Orthodontic suspension bracket and method of use

Abstract

An orthodontic appliance for attachment to a tooth with adhesive is provided that resists debonding due to impact. The appliance is provided with a compliant interface between the adhesive and the point of impact. An appliance may be provided with an orthodontic bracket suspended from a mechanical bonding base that is to be secured with adhesive to a tooth. The suspension provides compliant movement between the appliance and the mechanical bond. The movement is preferably resilient or elastic movement, but may be plastic. The movement resists fracture of the adhesive by more slowly decelerating an impacting mass, reducing forces on the adhesive. A pad attached at its outer periphery to a mesh which leaves the inner central portion of the pad free may provide the compliance, so the pad exhibits flex, suspending the bracket to move with impacting masses, absorbing energy and reducing forces transmitted to the adhesive. Compliance may also be provided by coating the bracket with elastomeric material, or coating the mechanical bonding base to which adhesive bonds. Low elastic modulus adhesive or elastic bracket tie wings can also provide the compliance. Tapered appliance surfaces, particularly facing the occlusal plane, deflect impacting objects to reduce forces.

1 . An orthodontic appliance for attachment to a tooth, the appliance comprising: 
 a pad that includes an inner central portion and an outer peripheral portion contiguous with and in surrounding relation to the inner central portion;    a bracket fixed to the pad; and    bonding structure configured to provide bonding of the bracket with adhesive to a tooth, the bonding structure being compliantly attached to the pad at least at a plurality of points within the inner central portion of the pad to provide compliant movement between the bracket and the bonding structure upon impact to the bracket, so as to resist transmission of impact from the bracket to the adhesive.    
   
   
       2 . The orthodontic appliance of  claim 1  wherein the bonding structure is attached in at least one point to the outer peripheral portion of the pad.  
   
   
       3 . The orthodontic appliance of  claim 1  wherein the pad comprises a metal sheet.  
   
   
       4 . The orthodontic appliance of  claim 3  wherein the metal sheet is a foil, the bonding structure being attached in at least one point to the foil.  
   
   
       5 . The orthodontic appliance of  claim 1  wherein the pad has a plurality of regions within the inner central portion, the bonding structure being attached in at least one point to each of the plurality of regions.  
   
   
       6 . The orthodontic appliance of  claim 1  wherein the bracket is a metal bracket.  
   
   
       7 . The orthodontic appliance of  claim 6  wherein the bonding structure is a wire mesh.  
   
   
       8 . The orthodontic appliance of  claim 1  wherein the bracket comprises a material selected from the group consisting of a metal, a ceramic and a plastic.  
   
   
       9 . An orthodontic appliance for attachment to a tooth, the appliance comprising: 
 a bracket having a base, the base having thereon an outer peripheral portion and an inner central portion; and    a mesh having an attachment to the outer peripheral portion and substantially free from attachment to the inner central portion, the attachment providing compliant movement between the inner central portion and the mesh upon impact.    
   
   
       10 . The orthodontic appliance of  claim 9  wherein the bracket is formed of a material selected from the group consisting of a metal, a ceramic and a plastic.  
   
   
       11 . The orthodontic appliance of  claim 9  wherein the bracket and the mesh are each formed of metal and the attachment includes a weld joining the mesh to the base around the outer peripheral portion.  
   
   
       12 . The orthodontic appliance of  claim 9  wherein the outer peripheral portion is contiguous with the inner central portion.  
   
   
       13 . The orthodontic appliance of  claim 9  wherein the base comprises more than one region, each region having an inner central portion and an outer peripheral portion, the mesh being attached to the outer peripheral portions of more than one region.  
   
   
       14 . The orthodontic appliance of  claim 9  wherein the base includes a pad formed of a metal sheet having thereon the outer peripheral portion surrounding the inner central portion on one side of the sheet; 
 the bracket includes archwire support structure fixed to the pad on one side thereof opposite the inner central portion; and    the attachment including a weld of the mesh to the outer peripheral portion of the pad.    
   
   
       15 . The orthodontic appliance of  claim 14  wherein the pad is a foil.  
   
   
       16 . The orthodontic appliance of  claim 14  wherein the mesh is attached in a plurality of points to the outer peripheral portion of the pad.  
   
   
       17 . An orthodontic appliance for attachment to a tooth, the appliance having an external surface exposed to impact against the external surface by an external object; the appliance comprising: 
 a bracket;    a pad that includes an inner central portion and an outer peripheral portion contiguous with and in surrounding relation to the inner central portion, the bracket being fixed to and supported on the pad;    bonding structure configured to provide bonding of the bracket with adhesive to a tooth, the bonding structure being attached to the pad at least at a plurality of points within the inner central portion of the pad; and    means on the appliance for compliantly responding to impact between the tooth and the object to reduce forces between the tooth and the appliance.    
   
   
       18 . The orthodontic appliance of  claim 17  wherein: 
 the means for compliantly responding to impact includes a compliant surface layer on the appliance to serve as an interface between the appliance and the object.    
   
   
       19 . The orthodontic appliance of  claim 17  wherein: 
 the means for compliantly responding to impact includes an elastically resilient bracket.    
   
   
       20 . The orthodontic appliance of  claim 17  wherein: 
 the means for compliantly responding to impact includes an elastically resilient interface on the appliance between the bracket and the tooth.    
   
   
       21 . The orthodontic appliance of  claim 20  wherein: 
 the elastically resilient interface on the appliance includes an elastically resilient adhesive between the bonding structure and the tooth.    
   
   
       22 . The orthodontic appliance of  claim 21  wherein: 
 the adhesive between the bonding structure and the tooth has an elongation-to-failure of at least 1 percent.    
   
   
       23 . The orthodontic appliance of  claim 20  wherein the interface is between the adhesive and the external surface.  
   
   
       24 . The orthodontic appliance of  claim 20  wherein the interface is between the bonding structure and the object.  
   
   
       25 . The orthodontic appliance of  claim 20  wherein: 
 the elastically resilient interface on the appliance includes an elastically resilient interface between the bracket and the bonding structure.    
   
   
       26 . The orthodontic appliance of  claim 17  wherein: 
 the means for compliantly responding to impact includes an elastically resilient pad.    
   
   
       27 . The orthodontic appliance of  claim 17  wherein: 
 the external surface and the bonding structure are made of metal; and    the interface is between the bonding structure and the external surface.    
   
   
       28 . The orthodontic appliance of  claim 17  wherein: 
 the appliance is made of ceramic; and    the interface is between the external surface and the object.    
   
   
       29 . The orthodontic appliance of  claim 17  wherein: 
 the interface includes an elastic coating on the external surface between the external surface and the object.    
   
   
       30 . The orthodontic appliance of  claim 17  wherein: 
 the interface is between the bonding structure and the tooth.    
   
   
       31 . The orthodontic appliance of  claim 30  wherein: 
 the interface includes a resilient coating on the bonding structure between the bonding structure and adhesive that bonds the appliance to a tooth.    
   
   
       32 . The orthodontic appliance of  claim 17  wherein the interface is between the external surface and the bonding structure.  
   
   
       33 . The orthodontic appliance of  claim 32  wherein: 
 the interface includes a resilient bracket fixed to the bonding structure.    
   
   
       34 . The orthodontic appliance of  claim 17  wherein: 
 the external surface is tapered so as to deflect an impacting object.    
   
   
       35 . The orthodontic appliance of  claim 17  further comprising: 
 a protective barrier extending from the bonding structure on an occlusal edge thereof, the protective barrier being tapered so as to deflect an impacting object.    
   
   
       36 . The orthodontic appliance of  claim 17  further comprising: 
 adhesive between the bonding structure and the tooth, the adhesive having a low modulus of elasticity.    
   
   
       37 . The orthodontic appliance of  claim 17  further comprising: 
 adhesive between the bonding structure and the tooth, the adhesive having an elongation-to-failure of substantially more than 1 percent.    
   
   
       38 . A method of attaching to a tooth to resist impact, an orthodontic appliance having an external surface exposed to impact from an external object, the method comprising: 
 providing an orthodontic appliance including a bracket having bonding structure for bonding the appliance to a tooth with adhesive;    providing a resilient interface on the appliance between the tooth and the object;    providing adhesive to mechanically bond the structure to a tooth; and    mechanically bonding the bonding structure to the adhesive to attach the orthodontic appliance to the tooth.    
   
   
       39 . The method of  claim 38  wherein the resilient interface includes an elastically resilient bracket configured to resist transmission of impact from the object to the adhesive.  
   
   
       40 . The method of  claim 38  wherein the resilient interface includes an elastically resilient element between the bracket and the bonding structure configured to resist transmission of impact from the bracket to the adhesive.  
   
   
       41 . A method of constructing an impact resistant orthodontic appliance for attachment to a tooth where the appliance includes a bracket having an external surface vulnerable to impact from an external object, the method comprising: 
 providing bonding structure to the bracket for mechanical bonding of the bracket to the tooth; and    providing a compliancy on the appliance for resisting impact between the tooth and the object, the compliancy including either an adhesive of unconventionally low elastic modulus between the bonding structure and the tooth, an elastomeric coating on the bonding structure; or an elastomeric coating on an external surface of the bracket.    
   
   
       42 . The method of  claim 41  wherein the compliancy includes an elastomeric coating on the bonding structure.  
   
   
       43 . The method of  claim 41  wherein the compliancy includes an elastomeric coating on an external surface of the bracket.  
   
   
       44 . The method of  claim 41  wherein the compliancy includes an adhesive of unconventionally low elastic modulus between the bonding structure and the tooth.  
   
   
       45 . An orthodontic appliance for attachment to a tooth comprising: 
 a pad having bonding structure for bonding the appliance to a tooth with adhesive, the pad having an external surface being tapered at least along an occlusal side thereof so as to deflect an impacting object.    
   
   
       46 . The appliance of claim  49  further comprising: 
 a bracket fixed to the pad, the bracket being tapered at least on an occlusal side thereof so as to enhance deflection of an impacting object.