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The first direct bonding in orthodontia, revisited
VIEWPOINT
The first direct bonding in orthodontia, revisited David L. Mitchell, DDS, MScO Decatur, Ga.
I n the September 1990 issue of this JOURNAL an article by Cueto I stated that he had performed the first direct bonding used in dentistry. Unfortunately, the author overlooked the possibility that the literature held references to earlier instances of the use of a clinically successful adhered appliance. In 1960 the work reported in my masters thesis described such a clinically suc-
cessful adhered appliance. ~ This appliance contained several attachment modifications on or in a round hatshaped metal base that incorporated a mechanical lock for the adhesive. The mechanical lock consisted of stainless wire or tubing soldered across the innermost part of the attachment base. The attachment types were tube, channel, and edgewise (Fig. 1).
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i
Fig. 1. A, Subiect 1 with first intraoral direct-bonding attachment base after 6-month integrity trial. B, Subject 2 with tube-type attachments in place to close diastema. C, Subject 2 after completion of treatment. D, Subject 3 with channel-type bracket on upper left canine incorporated into a conventional banded appliance to extrude tooth. E, Subiect 4 with multiple channel-type brackets on upper anterior teeth with arch wire and elastics in place. F, Subject 5 with edgewise attachments on direct-bonded bases.
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188
Viewpoint
The findings contained in the bound thesis were later published in an article that detailed the construction of the appliance and the treatment of five patients? When my thesis work was done in 1959-1960, there were few in vitro studies, 47 and no known in vivo or clinically successful studies. Later, in 1965 Newman 8 described the clinical use of an adhered appliance. After consideration of the Cueto article, I felt that a concerted effort should be made to get an accurate chronology of the documented discovery and development of the adhered appliance. In the 30 years since my thesis work, I have encountered numerous people who made verbal claims concerning contributions to the development of adhered appliances, but at this time there remain few who have documented these claims. Therefore the chronology should contain only documented evidence of contributions. A report should then be made to the profession by means of a reputable source such as this JOURNAL, since few advances in orthodontics have so impacted the way we conduct our everyday practices. From a historic standpoint, determining the first contributor to conduct multidirectionally controlled tooth movements with an adhered appliance is primary in any consideration of such an accomplishment. The history of the adhered appliance certainly deserves future attention because the invention was not only highly Significant, but the obstacles to an adhered appliance were considerable. In retrospect, it is interesting to observe that Newman 9 in his later work considers many of the adverse factors encountered in the oral environment, which I had considered and discussed in my thesis. Some of these factors are the broad spans of temperature of various foods taken into the mouth (ice cream to hot coffee) that affected the adhesive bond by altering the rates of expansion and contraction of the underlying enamel surface and adhesive, the forces of mastication, and the doubts about obtaining true chemical adhesion in the presence of gross moisture. My early in vitro and in vivo trials of various polymers on smooth enamel surfaces failed when subjected to gross moisture. These trials led me to the realization that ever-present moisture in the mouth ruled out chemical adhesion alone as the only bonding force for adhered attachments, regardless of which cement one chose. If clinical success was to be achieved some other means of increasing bond strength was needed. I was aware that phosphate cements were used to attach unidirectional hooks to teeth long before I constructed bracket bases. In fact, L. B. Higley, one of my mentors, related his use of this material for attaching hooks onto impacted canines. This more than likely
Am. J_ Orthod. Dentofiw. Orthop. February 1992
influenced me to note the tenacity of some chunks of cement adhered to the teeth after a band was removed. I knew the tenacity of these chunks of phosphate cement was a function of molecular precipitation, the etching of the enamel surface, but probably a combination of both. The necessity for writing this defense today was caused by my fear in 1959 of describing what I really came to do, acid etch teeth. Regardless of our present day attitudes and cavalier use of etching, in 1959 and 1960 placing acid on teeth for the purpose of etching was unthinkable. I sincerely believed that if I had revealed what I was doing to keep the brackets on the teeth, I would not have been awarded my degree. In fact, a survey in the late seventies or early eighties by one of the commercial orthodontic companies indicated that 50% of the approximately 7,000 orthodontists did not use the adhered appliance. The main reason given was fear of acid etching the teeth. Interjecting the consideration of various cements, or the various mechanical modifications of the attachment bases is not germane to this early phase of the history of this achievement. Whether clinical success was initially accomplished with zinc phosphate cement instead of epoxy-acrylates or Eastman 910 is not relevant to the early historical development of the adhered attachment. These considerations belong to a later era of adhered appliance history. Their consideration in the early developmental era could be compared with an observer at Kitty Hawk asking one of the Wrights after the first successful powered flight, "What kind of gas did you use?" Acid etching alone made the early clinical success of adhered orthodontic appliance possible. I would never question the choice of polymers over phosphate cements today, but in 1959 phosphate cement gave this grateful investigator the cover needed to acid etch and place the earliest known adhered orthodontic appliance in patients' mouths, to that date. Although it may appear humorous today to describe phosphate cement as a bonding agent for adhered appliances, it Can be stated that all five of those patients cited in the thesis were treated to completion with that material as the adherent. Treatment on one patient lasted 14 months (Fig. 1, E). I would like to take this opportunity to state my admiration for the courteous and scholarly manner Dr. Graber has displayed in handling this matter. If, in the future others conl,~ forward with documented evidence of earlier success with an adhered orthodontic attachment, it would be a pleasure to see such evidence inserted properly into the chronology of a long neglected story of the discovery of one of our most valuable clinical orthodontic tools.
Volume 101 Number 2
Viewpoint
REFERENCES 1. Cueto, HI. A little history: the first direct bonding in orthodontia. AM J ORTHOD DENTOFACORTHOP 1990;98:276-7. 2. Mitchell DL. Bandless orthodontic attachment. [Thesis]. Chapel Hill: University of North Carolina School of Dentistry, 1960. 3. Mitchell DL. Bandless orthodontic bracket. J Am Dent Assoc 1967;74:103-10. 4. Berkson R. Dental cement: a study of adhesion. AM J OR'roOD 1950;36:701. 5. Lee H, Neville K. Epoxy resins; their applicaHons and technology. New York: McGraw-Hill, 1957.
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6. Sadler JF. A survey of some commercial adhesions;their possible application in clinical orthodontics. [Thesis]. Memphis: School of Dentistry, University of Tennessee, 1960. 7. Swanson LT, Beck JF. Factors affecting bonding to human enamel with special reference to plastic adhesives. J Am Dent Assoc 1960;61:581. 8. Newman GV. Epoxy adhesives for orthodontic attachments: progress report. AM J ORTHOD 1965;51:701. 9. Newman GV. Bonding plastic orthodontic attachments to tooth enamel. NJ State Dent J 1964;36:346-59.
AAO MEETING CALENDAR
1992--St. Louis, Mo., May 9 to 13, St. Louis Convention Center 1993--Toronto, Canada, May 15 to 19, Metropolitan Toronto Convention Center 1994--Orlando, Fla., May 1 to 4, Orange County Convention and Civic Center 1995--San Francisco, Calif., May 7 to 10, Moscone Convention Center
(International Orthodontic Congress) 1996--Denver, Colo., May 12 to 16, Colorado Convention Center 1997--Philadelphia, Pa., May 3 to 7, Philadelphia Convention Center 1998--Dallas, Texas, May 16 to 20, Dallas Convention Center 1999--San Diego, Calif., May 15 to 19, San Diego Convention Center
The first direct bonding in orthodontia, revisited David L. Mitchell, DDS, MScO Decatur, Ga.
I n the September 1990 issue of this JOURNAL an article by Cueto I stated that he had performed the first direct bonding used in dentistry. Unfortunately, the author overlooked the possibility that the literature held references to earlier instances of the use of a clinically successful adhered appliance. In 1960 the work reported in my masters thesis described such a clinically suc-
cessful adhered appliance. ~ This appliance contained several attachment modifications on or in a round hatshaped metal base that incorporated a mechanical lock for the adhesive. The mechanical lock consisted of stainless wire or tubing soldered across the innermost part of the attachment base. The attachment types were tube, channel, and edgewise (Fig. 1).
8/1/29131
i
Fig. 1. A, Subiect 1 with first intraoral direct-bonding attachment base after 6-month integrity trial. B, Subject 2 with tube-type attachments in place to close diastema. C, Subject 2 after completion of treatment. D, Subject 3 with channel-type bracket on upper left canine incorporated into a conventional banded appliance to extrude tooth. E, Subiect 4 with multiple channel-type brackets on upper anterior teeth with arch wire and elastics in place. F, Subject 5 with edgewise attachments on direct-bonded bases.
187
188
Viewpoint
The findings contained in the bound thesis were later published in an article that detailed the construction of the appliance and the treatment of five patients? When my thesis work was done in 1959-1960, there were few in vitro studies, 47 and no known in vivo or clinically successful studies. Later, in 1965 Newman 8 described the clinical use of an adhered appliance. After consideration of the Cueto article, I felt that a concerted effort should be made to get an accurate chronology of the documented discovery and development of the adhered appliance. In the 30 years since my thesis work, I have encountered numerous people who made verbal claims concerning contributions to the development of adhered appliances, but at this time there remain few who have documented these claims. Therefore the chronology should contain only documented evidence of contributions. A report should then be made to the profession by means of a reputable source such as this JOURNAL, since few advances in orthodontics have so impacted the way we conduct our everyday practices. From a historic standpoint, determining the first contributor to conduct multidirectionally controlled tooth movements with an adhered appliance is primary in any consideration of such an accomplishment. The history of the adhered appliance certainly deserves future attention because the invention was not only highly Significant, but the obstacles to an adhered appliance were considerable. In retrospect, it is interesting to observe that Newman 9 in his later work considers many of the adverse factors encountered in the oral environment, which I had considered and discussed in my thesis. Some of these factors are the broad spans of temperature of various foods taken into the mouth (ice cream to hot coffee) that affected the adhesive bond by altering the rates of expansion and contraction of the underlying enamel surface and adhesive, the forces of mastication, and the doubts about obtaining true chemical adhesion in the presence of gross moisture. My early in vitro and in vivo trials of various polymers on smooth enamel surfaces failed when subjected to gross moisture. These trials led me to the realization that ever-present moisture in the mouth ruled out chemical adhesion alone as the only bonding force for adhered attachments, regardless of which cement one chose. If clinical success was to be achieved some other means of increasing bond strength was needed. I was aware that phosphate cements were used to attach unidirectional hooks to teeth long before I constructed bracket bases. In fact, L. B. Higley, one of my mentors, related his use of this material for attaching hooks onto impacted canines. This more than likely
Am. J_ Orthod. Dentofiw. Orthop. February 1992
influenced me to note the tenacity of some chunks of cement adhered to the teeth after a band was removed. I knew the tenacity of these chunks of phosphate cement was a function of molecular precipitation, the etching of the enamel surface, but probably a combination of both. The necessity for writing this defense today was caused by my fear in 1959 of describing what I really came to do, acid etch teeth. Regardless of our present day attitudes and cavalier use of etching, in 1959 and 1960 placing acid on teeth for the purpose of etching was unthinkable. I sincerely believed that if I had revealed what I was doing to keep the brackets on the teeth, I would not have been awarded my degree. In fact, a survey in the late seventies or early eighties by one of the commercial orthodontic companies indicated that 50% of the approximately 7,000 orthodontists did not use the adhered appliance. The main reason given was fear of acid etching the teeth. Interjecting the consideration of various cements, or the various mechanical modifications of the attachment bases is not germane to this early phase of the history of this achievement. Whether clinical success was initially accomplished with zinc phosphate cement instead of epoxy-acrylates or Eastman 910 is not relevant to the early historical development of the adhered attachment. These considerations belong to a later era of adhered appliance history. Their consideration in the early developmental era could be compared with an observer at Kitty Hawk asking one of the Wrights after the first successful powered flight, "What kind of gas did you use?" Acid etching alone made the early clinical success of adhered orthodontic appliance possible. I would never question the choice of polymers over phosphate cements today, but in 1959 phosphate cement gave this grateful investigator the cover needed to acid etch and place the earliest known adhered orthodontic appliance in patients' mouths, to that date. Although it may appear humorous today to describe phosphate cement as a bonding agent for adhered appliances, it Can be stated that all five of those patients cited in the thesis were treated to completion with that material as the adherent. Treatment on one patient lasted 14 months (Fig. 1, E). I would like to take this opportunity to state my admiration for the courteous and scholarly manner Dr. Graber has displayed in handling this matter. If, in the future others conl,~ forward with documented evidence of earlier success with an adhered orthodontic attachment, it would be a pleasure to see such evidence inserted properly into the chronology of a long neglected story of the discovery of one of our most valuable clinical orthodontic tools.
Volume 101 Number 2
Viewpoint
REFERENCES 1. Cueto, HI. A little history: the first direct bonding in orthodontia. AM J ORTHOD DENTOFACORTHOP 1990;98:276-7. 2. Mitchell DL. Bandless orthodontic attachment. [Thesis]. Chapel Hill: University of North Carolina School of Dentistry, 1960. 3. Mitchell DL. Bandless orthodontic bracket. J Am Dent Assoc 1967;74:103-10. 4. Berkson R. Dental cement: a study of adhesion. AM J OR'roOD 1950;36:701. 5. Lee H, Neville K. Epoxy resins; their applicaHons and technology. New York: McGraw-Hill, 1957.
189
6. Sadler JF. A survey of some commercial adhesions;their possible application in clinical orthodontics. [Thesis]. Memphis: School of Dentistry, University of Tennessee, 1960. 7. Swanson LT, Beck JF. Factors affecting bonding to human enamel with special reference to plastic adhesives. J Am Dent Assoc 1960;61:581. 8. Newman GV. Epoxy adhesives for orthodontic attachments: progress report. AM J ORTHOD 1965;51:701. 9. Newman GV. Bonding plastic orthodontic attachments to tooth enamel. NJ State Dent J 1964;36:346-59.
AAO MEETING CALENDAR
1992--St. Louis, Mo., May 9 to 13, St. Louis Convention Center 1993--Toronto, Canada, May 15 to 19, Metropolitan Toronto Convention Center 1994--Orlando, Fla., May 1 to 4, Orange County Convention and Civic Center 1995--San Francisco, Calif., May 7 to 10, Moscone Convention Center
(International Orthodontic Congress) 1996--Denver, Colo., May 12 to 16, Colorado Convention Center 1997--Philadelphia, Pa., May 3 to 7, Philadelphia Convention Center 1998--Dallas, Texas, May 16 to 20, Dallas Convention Center 1999--San Diego, Calif., May 15 to 19, San Diego Convention Center