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EP-4346691-B1 - ORTHODONTIC TUBES AND MANUFACTURE OF PATIENT-SPECIFIC ORTHODONTIC TUBES

EP4346691B1EP 4346691 B1EP4346691 B1EP 4346691B1EP-4346691-B1

Inventors

  • VANNOY, SAMUEL
  • WINCHELL, DYLAN
  • FAFARA, Kelsey, A.
  • DUGGAN, OISIN
  • GRIFFIN, Alfred, Charles, III

Dates

Publication Date
20260506
Application Date
20220527

Claims (13)

  1. A method of manufacturing customized orthodontic tubes (1300, 1300') for patients, the method comprising: obtaining a three-dimensional (3D) model of one or more teeth of a patient; generating a 3D model of an orthodontic tube structure using the 3D model of the one or more teeth of the patient, the orthodontic tube structure comprising: a debonding structure that facilitates debonding of an orthodontic tube from a tooth of the patient, wherein the debonding structure comprises a ridge (1316, 1316', 2000) in the 3D model of the orthodontic tube structure, and wherein the ridge is proximate an interface of a base (1304, 1304') of the tube and a face (1308, 1308') of the tube, and wherein the ridge is at least partially on the circumferential surface of the base of the tube; and using an additive manufacturing device to produce a customized orthodontic tube based on the 3D model of the orthodontic tube structure.
  2. A customized orthodontic tube (1300, 1300') produced by an additive manufacturing device using a 3D model of an orthodontic tube structure generated using a 3D model of one or more teeth of a patient, the customized orthodontic tube comprising: a debonding structure that facilitates debonding of the customized orthodontic tube from a tooth of the patient, wherein the debonding structure comprises at least one ridge (1316, 1316', 2000), and wherein the ridge is proximate an interface of a base (1304, 1304') of the tube and a face (1308, 1308') of the tube, and wherein the ridge is at least partially on the circumferential surface of the base of the tube.
  3. The method of claim 1 or the customized orthodontic tube of claim 2, wherein at least a portion of the debonding structure has a customized shape based on a 3D model of at least one of the one or more teeth.
  4. The method of claim 1 or the customized orthodontic tube of claim 2, wherein the debonding structure comprises a stress concentrator (1320) in a portion of the orthodontic tube structure.
  5. The method or customized orthodontic tube of claim 4, wherein the stress concentrator is shaped such that the customized orthodontic tube fractures when a normal force applied to the stress concentrator.
  6. The method or customized orthodontic tube of claim 4, wherein the stress concentrator runs along an occlusal-gingival direction of the orthodontic tube structure.
  7. The method or customized orthodontic tube of claim 4, wherein the stress concentrator includes a portion with a profile that is substantially triangular cross-section.
  8. The method of claim 1, wherein a height of the ridge varies along a mesial-distal axis of the orthodontic tube structure.
  9. The customized orthodontic tube of claim 4, wherein the customized orthodontic tube further comprises: a base (1304'); and two portions (1308a, 1308b); wherein: the stress concentrator (1320) comprises an approximately V-shaped space between the two portions; and a vertex of the approximately V-shaped space is proximate the base.
  10. The customized orthodontic tube of claim 9, wherein: each of the two portions comprises a substantially flat wall on a respective side of the approximately V-shaped space.
  11. The customized orthodontic tube of claim 2, wherein the face comprises a slot opening sized for an arch wire to be inserted through the slot.
  12. The customized orthodontic tube of claim 2, wherein the customized orthodontic tube comprises two portions (1308a, 1308b) separated, at least in part, by a space (1320), and the at least one ridge comprises a first ridge and a second ridge, wherein: a first ridge is located on a first one of the two portions; and a second ridge is located on a second one of the two portions, preferably wherein the space separating the two portions is a stress concentrator.
  13. The customized orthodontic tube of claim 2, further comprising: multiple portions each comprising a respective slot extending through the portion, preferably wherein slots of the multiple portions are aligned such that arch wire passes through the slots of the multiple portions.

Description

FIELD An embodiment of present invention relates generally to the manufacturing of ceramic labial/lingual orthodontic tubes for straightening the teeth and correcting malocclusion. More specifically, an embodiment of the invention relates to the methodology of direct manufacture of customized labial/lingual orthodontic tube by using a ceramic slurry-based additive manufacturing (AM) technology. BACKGROUND Orthodontics has been widely adapted in clinics to correct malocclusion and straighten teeth. The traditional method is to adhere preformed brackets and tubes onto the teeth and run elastic metal wires of round, square, or rectangular cross-sectional shape through the tube slots to provide the driving force. The adaptation of the bracket and tube to the individual tooth is performed by filling the gap between the tooth surface and bracket and tube surface with adhesive. This thereby bonds the brackets and tubes to the tooth such that the bracket and tube slots, when the teeth are moved to their final position, lie in a near flat (depending on manufacturing accuracy) horizontal plane. US2009017411A1A describes a ceramic orthodontic bracket which has a centrally located clip for retaining an archwire in an archwire slot. WO2019210015A1 describes a method of manufacturing customized ceramic labial/lingual orthodontic brackets by additive manufacturing. US2019377327A1 describes a method of manufacturing pre-formed, customized, ceramic, labial/lingual orthodontic clear aligner attachments by additive manufacturing. SUMMARY The invention is defined by the appended independent claims. Certain embodiments are defined in the dependent claims. Some embodiments of the present invention provide improved techniques for creating custom lingual or labial ceramic orthodontic tubes, and which provides the capability for in-office fabrication of such tubes. Pre-formed edgewise tubes may have no prescription, requiring adjustment of the archwire. Alternatively, the edgewise tubes may have an idealized prescription of angulation, inclination, or in/out variation for specific teeth in what is referred to as a "straight-wire appliance". Because the tube pad is typically not custom made for an individual patient's tooth, the clinician is responsible for the tube placement, which may introduce a source of error, which commonly increases patient visits and overall treatment time. These tubes are typically off-the-shelf products. A misplacement in bonding a tube to a tooth can be corrected by compensation bends in the wire or by debonding and repositioning of the tube, both of which increase time and cost. Custom metal lingual tubes are currently available that are fabricated at a central location from 3D scans or impressions of the dentition and mailed back to the clinician and transferred to the patient via indirect bonding. Selective laser melting (SLM) is a 3DAM technique that has been used to create custom metal lingual brackets and tubes (for example, see US Pat. No. 8,694,142), but this technique suffers from insufficient resolution and surface finish. While true custom labial tubes have been used, custom positioning of a standard, non-custom tube can be created via indirect bonding which itself has inherent error within the tube itself. Many current true custom labial systems (SURESMILE™ Inc.) rely heavily on putting custom bends in the wire based on a 3D scan rather than creating a true straight-wire appliance. For example, US Pat. No. 8,690,568 provides for a method to weld a metal bracket slot to a stock metal bracket base into a custom position, but does not describe a method for creating a custom bracket base or to create an aesthetic, non-metal bracket. These partially custom metal brackets and tubes (akin to tubes) suffer from inaccuracy in slot position and premature debonding due a stock base that doesn't match the tooth morphology, and are unappealing to older patients who prefer to have non-metal appliances for aesthetic concerns. Ceramic brackets have been commercially available and studied since the 1980s and are a desirable material compared to metal brackets due to their excellent esthetics, resistance to creep, rigidity, biocompatibility, corrosion resistance, stability in the oral environment and non-toxic nature. However, non-customized ceramic tubes have only been available since 2018 as the need for an aesthetic alternative to metal is not as concerning to patients due to their location in the bracket of the mouth. Ceramic brackets and tubes are predominantly manufactured by injection molding, which has manufacturing limitations. For example, it may be difficult or impossible to use injection molding to create undercuts that may enhance a tube's mechanical bond strength to a tooth adhesive. Ceramic tubes, unlike metal, do not bend in order to debond but instead the connection between the tube and the bonding material must be broken. Due to the mechanical properties of ceramic and this debond mechanism, t