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Title:
PEDIATRIC AND VETERINARY PRE-MADE DENTAL CROWNS
Document Type and Number:
WIPO Patent Application WO/2012/134449
Kind Code:
A1
Abstract:
Dental crowns with an optional retention system and methods for installing the dental crowns are described. The dental crowns are formed of alumina, zirconia toughened alumina, glass infiltrated magnesium alumina, leucite reinforced glass ceramic, ceria-stabilized zirconia/alumina nanocomposite, or lithium disilicate glass ceramic. The dental crowns have an open interior cavity with an exposed surface into which the retention system which includes one or more shaped grooves can be integrated. The open interior cavity is sized to be mated to a prepared oral surface and the exposed surface of the open interior cavity with the integrated retention system is used to bond the dental crown to the prepared oral surface. Kits including various crown shapes in multiple sizes as well as methods for installing the crowns are also described.

Inventors:
PETTINATO, Frank (4427 Rowan Rd, New Port Richey, Florida, 34653, US)
Application Number:
US2011/030336
Publication Date:
October 04, 2012
Filing Date:
March 29, 2011
Export Citation:
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Assignee:
TUFF KID CROWNS LLC (4427 Rowan Rd, New Port Richey, Florida, 34653, US)
PETTINATO, Frank (4427 Rowan Rd, New Port Richey, Florida, 34653, US)
International Classes:
A61C5/08; A61C13/08; A61C13/23; A61L27/02
Foreign References:
US20100028835A12010-02-04
US20060154211A12006-07-13
US5584693A1996-12-17
KR20100060828A2010-06-07
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Claims:
WHAT IS CLAIMED IS:

1. An apparatus for use as a pediatric or veterinary dental crown comprising:

a pre -made dental crown, the dental crown being formed of alumina, zirconia toughened alumina, glass infiltrated magnesium alumina, leucite reinforced glass ceramic, ceria-stabilized zirconia/alumina nanocomposite, or lithium disilicate glass ceramic, and including an outer surface and an open interior cavity with an exposed surface for use in bonding to an oral surface.

2. The apparatus of claim 1, further comprising a retention system integrated into the exposed surface of the open interior cavity of the dental crown, the retention system including a shaped groove formed on the exposed surface of the open interior cavity of the dental crown.

3. The apparatus of claim 2, wherein the shaped groove is a generally horizontal groove around the periphery of the exposed surface of the open interior cavity of the dental crown.

4. The apparatus of claim 2, wherein the shaped groove is a plurality of parallel grooves around the periphery of the exposed surface of the open interior cavity of the dental crown.

5. The apparatus of claim 2, wherein the shaped groove is curved.

6. The apparatus of claim 2, wherein the shaped groove is s-shaped.

7. The apparatus of claim 2, wherein the shaped groove is a plurality of grooves.

8. The apparatus of claim 7, wherein the plurality of grooves comprises s-shaped grooves.

9. The apparatus of claim 7, wherein the plurality of grooves comprises a combination of straight and s-shaped grooves.

10. The apparatus of claim 8, wherein the s-shaped grooves are oriented vertically.

11. The apparatus of claim 8, wherein the s-shaped grooves are oriented vertically and horizontally.

12. The apparatus of claim 1, wherein the dental crown is in the shape of a molar and includes a retention system integrated into the exposed surface of the open cavity of the dental crown, the retention system comprising a plurality of s-shaped grooves oriented vertically and horizontally.

13. The apparatus of claim 1, wherein the dental crown is in the shape of a canine, lateral incisor, or central incisor and includes a retention system integrated into the exposed surface of the open cavity of the dental crown, the retention system comprising a plurality of s-shaped grooves and straight grooves.

14. The apparatus of claim 1, wherein the dental crown is formed over a base material.

15. The apparatus of claim 14, wherein the base material is a metal or zirconium oxide.

16. The apparatus of claim 1, wherein a veneer layer is placed over the surface of the crown.

17. A kit comprising multiple sizes of a dental crown according to claim 1 in the shape of one or more of a molar, canine, lateral incisor, or central incisor.

18. A kit comprising multiple sizes of a dental crown according to claim 1 in the shapes of canines, lateral incisors, and central incisors.

19. A method for providing a pediatric or veterinary dental crown for a natural tooth:

preparing an oral surface to receive a dental crown;

selecting a dental crown from a set of pre-fabricated crowns comprising dental crowns of various sizes, the dental crowns being formed of alumina, zirconia toughened alumina, glass infiltrated magnesium alumina, leucite reinforced glass ceramic, ceria-stabilized

zirconia/alumina nanocomposite, or lithium disilicate glass ceramic, and including an outer surface and an open interior cavity with an exposed surface for use in bonding to the prepared tooth;

applying an adhesive to the exposed surface of the open interior cavity of the selected dental crown; and

seating the dental crown on the oral surface.

20. The method of claim 19, wherein the dental crown further comprises a retention system integrated into the exposed surface of the open cavity of the dental crown, the retention system including a shaped groove formed on the exposed surface of the open interior cavity of the dental crown.

21. The method of claim 20, wherein the shaped groove is a generally horizontal groove around the periphery of the exposed surface of the open interior cavity of the dental crown.

22. The method of claim 20, wherein the shaped groove is a plurality of parallel grooves around the periphery of the exposed surface of the open interior cavity of the dental crown.

23. The method of claim 19, wherein the shaped groove is curved.

24. The method of claim 19, wherein the shaped groove is s-shaped.

25. The method of claim 19, wherein the shaped groove is a plurality of grooves.

26. The method of claim 25, wherein the plurality of grooves comprises s-shaped grooves.

27. The method of claim 25, wherein the plurality of grooves comprises a combination of straight and s-shaped grooves.

28. The method of claim 26, wherein the s-shaped grooves are oriented vertically.

29. The method of claim 26, wherein the s-shaped grooves are oriented vertically and horizontally.

30. The method of claim 19, wherein the dental crown is in the shape of a molar and includes a retention system integrated into the exposed surface of the open cavity of the dental crown, the retention system comprising a plurality of s-shaped grooves oriented vertically and horizontally.

31. The method of claim 19, wherein the dental crown is in the shape of a canine, lateral incisor, or central incisor and includes a retention system integrated into the exposed surface of the open cavity of the dental crown, the retention system comprising a plurality of s-shaped grooves and straight grooves.

32. The method of claim 19, wherein the dental crown is formed over a base material.

33. The method of claim 32, wherein the base material is a metal or zirconium oxide. The method of claim 19, wherein a veneer layer is placed over the surface of the crown.

Description:
Pediatric and Veterinary Pre-made Dental Crowns

BACKGROUND

When a crown is needed for an adult tooth, the crown is created based on the shape of the existing tooth. As an example, an impression of the existing tooth can be created then dimensions can be taken from the impression. A crown is then custom fabricated in a lab, e.g., using CAD/CAM technology, to match the existing tooth. This process, as described for an adult, requires multiple dental office visits. In children's dentistry, this approach is neither well received by the patient nor economical. Typically, visiting a dentist for dental work is not an enjoyable experience for a child, so a process requiring multiple visits, e.g., a first visit to create an impression so that a custom crown can be created then another visit to install the crown, is not psychologically desirable. Additionally, the child's baby tooth will be lost as the child's permanent tooth comes in, thus an expensive custom created crown is uneconomical.

To overcome these drawbacks related to children's crowns, stock sets of crowns with multiple sizes of each tooth have been created. These sets have been created using various materials such as stainless steel and veneered stainless steel. As can be imagined, a stainless steel crown is quite visible in a child's mouth and many parents prefer to avoid such an obvious crown. Veneered stainless steel crowns, e.g., porcelain veneers, are designed to avoid being obvious, but the veneers are susceptible to cracking and being otherwise damaged due to the normal forces exerted during chewing. Adult crowns have also been made from these materials, but the dental industry has evolved to use different materials. For example, adult crowns are often made from porcelain or other hard, but millable, materials such as zirconia.

SUMMARY

Dental crowns formed of alumina, zirconia toughened alumina, glass infiltrated magnesium alumina, leucite reinforced glass ceramic, ceria- stabilized zirconia/alumina nanocomposite, or lithium disilicate glass ceramic are described. The dental crowns include an outer surface and an open interior cavity with an exposed surface for use in bonding to an oral surface. The dental crowns may optionally include a retention system integrated into the exposed surface of the open interior cavity of the dental crown. The retention system includes a shaped groove formed on the exposed surface of the open interior cavity of the dental crown. The crowns can be used in pediatric and veterinary applications. The crowns can be provided in kits including multiple sizes of molars, canines, lateral incisors, and/or central incisors.

Methods for providing a dental crown for a natural tooth are also described. The methods include preparing an oral surface to receive a dental crown. The dental crown is selected from a set of pre-fabricated crowns comprising dental crowns of various sizes. The pre-fabricated dental crowns are formed of alumina, zirconia toughened alumina, glass infiltrated magnesium alumina, leucite reinforced glass ceramic, ceria-stabilized zirconia/alumina nanocomposite, or lithium disilicate glass ceramic and include an outer surface and an open interior cavity with an exposed surface for use in bonding to the prepared tooth. The pre-fabricated dental crowns may optionally include a retention system integrated into the exposed surface of the open cavity of the dental crown. The retention system includes a shaped groove formed on the exposed surface of the open interior cavity of the dental crown. Once a dental crown in selected, an adhesive is applied to the exposed surface of the open interior cavity of the selected dental crown and the dental crown is seated on the prepared oral surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a cross-sectional view of a crown.

Figs. 2A-G show various shaped grooves that can be formed in the exposed surface of the interior cavity of the dental crown. Fig. 2A shows an s-shape; Fig. 2B shows a horizontal linear shape, a vertical linear shape, and a linear shape at another angle; Fig. 2C shows a rotated s- shape; Fig. 2D shows a combination of an s-shape and a vertical linear shape; Fig. 2E shows two parallel horizontal linear shapes; Fig. 2F shows a combination of two s-shapes and a vertical linear shape; Fig. 2G shows a combination of two s-shapes and a rotated s-shape; and Fig. 2H shows an interlocking system of s-shapes.

Fig. 3A-C show cross-sectional views of a central incisor crown showing a useful retention system. Fig. 3A shows a cross-sectional lingual view of a first s-shaped groove on the inner side of the exposed surface of the interior cavity of the dental crown, Fig. 3B shows a cross-sectional buccal view of a second s-shaped groove on the outer side of the exposed surface of the interior cavity of the dental crown, and Fig. 3C shows a cross-sectional interproximal view of a first vertical linear groove on one side of the exposed surface of the interior cavity of the dental crown (a second vertical linear groove is also located on the opposite interproximal side).

Figs. 4A-C show cross-sectional views of a lateral incisor crown showing a useful retention system. Fig. 4A shows a cross-sectional lingual view of a first s-shaped groove on the inner side of the exposed surface of the interior cavity of the lateral incisor dental crown, Fig. 4B shows a cross-sectional buccal view of a second s-shaped groove on the outer side of the exposed surface of the interior cavity of the lateral incisor dental crown, and Fig. 4C shows a cross- sectional interproximal view of a first vertical linear groove on one side of the exposed surface of the interior cavity of the lateral incisor dental crown (a second vertical linear groove is also located on the opposite interproximal side).

Figs. 5A-C show cross-sectional views of a canine crown showing a useful retention system. Fig. 5A shows a cross-sectional lingual view of a first s-shaped groove on the inner side of the exposed surface of the interior cavity of the canine dental crown, Fig. 5B shows a cross- sectional buccal view of a second s-shaped groove on the outer side of the exposed surface of the interior cavity of the canine dental crown, and Fig. 5C shows a cross-sectional interproximal view of a first vertical linear groove on one side of the exposed surface of the interior cavity of the canine dental crown (a second vertical linear groove is also located on the opposite interproximal side).

Figs. 6A-C show cross-sectional views of a molar crown showing a useful retention system. Fig. 6A shows a cross-sectional lingual view of first and second s-shaped grooves on the inner side of the exposed surface of the interior cavity of the molar crown, Fig. 6B shows a cross-sectional buccal view of third and fourth s-shaped grooves on the outer side of the exposed surface of the interior cavity of the molar crown, and Fig. 6C shows a cross-sectional

interproximal view of a first sideways s-shaped groove on one side of the exposed surface of the interior cavity of the molar crown (a second sideways s-shaped groove is also located on the opposite interproximal side).

Figs. 7A-C show cross-sectional views of a molar crown showing a useful retention system. Fig. 7A shows a cross-sectional lingual view of first and second horizontal linear grooves on the inner side of the exposed surface of the interior cavity of the molar crown, Fig. 7B shows a cross-sectional buccal view of the first and second horizontal linear grooves on the outer side of the exposed surface of the interior cavity of the molar crown, and Fig. 7C shows a cross-sectional interproximal view of the first and second horizontal linear grooves on one side of the exposed surface of the interior cavity of the molar crown.

DETAILED DESCRIPTION

Dental crowns, for example, for use in pediatric dentistry, and methods for installing the dental crowns are described. The dental crowns are formed of alumina, zirconia toughened alumina, glass infiltrated magnesium alumina, leucite reinforced glass ceramic, ceria-stabilized zirconia/alumina nanocomposite, or lithium disilicate glass ceramic. The dental crowns have an outer tooth shaped surface and an open interior cavity with an exposed surface. The open interior cavity is sized to be mated to a prepared oral surface and the exposed surface of the open interior cavity is used to bond the dental crown to the prepared oral surface. The dental crowns as described herein may optionally include a retention system integrated into the exposed surface of the open interior cavity. The retention system includes one or more shaped grooves created in the exposed surface of the open interior cavity of the dental crown.

The methods for installing the dental crowns as described herein include preparing an oral surface, such as a tooth, to receive a dental crown. Next a dental crown is selected from a set of pre-fabricated crowns comprising dental crowns as described herein of various sizes. Once a dental crown is selected, an adhesive is applied to the exposed surface of the open interior cavity of the selected dental crown which optionally includes an integrated retention system. Then the dental crown is seated onto the oral surface. When included, the integrated retention system increases the stability of the bonded dental crown by improving the crowns ability to resist movement in multiple directions, e.g., from pushing, pulling, twisting, compressing, grinding, or rotating.

The dental crowns as described herein are formed from alumina, zirconia toughened alumina, glass infiltrated magnesium alumina, leucite reinforced glass ceramic, ceria-stabilized zirconia/alumina nanocomposite, or lithium disilicate glass ceramic.

Alumina for use as a dental crown as described herein comprises aluminum oxide (AI 2 O 3 ). Alumina is a substantially pure material, i.e., no intentionally added stabilizing or other materials, formed by oxidizing aluminum, i.e., heating aluminum in the presence of oxygen. The outside surface of an alumina crown can be covered with a layer of dental porcelain, e.g., feldspar ceramic masses. Additionally, the alumina can be formed over a metal, e.g., platinum, core to form a veneered crown. Examples of commercially available pre-made alumina milling blanks for use in dental applications include Procera® pre-made alumina milling blanks (Nobel BioCare; Yorba Linda, CA) and In-Ceram® pre-made alumina milling blanks (Sirona Dental Systems; Charlotte, NC).

Zirconia toughened alumina for use as a dental crown as described herein comprises alumina (aluminum oxide) containing between 0.1% to 49% zirconia (zirconium oxide). A zirconia toughened alumina for use as described herein can contain between 5% to 40% zirconia, 8% to 30% zirconia, 10% to 25%, or 16% to 20% zirconia. Additional minor stabilizing dopants for either alumina or zirconia known to those skilled in the art, such as magnesium, calcium, yttrium, cerium, indium, aluminum, scandium, ytterbium, halfnium, or chromium, and oxides or mixtures thereof, can be included in the zirconia toughened alumina. An example of a commercially available pre-made zirconia toughened alumina for use in dental applications is VITA In-Ceram® (Al 2 0 3 /Zr0 2 ) which is available in milling blocks (Sirona Dental Systems; Charlotte, NC).

Glass infiltrated magnesium alumina for use as a dental crown as described herein comprises a system utilizing a magnesium alumina base material. The magnesium alumina is cast into a useful form and heat-treated, or sintered, and then a glass infiltrate is applied and the form is heat-treated again. The process creates the glass-infiltrated magnesium alumina material. An example of a commercially available pre-made glass infiltrated magnesium alumina for use in dental applications is VITA In-Ceram® Spinell which is available in milling blocks (Sirona Dental Systems; Charlotte, NC).

Leucite reinforced glass ceramic for use as a dental crown as described herein comprises traditional dental ceramics formed with leucite to modify the ceramic 's coefficient of thermal expansion. An example of a leucite reinforced glass ceramic useful with the crowns described herein includes IPS Empress CAD (Ivoclar Vivadent Inc; Amherst, NY). Leucite reinforced glass ceramic materials can be used over cores of, for example, zirconium oxide, to form veneered crowns.

Ceria- stabilized zirconia/alumina nanocomposite for use as a dental crown as described herein comprises ceria-stabilized Zr0 2 /Al 2 0 3 nanocomposite (also known by the acronyms Ce- TZP/A and Ce-TZP/ A1 2 0 3 ). An example of a ceria-stabilized zirconia/alumina nanocomposite useful with the crowns described herein includes NanoZir™ (Matsushita Electric Works; Osaka, Japan). The disclosed compounding ratio for NanoZir™ is 70% Ce-TZP and 30% A1 2 0 3 ;

however, other ratios of Ce-TZP to A1 2 0 3 are useful, such as 50:50, 55:45, 60:40, 61 :39, 62:38, 63:37, 64:36, 65:35, 66:34, 67:33, 68:32, 69:31, 71 :29, 72:28, 73:27, 74:26, 75:25, 76:24, 77:23, 78:22, 79:21, 80:20, 81 : 19, 82:18, 83: 17, 84: 16, 85: 15, 86: 14, 87: 13, 88: 12, 89: 11, 90: 10, 91 :9, 92:8, 93:7, 94:6, 95:5, 96:4, 97:3, 98:2, or 99:1 depending upon the types of physical properties are desired.

Lithium disilicate glass ceramics for use as a dental crown as described herein comprise Li 2 Si 2 C>5 and L1 3 PO 4 crystal matrices. An example of a lithium disilicate glass ceramic useful with the crowns described herein includes IPS E.max® (Ivoclar Vivadent Inc; Amherst, NY), which is available in pressable ingots (IPS E.max® Press) or crystalline intermediate phase blocks that can me milled then crystallized (IPS E.max® CAD). Lithium disilicate glass ceramic materials can be used over cores of, for example, zirconium oxide, to form crowns.

Crowns made from these materials can be formed in various ways including placing a substantially pure alumina, zirconia toughened alumina, glass infiltrated magnesium alumina, leucite reinforced glass ceramic, ceria-stabilized zirconia/alumina nanocomposite, or lithium disilicate glass ceramic in a mold to form the specific shape desired for a crown, then the crown can be hardened by sintering. These crowns can be formed by pouring, placing, or pressing a material into a mold. An example of a commercially available pressing device and firing furnace includes the Programat EP3000 from Ivoclar Vivadent Inc. (Amherst, NY). Ivoclar Vivadent Inc. also makes a ceramic furnace called Programat P300/G2 useful for sintering ceramics.

Additionally, a crown can be milled from a pre-formed solid piece of alumina, zirconia toughened alumina, glass infiltrated magnesium alumina, leucite reinforced glass ceramic, ceria- stabilized zirconia/alumina nanocomposite, or lithium disilicate glass ceramic. Various preformed milling blanks of such materials as well as computer controlled milling machines are commercially available. Milling blanks are typically available in various sizes. Prior to milling into crown shapes, the milling blanks can be hardened, for example, by sintering, e.g., for 6.5 hours at 1,530 degrees Celsius. After sintering, the crowns can be colored and glazed. Examples of commercially available computer controlled milling machines include Dental Mill (Digital Dental Lab; Laguna Hills, CA), Procera® (Nobel BioCare; Yorba Linda, CA), Everest® (Kavo Dental; Lake Zurich, IL), Lava™ (3M ESPE; St. Paul, MN), Precident System (DCS Dental; Allschwil, Germany), Cercon® Smart Ceramic System (Dentsply Ceramco; York, PA), Hint- ELs® DentaCAD Systeme (Hint-ELS; Griesheim. Germany), Denzir™ (Decim AB; Skelleftea, Sweden), and the CEREC® inLab (Sirona Dental Systems; Charlotte, NC). Further, crowns can be formed by casting techniques such as slip casting or lost wax casting. Various other methods of working with the materials described herein are known to those of skill in the art and are intended to be included herein.

The outer surfaces of the dental crowns are shaped like teeth, e.g., children's baby teeth. Examples of the outer surface shapes of the dental crowns described herein include, but are not limited to, maxillary right central incisor, maxillary left central incisor, maxillary right lateral incisor, maxillary left lateral incisor, maxillary right canine, maxillary left canine, maxillary right first molar, maxillary left first molar, maxillary right second molar, maxillary left second molar, mandibular right central incisor, mandibular left central incisor, mandibular right lateral incisor, mandibular left lateral incisor, mandibular right canine, mandibular left canine, mandibular right first molar, mandibular left first molar, mandibular right second molar, and mandibular left second molar. As teeth are naturally formed in a variety of sizes, dental crowns of a variety of sizes of each outer surface shape are also included. The variation in sizes can reflect a simple proportional relationship, e.g., a second tooth is ten percent larger than a first tooth, or more sophisticated criteria can be used to establish the relationships between different sized dental crowns, e.g., a second crown is fifteen percent taller, but only eight percent wider, than a first crown to account for human tooth spacing variations. A set of pre-fabricated crowns of a specific tooth, e.g., a maxillary right central incisor, as contemplated herein can include two or more crowns of different sizes, three or more crowns of different sizes, four or more crowns of different sizes, five or more crowns of different sizes, six or more crowns of different sizes, seven or more crowns of different sizes, eight or more crowns of different sizes, nine or more crowns of different sizes, or ten or more crowns of different sizes. The variation in sizes provides a dentist with a range of options such that one of the sizes is similar enough to a patient's natural tooth size that a custom crown will not need to be formed. This range of sizes and the concomitant adaptability of the crowns to various situations will enable pediatric or veterinary dentists, for example, to fit a crown during a single dental treatment, e.g., a single office visit. In addition to different sizes of each crown tooth type, sets of dental crowns as described herein including different sizes of different combinations of crowns are also contemplated. For example, a complete set of dental crowns can include different sizes of each of a maxillary right central incisor, a maxillary left central incisor, a maxillary right lateral incisor, a maxillary left lateral incisor, a maxillary right canine, a maxillary left canine, a maxillary right first molar, a maxillary left first molar, a maxillary right second molar, a maxillary left second molar, a mandibular right canine, a mandibular left canine, a mandibular right first molar, a mandibular left first molar, a mandibular right second molar, and a mandibular left second molar. Different sub-combinations of dental crowns in multiple sizes are also possible. For example, a posterior dental crown set could include different sizes of a maxillary right first molar, a maxillary left first molar, a maxillary right second molar, a maxillary left second molar, a mandibular right first molar, a mandibular left first molar, a mandibular right second molar, and a mandibular left second molar. For further example, an anterior dental crown set could include different sizes of a maxillary right central incisor, a maxillary left central incisor, a maxillary right lateral incisor, a maxillary left lateral incisor, a maxillary right canine, a maxillary left canine, a mandibular right central incisor, a mandibular left central incisor, a mandibular right lateral incisor, a mandibular left lateral incisor, a mandibular right canine, and a mandibular left canine. Having one or more sets of crowns available will enable a dentist to quickly find a crown useful in almost every situation and will enable pediatric and veterinary dentists to complete crown installations in a single dental treatment, e.g., a single office visit.

Fig. 1 shows a cross-sectional view of a crown 10. The crown has an outer surface 20 as described above and an open interior cavity 30. The open interior cavity 30 is sized and shaped such that it will be complimentary to an oral surface that has been prepared to receive the crown 10. The size and shape of the oral surface, e.g., a tooth, prepared to receive a crown 10 will be at the discretion of the dentist according to procedures well known to those of skill in the art. The size and shape of the open interior cavity 30 will vary depending on the overall size of the crown 10 and the size of the oral surface to which it will be bonded.

A retention system is optionally integrated into the exposed surface of the interior cavity of the dental crown. The retention system consists of one or more shaped grooves formed in the exposed surface of the interior cavity of the dental crown (see Fig. 2A-H). The shaped grooves can be, for example, curved, s-shaped 40 (see Fig. 2A) or linear. Linear grooves can be horizontal 50, vertical 52, or oriented at another angle 54 (see Fig. 2B). Additionally, linear grooves can be continuous around the circumference of the interior surface of the crown or discontinuous in the form of dashes. The shaped grooves can be in a variety of orientations, e.g., a rotated s-shape 60 (see Fig. 2C), combinations (see Figs. 2D-2G), interlocking designs, e.g., interlocking s-shapes 70 (see Fig. 2H), numbers, and sizes. The retention system can, for example, include one or more horizontal grooves, two or more horizontal grooves, three or more horizontal grooves, four or more horizontal grooves, or five or more horizontal continuous or discontinuous grooves. Additionally, the dimensions of the grooves, i.e., height, width, and depth, can vary. Shaped grooves useful with the crowns described herein can be, for example, from 0.05 mm to 1 mm deep, 0.07 mm to 0.9 mm deep, 0.08 mm to 0.7 mm deep, 0.09 mm to 0.6 mm deep, 0.1 mm to 0.5 mm deep, 0.2 mm to 0.4 mm deep, or 0.25 to 0.35 mm deep. The height and/or width of shaped grooves useful with the crowns described herein can be, for example, from 2 mm to 8 mm, 3 mm to 7 mm, 3 mm to 6 mm, or 4 mm to 5 mm. For specific example, an s-shaped groove useful with the crowns described herein can be 0.3 mm deep, 6 mm high, and 3 mm wide. The linear grooves provide the greatest benefit in prevention of motion related to forces applied at a right angle to its length, i.e., a vertical linear groove would help prevent twisting motion around the axis of a bonded tooth surface. The s-shaped groves help prevent motion in effectively every direction as vector lines applied at a right angle to the s- shape occur at almost every angle. Additional shapes, e.g., circles, triangles, curves, and other letter-shapes, and combinations thereof are also useful for shaped grooves.

Specific examples of retention systems useful with the dental crowns described herein are shown in Figs. 3-6. Figs. 3A-C are cross-sectional views of a central incisor crown 300 showing a useful retention system. Fig. 3 A is a cross-sectional lingual view of a first s-shaped groove 310 on the inner side of the exposed surface of the interior cavity 320 of the central incisor crown 300. Fig. 3B is a cross-sectional buccal view of a second s-shaped groove 330 on the outer side of the exposed surface of the interior cavity 320 of the central incisor crown 300. Fig. 3C is a cross-sectional interproximal view of a first linear groove 340 on one side of the exposed surface of the interior cavity 320 of the central incisor crown 300 (a second linear groove is also located on the opposite interproximal side). Thus, a useful retention system for central incisor crowns as described herein includes two s-shaped grooves and two linear grooves. Figs. 4A-C are cross- sectional views of a lateral incisor crown 400 showing a useful retention system. Fig. 4A is a cross-sectional lingual view of a first s-shaped groove 410 on the inner side of the exposed surface of the interior cavity 420 of the lateral incisor crown 400. Fig. 4B is a cross-sectional buccal view of a second s-shaped groove 430 on the outer side of the exposed surface of the interior cavity 420 of the lateral incisor crown 400. Fig. 4C is a cross-sectional interproximal view of a first linear groove 440 on one side of the exposed surface of the interior cavity 420 of the lateral incisor crown 400 (a second linear groove is also located on the opposite

interproximal side). Thus, a useful retention system for lateral incisor crowns as described herein includes two s-shaped grooves and two linear grooves. Figs. 5A-C are cross-sectional views of a canine crown 500 showing a useful retention system. Fig. 5A is a cross-sectional lingual view of a first s-shaped groove 510 on the inner side of the exposed surface of the interior cavity 520 of the canine crown 500. Fig. 5B is a cross-sectional buccal view of a second s- shaped groove 530 on the outer side of the exposed surface of the interior cavity 520 of the canine crown 500. Fig. 5C is a cross-sectional interproximal view of a first linear groove 540 on one side of the exposed surface of the interior cavity 520 of the canine crown 500 (a second linear groove is also located on the opposite interproximal side). Thus, a useful retention system for canine crowns as described herein includes two s-shaped grooves and two linear grooves. Figs. 6A-C are cross-sectional views of a molar crown 600 showing a useful retention system. Fig. 6A is a cross-sectional lingual view of first and second s-shaped grooves 610 on the inner side of the exposed surface of the interior cavity 620 of the molar crown 600. Fig. 6B is a cross- sectional buccal view of third and fourth s-shaped grooves 630 on the outer side of the exposed surface of the interior cavity 620 of the molar crown 600. Fig. 6C is a cross-sectional interproximal view of a first sideways (i.e., horizontal) s-shaped groove 640 on one side of the exposed surface of the interior cavity 620 of the molar crown 600 (a second sideways s-shaped groove is also located on the opposite interproximal side). Thus, a useful retention system for molar crowns as described herein includes two vertical s-shaped grooves and two sideways s- shaped grooves. Figs. 7A-C are cross-sectional views of a molar crown 700 showing another useful retention system. Fig. 7A is a cross-sectional lingual view of first and second horizontal linear grooves 710 on the inner side of the exposed surface of the interior cavity 720 of the molar crown 700. Fig. 7B is a cross-sectional buccal view of the first and second horizontal linear grooves 710 on the outer side of the exposed surface of the interior cavity 720 of the molar crown 700. Fig. 7C is a cross-sectional interproximal view of the first and second horizontal linear grooves 710 on the exposed surface of the interior cavity 720 of the molar crown 700. Note in Fig. 7A-7C the horizontal grooves are continuous around the interior cavity 720 of the molar crown 700. Horizontal grooves such as those shown in Fig. 7 for molar crowns are also useful in central incisor crowns, lateral incisor crowns, and canine crowns. Thus, a useful retention system for molar crowns as described herein includes two horizontal linear grooves.

Similar retention systems using one, three, four, or five horizontal linear grooves are also useful. The molar crown retention systems as just described are equally useful in both first and second molars. Generally, the combinations of multiple s-shaped or s-shaped and linear grooves are equally useful in the maxillary, mandibular, right, and left side versions of the described central incisors, lateral incisors, canines, and first and second molars.

Methods for using the dental crowns described herein will be well known to those of skill in the art. Generally, the methods include preparing an oral surface, such as a tooth, to receive a dental crown. Next an appropriately sized dental crown as described above is selected from a kit including various sizes of the type of tooth the crown is to cover. Next an adhesive is applied to the exposed surface of the open interior cavity of the selected dental crown and the dental crown is seated on the oral surface. Adhesives useful with alumina, zirconia toughened alumina, glass infiltrated magnesium alumina, leucite reinforced glass ceramic, ceria-stabilized

zirconia/alumina nanocomposite, and lithium disilicate glass ceramic crowns are well known to those of skill in the art. The dental crowns described herein are generally useful in pediatric dentistry as they can be combined in kits with appropriate size variations to enable a dental practitioner to prepare a tooth and secure a crown in a single office visit. The same temporal and convenience issues are of concern in veterinary dentistry and the dental crowns, kits, and methods described herein would be equally useful in veterinary dentistry (with the appropriate tooth profiles for the animal at issue).

Examples

Example 1

A set of crowns will be created by programming a material compatible milling machine (e.g., a Dental Mill (Digital Dental Lab; Laguna Hills, CA), Procera® (Nobel BioCare; Yorba Linda, CA), Everest® (Kavo Dental; Lake Zurich, IL), Lava™ (3M ESPE; St. Paul, MN), Precident System (DCS Dental; Allschwil, Germany), Cercon® Smart Ceramic System

(Dentsply Ceramco; York, PA), Hint-ELs® DentaCAD Systeme (Hint-ELS; Griesheim.

Germany), Denzir™ (Decim AB; Skelleftea, Sweden), or CEREC® inLab (Sirona Dental Systems; Charlotte, NC) per material requirements/compatibility) to mill pre-sintered Procera® pre-made alumina milling blocks (Nobel BioCare; Yorba Linda, CA), VITA In-Ceram® pre- made zirconia toughened alumina milling blocks (Sirona Dental Systems; Charlotte, NC), IPS Empress CAD pre-made leucite reinforced glass ceramic milling blocks (Ivoclar Vivadent Inc; Amherst, NY), or VITA In-Ceram® Spinell pre-made glass infiltrated magnesium alumina milling blocks (Sirona Dental Systems; Charlotte, NC) to produce seven sizes each of a maxillary right central incisor, a maxillary left central incisor, a maxillary right lateral incisor, a maxillary left lateral incisor, a maxillary right canine, a maxillary left canine, a maxillary right first molar, a maxillary left first molar, a maxillary right second molar, a maxillary left second molar, a mandibular right canine, a mandibular left canine, a mandibular right first molar, a mandibular left first molar, a mandibular right second molar, and a mandibular left second molar for a total of 112 crowns. A retention system including two horizontal linear grooves is also milled into the interior surface of the dental crown. After milling, the crowns will be colored and glazed to a smooth surface.

Example 2

A set of crowns will be created by a pressing process using IPS E.max® Press pressable ingots. The crowns will be formed using a Programat EP3000 press and firing furnace from

Ivoclar Vivadent Inc. (Amherst, NY). The Programat EP3000 will produce seven sizes each of a maxillary right central incisor, a maxillary left central incisor, a maxillary right lateral incisor, a maxillary left lateral incisor, a maxillary right canine, a maxillary left canine, a maxillary right first molar, a maxillary left first molar, a maxillary right second molar, a maxillary left second molar, a mandibular right canine, a mandibular left canine, a mandibular right first molar, a mandibular left first molar, a mandibular right second molar, and a mandibular left second molar for a total of 112 crowns. A retention system including two horizontal linear grooves is also formed into the finished crowns by milling the horizontal linear grooves the interior surface of the dental crown. After milling, the crowns will be colored and glazed to a smooth surface. Example 3

A set of crowns will be created by a casting technique, e.g., slip casting. Seven sizes each of a maxillary right central incisor, a maxillary left central incisor, a maxillary right lateral incisor, a maxillary left lateral incisor, a maxillary right canine, a maxillary left canine, a maxillary right first molar, a maxillary left first molar, a maxillary right second molar, a maxillary left second molar, a mandibular right canine, a mandibular left canine, a mandibular right first molar, a mandibular left first molar, a mandibular right second molar, and a

mandibular left second molar will be cast for a total of 112 crowns. A retention system including two horizontal linear grooves is also formed into the crowns during the casting process, i.e., the casting mold includes the two horizontal linear grooves. After casting, the crowns will be colored and polished to a smooth surface.

The present invention is not limited in scope by the embodiments disclosed herein which are intended as illustrations of a few aspects of the invention and any embodiments which are functionally equivalent are within the scope of this invention. Various modifications of the dental crowns and methods for using the dental crowns in addition to those shown and described herein will become apparent to those skilled in the art and are intended to fall within the scope of the appended claims. Further, while only certain representative combinations of various aspects of the dental crowns and method steps disclosed herein are specifically discussed in the embodiments above, other combinations of the various aspects of the dental crowns and method steps will become apparent to those skilled in the art and also are intended to fall within the scope of the appended claims. Thus a combination of various aspects of the apparatus or steps may be explicitly mentioned herein; however, other combinations of various aspects of the dental crowns and steps are included, even though not explicitly stated. The term "comprising" and variations thereof as used herein is used synonymously with the term "including" and variations thereof and are open, non-limiting terms.