | WO |
2008039544 | Apr 2008 | WO |
Number | Date | Country | |
---|---|---|---|
20100076581 A1 | Mar 2010 | US |
Number | Date | Country | |
---|---|---|---|
61205797 | Jan 2009 | US | |
61130622 | Jun 2008 | US |