Design and Development of the Ultimate Ceramic Bracket

Ceramic brackets have gained widespread acceptance in orthodontic treatment due to their superior aesthetic appeal. The immediate popularity of these brackets, after their initial marketing, was tempered by their potential to damage the enamel during debonding. This paper describes the design and development of a ceramic bracket that addresses the failings of most ceramic brackets on the market today. The advancements in the design, ability to debond easily and superior bond strength make this injection-molded, low-friction bracket a truly unique choice in the field of aesthetic brackets. This white paper compares the characteristics of this bracket with other leading ceramic brackets on the market. Introduction The popularity of ceramic brackets is well documented by their rapid acceptance as aesthetic brackets of choice. While the sales of ceramic brackets are on the rise in recent years, plastic brackets have shown a marked decline. After a euphoric initial product launch, sales of ceramic brackets were almost shut down, due to catastrophic delamination of enamel during debonding. The overall sentiment in the orthodontic community was summarized by Dr. Mike Swartz as “Never before in orthodontics has so much intentional damage to enamel occurred.” Bishara writes about the necessary precautions when debonding some brackets that have to be shattered in the mouth. He also writes about the greater susceptibility to cracking with machined ceramic brackets that have micro-cracks on the surface. In the mid 1990’s two orthodontic companies relaunched ceramic brackets with engineered bases to assure safe debonds. One was the MXi bracket from TP Orthodontics and the other was Clarity, from Unitek. Ceramic brackets in the market today are listed in Table I. Deva Devanathan is the Vice President of Research and Development at TP Orthodontics, Inc. He holds a M.S. Degree in Chemical Engineering from the University of Connecticut and a M.S. Degree in Biomedical Engineering from the University of Texas. Mr. Devanathan has over 21 years of experience in the development and testing of biomedical polymers and processes. He holds several patents. The MXi bracket incorporates an integral polymer mesh base, which guarantees excellent bonding and also safe debonding. While the MXi brackets have demonstrated superior clinical performance, a new series of ceramic brackets called InVu has been introduced with significant improvements in product design, low friction, bonding and also reliable and safe debonding characteristics. Design Rationale The InVu ceramic bracket has been designed to optimize various key design parameters, such as: • Profile height (offers the lowest). • Low friction (comparable to metal brackets). • Ease of debonding (debonds just like metal brackets). • Good bond strength (only ceramic bracket offering a mesh base). • Smooth radii on all edges to prevent archwire binding and cutting of elastomerics. True Twin Bracket Design InVu incorporates a true twin bracket design (Figure 1). It TABLE I. Ceramic Brackets Bracket Name Manufacturer MXi TP Orthodontics InVu TP Orthodontics Clarity Unitek Signature III RMO Luxi II RMO Virage American Orthodontics Mystique GAC Inspire Ormco Figure 1. InVu – Twin bracket design A B