a fo P vw? b Ronald E. Goldstein, DDS 8 David A. Garber, DMDComplete Dental Bleaching Ronald E. Goldstein, DDS David A. Garber, BDS, DMD Clinical Professor of Oral Rehabilitation Clinical Professor of Periodontics ‘School of Dentistry School of Dentistry Medical College of Georgia Medical College of Georgia Augusta, Georgia Augusta, Georgia Adjunct Clinical Professor of Prosthodontics Clinical Professor of Oral Rehabilitation Goldman School of Graduate Dentistry School of Dentistry Boston University Medical College of Georgia Boston, Massachusetts Augusta, Georgia Visiting Professor of Oral and Maxillofacial Imaging and Continuing Education School of Dentistry University of Southern California Los Angeles, California Adjunct Professor of Restorative Dentistry University of Texas Health Science Center San Antonio, Texas qd Quintessence Publishing Co, Inc ‘becks Chicago, Berlin, London, Tokyo, Sio Paulo, Moscow, Prague, WarsawLibrary of Congre Goldstein, Ronald E. Complete dental bleaching/Ronald E, Goldstein, David A. Garber. p.m, Includes bibliographical references and index. ISBN 0-86715-290-7 1. Teeth—Bleaching, |. Garber, David A. I. Title [DNLM: 1. Tooth Bleaching, 2. Tooth Discoloration—therapy. WU 166 G624e 1995) RK320.B55065 1995 617,6°34—de20 DNLM/DL for Library of Congress 95-14260 cP @6 queteence ‘oaks © 1995 by Quintessence Publishing Ga, Ine All rights reserved. This book or any part therein may not be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of the publisher. Editor: Adam Haus Designer: Jennifer Sabella Printed by Everbest Printing, Hong KongContents Bleaching: A New Role for Restorative Dentistry 1 The Chemistry of Bleaching 25 Howard Frysh, BDS, DDS Diagnosis and Treatment Planning 35 In-Office Bleaching of Vital Teeth 57 Nightguard Vital Bleaching 71 Harald O. Heymann, DDS, MEd & Van B. Haywood, DMD Bleaching Pulpless Teeth 101 David R. Steiner, DDS, MSD & John D. West, DDS, MSD Total Team Care in Combination Bleaching 137 Index 161Contributors Howard Frysh, BDS, DDS ciate Professor College of Dentistry Baylor University Dallas, Texas Van B. Haywood, DMD Associate Professor Department of Oral Rehabilitation School of Dentistry Medical College of Georgia Augusta, Georgia Harald O. Heymann, DDS, MEd Chair, Department of Operative Dentistry School of Dentistry University of North Carolina Charlotte, North Carolina R. Steiner, DDS, MSD. Clinical Associate Professor Department of Endodontics School of Dentistry University of Was! Seattle, Washington gton John D. West, DDS, MSD Clinical Associate Professor Department of Endodontics School of Dentistry University of Washington Seattle, WashingtonPreface Few dental treatments have been more successful in the past decade than bleaching teeth. Both in-office and at-home treat- ments have captured the attention of the lay public throughout the world, People can now have more control than ever over the appearance and coloration of their teeth and, in most cases, even play a role in obtaining their desired result. Since 1976, when the first chapter on tooth bleaching appeared in an esthetic dentistry textbook (Goldstein, Esthetics in Dentistry), techniques and results have improved dramatically. Not only has the public embraced the concept, but dentists have integrated it as a routine, rapid, and conservative part of their esthetic armamentarium. ‘This text shows just how much the science of tooth bleaching has become part of the esthetic dental arena. Dr Howard Frysh’s chapter on the chemistry of bleaching provides the scientific information as to how and why tooth bleaching is so effective. Drs Haywood and Heymann complement the in-office bleaching chapter with detailed attention to nightguard vital bleaching, just as Drs Steiner and West provide an important new look at bleaching the pulpless tooth. The final chapter integrates all of the various esthetic dental modalities and demonstrates how bleaching can be an integral part of most interdisciplinary treat- ment plans. We hope that this book will encourage appropriate use of bleaching in your practice of esthetic dentistry.Acknowledgments No text we write would be complete without the constant help we receive from our office secretaries, Margie Smith, Cynthia Clement, and Candace Paetzhold. The administrative and research assistance of Susan Hodgson, coupled with her writing skills, improved the final version of the text. ‘We would like to acknowledge the technical photographic advice and help received from Mr Howard Golden and Mr John Johnny of the Minolta Corporation. Most of the photographs and slides were made using the Minolta 7000 or 7XI with a 100- mm macro lens and the 1200 AF electronic flash unit. Most of the combined-therapy cases were the work of our mas- ter ceramist, Pinhas Adar, an integral part of our esthetic team. Finally, we are ever mindful of the tremendous sacrifice our families make in allowing us to take extra time away from them to be able to produce a text such as this one. So, to Judy, Barbara, Karen, Jennifer, and Michael we say thank you for all your love and support.A New Role for Restorative Dentistry Does Bleaching Belong in My Practice? The last three decades have witnessed immense changes in den- tistry, beginning with the profession's dramatic and unprecedent- ed success in the reduction of caries and periodontal disease. The subsequent decline in what had been the primary activities in dentistry caused many dentists to reexamine and redefine their roles in meeting the dental needs of their patients. Perhaps the single most significant change was contemporary dentistry’s new emphasis on esthetics. This was a direct result of dentists’ ability to bond predictably to teeth, allowing patients to keep sound tooth structure while improving their looks. Attractive teeth have always been the typical patient's primary concern. In the past, dentists were often dismayed by a patient's disappointment in a “perfect restoration,” painstakingly crafied of the finest gold or other material, with minimized enamel reduction and long-lasting preservation of function. ‘The patient, of course, had hoped the restoration would mimic the appear- ance of the original teeth. Today, by taking full advantage of new materials and techniques, dentists can often meet or even exceed such expectations2 Chapter | ‘A New Role for Restorative Dentistry What most people really want, however, are teeth that make them look younger, healthier, and more attractive. Thirty years ago, patients considered dentists both allies in the prevention of, dental problems and friendly repair professionals when such problems inevitably occurred. Today, dentists are increasingly becoming the professionals to whom people tum first for advice and assistance on improving their appearance. The increase of adult orthodontics is one measure of this trend, The sharp rise in the acceptance and demand for treatments of otherwise healthy teeth to make them brighter and whiter is an even better measure. Bleaching is now the single most common esthetic treatment for adults, We estimate that more than a million people have had teeth bleached by dentists, while perhaps millions more have tried their own hand at bleaching with over-the-counter products. ‘The popularity of bleaching is easily understood. For the appropriate patient, with careful diagnosis, case selection, treatment plan- ning, and attention to technique, bleaching is the simplest, least invasive, least expensive means available to lighten discolored teeth and diminish or eliminate many stains in both vital and pulpless teeth. Once considered the province of a few pioneering specialists in esthetic dentistry, bleaching has now moved into the mainstream of restorative dentistry. A growing number of your patients are probably asking you what bleaching can do for them now. The question is no longer whether or not to add. bleaching to your practice. To provide the services increasingly. expected by your patients and provided by your colleagues, you have to provide bleaching. But bleaching is not a simple yes-or-no treatment option, espe- cially as a larger number and wider range of patients expect and ask for brighter teeth. Patients interested in bleaching range from children to senior citizens; from the well-to-do to those who must keep costs at the bare minimum; from the person with a single deeply discolored pulpless tooth to one with a smile yellowed by years of staining, various diseases, systemic medication intake, or simply aging. More significantly, some patients’ only problem isWhat Are the Major Causes of Discoloration? 3 tooth discoloration, while others have periodontal problems, tooth malalignment, and caries requiring preliminary attention, For a few patients, one or two in-office bleaching sessions will produce results that seem almost miraculous. For a few patients—and it’s essential to recognize which few—bleaching may never be a safe or appropriate therapy. But for the majority of patients seeking more attractive smiles, bleaching holds out a varying amount of promise for improvement, especially when used as an adjunct to other cosmetic procedures. In combination with other esthetic procedures, such as microabrasion, lightening a stained tooth before veneering, or crowning to improve the color of adjacent teeth, bleaching expands the scope of esthetic dentistry, In the 1980s and 1990s, new partnerships and referral patterns have given bleaching a new role as an adjunct to ortho- dontics, orthognathic surgery, endodomtics, and restorative den- tal treatments, as well as to treat- ments in dermatology, plastic and reconstructive surgery, and other fields. In fact, an increasing number of dentists and other health professionals concerned with esthetics are asking all patients if they are satisfied with the color of their teeth. The appropriate questions for today’s dentist, therefore, are how best to incorporate various methods and materials of bleaching into total treatment plans and how best to work with a team of dental and other professionals to achieve the patient's objectives, These are the primary questions this book is designed to answer. What Are the Major Causes of Discoloration? Superficial Changes Affecting Only the Enamel Surface ‘These usually are caused by habitual use of highly colored foods or beverages such as tea, coffee, and cola, all of which can cause4 Chapter | A New Role for Restorative Dentistry tenacious brown to black discolorations. Nicotine is another cause of dark surface stains. Smoking tobacco cigarettes, cigars, or pipes produces a yellowish brown to black discoloration, usually in the cervical portion of the teeth and primarily on the lingual surfaces, while smoking marijuana may produce sharply delin- eated rings around the cervical portion of the teeth adjacent to the gingival margins. Chewing tobacco frequently penetrates microcracks in the enamel to produce an even darker stain, in addition to the soft tissue problems often found in users. All of these surface stains are highly amenable to bleaching, although ficult to remove from pits, fissures, grooves, or enamel defects, If microcracks have allowed the stain to permeate the tooth, bleaching may not be as appropriate or effective as some of the newer conservative restorative treatments (Figs 1-La and 1-1b) stains are more Discoloration of the Tooth Structure Teeth can become stained and discolored, sometimes before they even erupt (Figs 1-2a and 1-2b), when the tooth structure itself is altered by a discoloring agent. This happens in a variety of ways: Medication Given Systemically, Especially During Tooth Formation Dentists first recognized the devastating effect some medications could have on tooth formation in the late 1950s, when large numbers of young people began displaying yellow, brown, or gray stains caused by the antibiotic tetracycline.! The first certain identification was reported in a study of cystic fibrosis patients, for whom tetracycline was (and unfortunately remains) one of the most effective treatments for control of secondary infection of the respiratory system. The severity of the stains and specific color depend on the type of tetracycline administered (more than 2,000 variants have been patented), the duration of use, and the stage of tooth formation at the time of use. In fact, tetracycline provided dentists much insight into the mechanism by which medications could result in intrinsic stains. Teeth are most susceptible to tetracycline discoloration during formation, beginning with the second trimester in utero andWhat Are the Major Causes of Discoloration? 5 Card ica Fig I-la This patient’s habit of smoking several Fig |-Ib Although the teeth were bleached and packs of cigarettes per day stained the teeth, makin, the patient's smoking habit was reversed, a ceramic the microcracks even more prominent,as typified in _ alternative was chosen to improve the left central the lefe central incisor. incisor. Fig 1-2a High fever or certain medications can Fig 1-2b A combination of in-office and matrix cause Individual tooth defects or tooth discolor- home bleaching was successful not only in eliminat- ation, depending upon occurrence or administra- ing the stain but also in lightening the patient's teeth, tion, Note dark staining on two-thirds of the labial surface of this patient’s central incisors.& Chopter |__A New Role for Restorative Dentistry continuing to about 8 years of age. It is believed that the tetracy- cline particles are incorporated into the dentin during calcifica- tion of the teeth, probably through chelation with calcium, which forms tetracycline orthophosphate.” The discoloration itself results from exposure of these tetracycline-affected teeth to sunlight, which is why the labial surfaces of the incisors tend to darken more quickly to gray or brown while the molars remain yellow for a longer time. In 1970, Cohen and Parkins’ first published a method for bleaching the discolored dentin of young adults who had under- gone tetracycline treatment for cystic fibrosis. The results were good, especially in cases with lighter staining and without the banding seen in category III as proposed by Jordan and Boks- man.‘ Bleaching improved the appearance and no doubt the lives of many of this tetracycline-affected generation; the results also encouraged dentists to begin applying bleaching procedures to other stains and discolorations. ‘Tetracycline is still used, especially for Rocky Mountain spotted fever, chronic bronchitis, and cystic fibrosis, but the Food and Drug Administration has warned for more than 30 years about its use for pregnant women or children when not absolutely necessary. A condition you may see increasingly in your practice is minocycline staining in adolescents and adults whose teeth had already formed when they used this antibiotic, sometimes for very short periods. This semisynthetic derivative of tetracycline is used routinely for severe acne and a variety of systemic infec- tions. Unlike tetracycline, which can be used in adults without risk of discoloration, minocycline appears to be absorbed from the gastrointestinal tract, where it chelates with iron, forming insoluble complexes. Chung and Bowles? performed a series of absorbance spectrum studies in vitro that provided evidence for oxidative dissemination in minocycline leading to intrinsic den- tal staining. Another study by Dodson and Bowles® suggests the minocycline pigment produced in tissues is the same as or very imilar to that produced by ultraviolet radiation, Some minocy- cline stains may be responsive to bleaching (Figs 1-3a and 1-3b), while others with severe banding may require porcelain laminate veneers for a satisfactory result.What Are the Mojor Causes of Discoloration? 7 Fig I-3a This woman presented with mild minocy- Fig I-3b Bleaching eliminated much of the staining cline stains. and produced a pleasing result to the patient. Excessive Intake of Fluoride During Enamel Formation and Calcification, Resulting in Discoloration and Surface Defects Black and McKay presented the first clinical description of fluore- sis in 1916,” although the role of fluoride in causing these defects was not discovered for another 15 years, In areas where drinking water has a fluoride content in excess of four parts per million, most frequently in the southwestern United States,* a majority of children exposed for extensive periods between the third month of gestation and 8 years of age will develop moderate to severe discoloration of the tooth surface. Drinking water with a fluoride content in excess of 1 to 2 ppm. can cause metabolic alteration in the ameloblasts in young chil- dren, resulting in a defective matrix and improper calcification. Use of fluoridated products, such as dentifrice, mouthwash, and vitamins, may increase this problem in areas where the fluoride concentration is close to this range.’ The type and degree of fluo- rosis problems depend on genetic vulnerability, the point of development of the enamel at which excessive fluoride intake occurs, and the intensity and length of exposure, Histologic8 Chapter | A New Role for Restorative Dentistry examination of the affected teeth will show a hypomineralized, porous subsurface enamel and a well-mineralized surface layer. This enamel hypoplasia is termed endemic enamel fluorosis or “mottled enamel.” ‘The premolar teeth are the most commonly affected, followed by second molars, maxillary incisors, canines and first molars, and mandibular incisors. Where fluoride cor centration is very high, primary teeth may also be affected Affected teeth usually have glazed surfaces and may be paper white, with areas of yellow, brown, or even black shading in any location on the teeth, Stains may range from a simple brown dif- fuse pigmentation on a smooth enamel surface (Figs 1-4a and 1- 4b) to opaque fluorosis, with flat gray or white flecks or larger white or opaque spots visible on the enamel surface. Bleaching can be an effective treatment modality for this type of discoloration, If the mottling is serious enough, the enamel may be chalky, without the glaze and luster of a normal tooth. If staining is accompanied by pitting and other surface defects, bleaching is best viewed as a useful adjunctive treatment preced- ing bonding or veneering, If fluorosis has caused severe loss of enamel, bleaching should not be used at all iad 4a Fluorosis is the cause of this brown pig- Fig 1-4b Individual in-office tooth bleaching was mentation, effective in eliminating the stain and producing a more pleasing smile.What Are the Major Causes of Discoloration? 9 Stain From Systemic Conditions Although there are a number of genetic conditions or childhood illnesses that cause discoloration of the teeth, most are rare and infrequently seen, However, for those conditions in which discol- oration results from a pigment infusion of the dentin during development, bleaching can be quite effective. These conditions include the bluish-green or brown primary teeth that result from postnatal dentin staining by bilirubin in children who suf- fered severe jaundice as infants; the characteristically brownish teeth caused by destruction of an. excessive number of blood-cell erythrocytes in erythroblastosis fetalis, a result of Rh-factor incompatibility between mother and fetus; and the purplish- brown teeth of persons with porphyria, a rare condition that causes an excess production of pigment, Bleaching is usually a less appropriate treatment than bonding or crowning when illness has caused discoloration of the teeth by interfering with the normal matrix formation or calcification of the enamel, Hypoplasia or hypocalcification can occur with genetic conditions like amelogenesis imperfecta and clefting of the lip and palate or with acquired illnesses such as cerebral palsy, serious renal damage, and severe allergies. Brain, neurolog- ical, and other traumatic injuries also can interfere with the nor- mal development of the enamel. Deficiencies of vitamins C and D and of calcium and phosphorous during enamel's formative period can cause hypoplasia Stain From Dental Conditions or Treatments Dental caries are a primary cause of pigmentation, appearing as either an opaque white halo or a gray cast. An even deeper brown, to black discoloration can result from bacterial degradation of food debris in areas of tooth decay. ‘Tooth-colored restorations such as acrylics, glass ionomers, or composites can cause teeth to look grayer and discolored as the restoration ages and degrades10 Chapter I A New Role for Restorative Dentistry (Figs 1-5a and 1-5b). Metal restorations, even silver amalgams and gold inlays, can reflect discoloration through the enamel, a prob- Jem that may become more evident with the thinning and translu- cency of enamel that occurs with aging (Fig 1-6). Bleaching may not be necessary once the proper repair or replacement of these restorations takes place. A more difficult discoloration occurs when oils, iodines, nitrates, root-canal sealers, pins, and other materials used in dental restora tion have penetrated the dentinal tubules. The length of time the substance has penetrated the tubules will determine the amount of residual discoloration and, consequently, the success of bleaching. Tooth Color Changes Due to Aging ‘anges in tooth color, as well as tooth form and texture, almost inevitably accompany aging. Most newly formed teeth have thick, even enamel which modifies the base color of the underlying dentin.” That bright, milky white appearance seems to be the ideal in today’s society. Unfortunately, all of the numerous genetic, envi- ronmental, medical, and dental causes described above move teeth further away from that ideal, and aging intensifies all of their effects Food and drink have a cumulative staining effect, and these and other stains become even more visible in the older patient because of the inevitable cracking and other changes on the enamel surface of the tooth, within its crystalline structure, and in the underlying dentin. Furthermore, amalgams and other restorations placed years ago inevitably degrade over time, causing further staining, ‘Were these environmental assaults not problem enough, aging usually brings a thinning of the enamel, which may cause the facial surface of the tooth to appear flat with a progressive shift in color due to a loss of the translucent enamel layer. At the same time as the enamel begins to thin, secondary dentin formation, a natural tooth protective mechanism in the dentin and pulp, further exacerbates the problem. The combination of less enamel and more darkened, opaque dentin creates an older-looking tooth. Unless the enamel is very badly worn, however, bleaching can be an effective treatment for many of the discolorations seen in older patients, As Chapter 3 explains, bleaching is particularly appealing for many patients because of the minimal chair time, expense, and potential for post- operative sensitivity due to recession of the pulp (Figs 1-7a and 1-7b)What Are the Major Causes of Discoloration? 11 roa Fig |-5a Discolored com- posites accentuated unat- tractive yellowed teeth, Fig I-5b Bleaching light- ened the teeth but did not change the color of the restorations. Fig 1-6 This patient wanted a lighter look to her smile and objected to the discoloration ‘caused by her old amalgams in the premolar area. Bleaching alone has improved this stain; however total resolution will only be accom- plished by replacement of the old amalgams.12. Chapter | A New Role for Restorative Dentistry ae Ta These discolored teeth are a sign of an 1-7 Teeth yellowed due to age can be excel- aging smile. Bleaching could help provide a more lent candidates for both in-office or matrix bleaching youthful look, Bleaching: An Evolving History Bleaching is not new! The earliest efforts to lighten teeth through bleaching took place more than a century ago, with bleaching, agents painted directly on the tooth surface or packed inside a nonvital tooth. The earliest agent reportedly used was oxalic acid, described by Chappel in 1877." Following experiments with var- ious forms of chlorine, Harlan described in 1884 what is believed to be the first use of hydrogen peroxide, which he called hydrogen dioxide." Although many of the mechanisms by which bleaching removes discoloration are not yet fully understood (see Chapter 2 for an explanation of bleaching chemistry), the basic process in- volves oxidation, in which the bleaching agent enters the enamel/ dentin of the discolored tooth and releases the molecules contain- ing the discoloration. How well it works depends upon the cause of the stain; where, how deeply, and how long the stain has per- meated the structure of the tooth; and how well the bleachingBleaching: An Evolving History 13 agent can permeate to the source of the discoloration and remain there long enough to release deep stains. If the stains are on the surface or subsurface of the tooth, the process is fairly simple. The addition of mild etching to remove surface organic material appears to enhance this process by cleaning the teeth and perhaps by exposing slightly deeper areas of enamel to the bleach. But hydrogen peroxide alone can permeate through the surface of the tooth to reach stained enamel and dentin and release discol- oration that has penetrated the tooth’s inner structure Once hydrogen peroxide was established as the most effective bleaching agent, dentists tuned their attention to finding ways to facilitate its absorption and penetration to speed the oxidation process, Early efforts included use of electric current and ultravio- let light." In 1918, Abbot discovered what remains the basic combination used today: a high-intensity light that produces a rapid rise in the temperature of the hydrogen peroxide to acceler- ate the chemical process of bleaching." Since then, the history of bleaching has been one of continuous improvement in the effec- tiveness and ease of use of bleaching agents, heat and light cata- lyst devices, and alternative methods, the most contemporary of which are described throughout this book. Bleaching nonvital or pulpless teeth changed less rapidly. The first reported instance of bleaching nonvital teeth was in 1895, when a dentist named Garretson applied chloride to the tooth surface, The results were not inspiring, and there were few follow- ers, But in 1958 Pearson realized the dentist could take advantage of the nonvital tooth’s lack of a pulp. He packed the same hydro- gen peroxide agent being used for bleaching of vital teeth, Super- oxol, in the pulp chamber for 3 days." By the late 1960s the stan- dard method was established by Nutting and Poe, who sealed a mixture of 30% hydrogen peroxide and sodium perborate in the pulp chamber for up to a week." Chapter 6 describes in detail the continuing improvements in bleaching of the nonvital tooth, More recently, we have seen introduction of an alternative method to facilitate absorption of the bleaching agent by apply- ing a weaker bleaching solution to the teeth for longer periods, usually by placing it in a retainer-like matrix worn by the patient for extended periods. Chapter 5 covers the rationale, indications, and step-by-step methodology for this immensely popular approach to whiter teeth.14 Chapter | ‘A New Role for Restorative Dentistry Hislam.net Problem Bleaching is now moving into a new phase of development. In its first phase at the turn of the century, bleaching teeth was a rather provocative, experimental modality. In its second phase, despite the fact that dentists recognized its effect ty in the middle of this century, bleaching was usually seen as a last-ditch effort to correct a particularly disfiguring discoloration, performed on highly selected patients by a few pioneering den- tists interested in esthetic dentistry. Most general dentists used more familiar restora restorative materials then available. Their hesitancy began to change somewhat in the 1970s with the dramatic results obtained for thousands of children with tetracycline staining or with surface discolorations from fluorosis. In its third phase, bleaching became more acceptable as an effective and safe in- office treatment for a wider spectrum of cases, but it still seemed to remain the province of the specialist and relatively few general dentists. Today, in the fourth and doubtless not yet the final stage, in-office and matrix bleaching are household words, and. most dentists consider themselves esthetic dentists, The develop- ment of accessible computer imaging for the dental practice con- tinues to enhance patient understanding, expectation, and satis- faction with innovative esthetic techniques and further improves the collaborations between dental and other specialists involved in esthetic enhancements. eness and safe- e methods, such as crowns and the newer ‘Throughout this evolution, there have been two consistent questions in the research that accompanied clinical development: 1. How well does bleaching work? ‘As presented in this chapter, the efficacy of bleaching depends on many factors, ranging from the type of stain, through the condition of teeth, to patient compliance during and following treatment. Goldstein? and Jordan and Boksman‘ estimate that vital bleaching is effective in as many as three-fourths of selected cases. There is also concern with long- term effectiveness, since for most patients there is an immediate loss of the bleaching effect in the first weeks following treatment and virtually all patients need retreatment within 3 years for a continuing optimal effect. Chapter 7 describes this work in more detail 2. How safe is it? The use of any of the current bleaching agents is not totally without risk, and care must be taken in their storage, application, and monitoring.Bleaching: An Evolving History 15 As will be shown, protecting the eyes, skin, and soft tissue of the patient (as well as the dental team) from potential damaging effects of either heat, light, or the bleaching agent itself has always been an essential part of the in-office treatment process. The lack of anesthesia during in-office bleaching assures that any microscopic leak in the rubber dam would be noticed and corrected immediately. Most of the earlier studies of in-office bleaching during the late 1970s and 1980s focused on possible deleterious damage to the pulp in vital teeth. It has been known for more than 40 years that substances can penetrate through enamel and dentin into the pulp. The low molecular weight of hydrogen peroxide and its capability to denature proteins probably enhances its ability to penetrate teeth. Numerous studies of canine, bovine, and human teeth have looked at various solutions of hydrogen perox- ide, heat applications, and combinations of the two in potential damage.!2:!54 The earliest results were positive but cautionary, demonstrating that a technique of low heat application of approximately 98° to 140°F, using a 30% to 35% hydrogen per- oxide solution, can sometimes cause some low-grade reversible pulpal inflammation and possi- ble hard tooth structure damage. ‘These findings have encouraged the establishment of current pro- tocols involving shorter bleach time and restricted heat use. As Sakaguchi and Hampel point out,2 there have been only a few reports of side-effects resulting from bleaching therapy of vital teeth. These included mild inflammatory responses in teeth. treated with heat and hydrogen peroxide, while the controlled use of saline and heat or hydrogen peroxide without heat did not cause a significant number of inflammatory responses.” Safety issues may be more pressing when bleaching pulpless teeth, Although bleaching of pulpless teeth offers the most dra- matic changes in appearance, it offers the greatest potential haz~ ard; . .. cervical resorption of the tooth.2 Chapter 6 describes the choices of technique, placement of the bleaching agent within the tooth, and bleaching materials that can make this as safe as most other commonly used dental treatments. Finally, the rapid increase in home bleaching has caused an increased concern for safety, Chapter 5 describes the current find-16 Chapter |_A New Role for Restorative Dentistry ings in more detail, but reports suggest that, in general, the short- term safety and efficiency for hydrogen peroxide systems appear high.2® Lower concentrations of hydrogen peroxide have been found to be less likely to cause oral irritation, Advantages of Bleaching Used Alone For most patients, the preeminent advantage of bleaching is its relatively low cost. A second advantage that leads many patients to inquire about bleaching is the fact that no tooth structure is reduced to achieve tooth whitening, A third major advantage of using bleaching to acquire lighter teeth is the fact there is no need for continuous replacement, as with restorative alternatives. Furthermore, there will be no chipping or fracturing of the nat- ural bleached teeth, as tends to occur with restorative modalities (especially bonding, but also with laminating or crowning) Many patients also appreciate the minimal office time made pos- sible by combining an initial in-office procedure (which pro- ( duces immediately gratifying improvement in lightness) with dentist-monitored home bleaching as described in Chapter 4. For most dentists, bleaching’s chief advantage is its minimal invasiveness, which requires no alteration of tooth structure or loss of enamel yet produces the desired improvement in appear- ance (Figs 1-8a and 1-8b)Advantages of Bleaching Used Alone 17 before Fig I-8a The most conservative treatment for patients who desire whiter teeth can begin with bleaching Pree Fig |-8b Discolored teeth can often be remedied by bleaching alone.18 Chapter | A New Role for Restorative Dentistry Disadvantages of Bleaching Used Alone First, the effect of bleaching on natural teeth is not permanent, compared to crowns and veneers, which can be restored to their original brightness through cleaning, This is particularly significant when the staining is caused by behaviors the patient is unwilling to give up, such as smoking or drinking coffee and tea. Second, it requires more than one or two sessions, Compared to bonding, for instance, the average patient may need to return for several sessions of in-office bleaching, Third, it is not effective for all forms of discoloration, such as the banding seen in severe tetracycline staining (Fig 1-9a). The band- ing effect will remain, albeit somewhat lighter in color. However, depending on both lip line and amount of tooth structure revealed during smiling, bleaching can sometimes serve as a compromise treatment (Fig 1-9b). Bleaching also cannot totally correct opacity ‘or white spots frequently seen in fluorosis, While the white areas may be less noticeable on a brightened tooth, they can be hidden completely only by removal or some type of restorative endeavor, Furthermore, bleaching cannot alter the shape or form or position ofa tooth, as can be done with bonding, laminating, or crowns. Fourth, bleaching is inappropriate and even dangerous for some problems. For example, bleaching is contraindicated when the sur- face, thickness, and health of the enamel has been compromised for any reason, ranging from microcracks that have allowed the stain to permeate the tooth or thinned enamel seen in many sys- temic diseases or in some older persons. Fifth, bleaching can be somewhat unpredictable and change “the balance of the smile.” If the patient has noticeable amalgams in the area to be bleached, for example, these will have to be removed, since the color difference would be even more apparent after bleaching, necessitating amalgam replacement (see Fig 1-6) Many of these disadvantages, except for those involving dam- aged enamel, apply only to bleaching used alone. While they are not necessarily contraindications, they are indicators that bleach- ing serves best as an adjunct to other esthetic dental treatments. Chapters 3 and 7 explain in detail how this works and where bleaching belongs in the sequence of treatmentDisadvantoges of Bleaching Used Alone 19 nie Fig 1-9a This 31-year-old man has severe Class 3 tetracycline staining, Whereas normal bleaching treatments could not achieve the tooth color most people would desire, this patient wanted to try the more conservative treatment first. 9 Three in-office treatments plus matrix (home) treatments accom- plished the resule seen here. Because his normal smile line masked most of the problem, the patient was pleased with bleaching therapy alone.20° Chapter 1A New Role for Restorative Dentistry Advantages of Incorporating Bleaching into Combined Therapy First, adding bleaching to a long-term treatment plan provides immediate improvement in the smile for patients going through other treatments such as orthodontics, periodontics, or implants, and waiting for the final restorative phase incorporating perma- nent treatments such as porcelain laminates or crowns Second, bleaching improves the effect of combined treatment ina variety of ways. For example, lighter shades of crowning or veneering can be used after bleaching other teeth in the arch, then matching this lighter shade. Bleaching all but a single com- promised tooth, which can instead be bonded, maximizes effect and minimizes office time and patient expense. Disadvantages of Incorporating Bleaching into Broader Treatment Plans ‘These are few. For the patient, adding other treatments generally adds to the office time and cost required. For the dentist, a com- bination of approaches requires more extensive planning and careful attention to the complexities of matching colors. This is especially important when using bleaching, since the final result is not evident while the patient is in the operatory chair for in- office bleaching and is not completely under the dentist's control when matrix bleaching is used. Chapters 3 and 4 address these problems. Other obstacles include: * Increased cost in equipment and office time and training, In spite of increasingly sophisticated heat-light instrumenta- tion, bleaching requires a team approach for maximum effectiveness and safety. ¢ The lack of complete predictability, which means the effec- tiveness of bleaching in any specific patient will depend on individual variables. Some of these cannot be determined precisely, such as the cause of the stain and where, how deeply, or how long the stain has permeated the structure of the tooth. The resulting variable degree of improvement isGreating 0 Dental Team to Help Shape and Meet Increased Patient Expectations 21 not so significant when bleaching is used alone, but is important when trying to match restorations or other dental treatment, which can be complicated. © The relative impermanence of bleaching, When used in con- junction with more long-lasting treatments, suich as bond- ing, periodic rebleaching of the natural teeth to retain a color match will be an ongoing need. Creating a Dental Team to Help Shape and Meet Increased Patient Expectations Bleaching is an appropriate adjunct to cosmetic contouring, orthodontics (especially in the 25% of all orthodontic patients who are adults), periodontal surgery (particularly when used for esthetic reasons such as correcting loss of interdental space or high lip line), orthognathic surgery, and plastic and reconstruc- tive surgery. One of the unexpected advantages of using bleach- ing with these procedures is that it creates new communication, understanding, and referral patterns between many different spe- cialists. We are beginning to see the dentist become the initial health- care provider to whom people bring their wishes, sometimes expressed quite tentatively, for a more attractive appearance. ‘Thanks to innovative materials and technology in dentistry, including increasingly sophisticated computer systems, you can be the person who advises your patient on the multitude of pos- sibilities. You can be the professional who assembles the dental, medical, and sometimes other professionals to achieve the patient’s desires, You can appropriately involve and refer to col- leagues in related specialties such as periodontics, orthognathic surgery, plastic and reconstructive surgery, and dermatology, as ‘well as other areas concerned with appearance. You will let these specialists know how your esthetic skills can enhance the appear- ance of their patients seeking specialty care.22 Chapter |_A New Role for Restorative Dentistry References 10, u 12, 13 15. 16. . Arens D. The rold of bleaching in esthetics. Dent Clin North Am, 1989;33:319. Mello HS. The mechanism of tetracycline staining in primary and permanent teeth, J Dent Child 1967;34:478 Cohen S, Parkins FM. Bleaching tetracycli Oral Surg 1970;29:465-471 Jordan RE, Boksman L, Conservative vital bleaching treatment of discolored dentition. Compend Contin Ed Dent 1984;5(10):803-808. Chung HY, Bowles WH. Oxidative changes in minocycline leading to intrinsic dental staining, | Dent Res 1989;68 (special issue):413 Dodson DL, Bowles WII, Production of minocycline pigment by tissue extracts. J Dent Res 1991;70:424. Black GV, McKay FS, Mottled teeth: An endemic devlopmental imperfection of the enamel of the teeth heretofore unkown in the literature of dentistry. Dent Cosmos 1916;58:129. ‘Murtin JR, Barkmeier WW. Chemical treatment of endemic dental fluorosis, Quintessence Int 1982;13;363-369. Goldstein RE. Bleaching teeth: New materials, new role. J Am Dent Assoc 1987: Dec(special issue):44E-52E. Dzierack J. Factors which cause tooth color changes: Protocol for in-office “power bleaching.” Pract Periodont Aesthet Dent 1991;3(2):15~20. Zaragoza VMT. Bleaching of vital teeth: technique. FstoModeo 1984;9:7-30. Zack 1, Cohen G. Pulp response to externally applied heat. Oral Surg 1965;19:515-530. Pearson H. Bleaching of the discolored pulpless tooth. J Am Dent Assoc 1958;56:64-68, ined vital teeth. er . Nutting EB, Poe GS. A new combination for bleaching teeth. Dent Clin North Am 1976;10:655-662 Baumgartner JC, Reid DE, Pickett A. Human pulpal reaction to the modified Mcinnes bleaching technique. | Endodont 1983;9:527-529. Bowles WH, Thompson LR. Vital bleaching: ‘The effects of heat and hydrogen peroxide on pulpal enzymes. J Endodont 1986;12(3):108- 112. . Cohen SC, Chase C. Human pulpal response to bleaching proce- dures on vital teeth, J Endodont 1979;5;134-138. Griffin RE, Grower, ME. Effects of solutions used to treat dental fluorosis on permeability of teeth. J Endodont 1977;11:391-343.References 23 Hislam.net Problem 20. a 22. 23. 24. Ledoux W, et al. Structural effects of bleaching on tetracyel stained vital rat teeth, | Prosthet Dent, 1985;54:55-59. Lisanti VE, Zander HA. Thermal injury to normal dog teeth. J Dent Res 1952;31;548-558 Nyborg H, Branstrom M. Pulp reaction to heat. J Prosthet Dent 1968;19:605-612. Postle HH et al. Pulp response to heat. J Dent Res 1959;38:740. Sakaguchi RL, Hampel AT. Bleaching of vital teeth, Clark’s Clin Dent 1991, vol 4:1-10. Haywood VB, Bleaching of vital and nonvital teeth. Gurr Opin Dent 1992;(March):142-149 Seale NS, Mcintosh JE, Taylor AN. Pulpal reaction to bleaching of teeth in dogs. J Dent Res 1981;60:948-953 Garber DA, Goldstein RE, Goldstein CE, Schwartz CG. Dentist- monitored bleaching: A combined approach. Pract Periodont Aes- thet Dent 1991;3(2):22-26Chemistry of Bleaching Howard Frysh, BDS, DDS Bleaching is a chemical process for whitening materials which is, widely used in industry, In dentistry, bleaching usually refers to products containing some form of hydrogen peroxide. ‘The three most prominent commercial bleaching processes are peroxide, chlorine, and chloride, in that order.! Peroxide bleaching requires the least time and is most com- monly used. The strength is designated most frequently by vol- ume rather than by percentage of peroxide, Thus, although they are interrelated proportionately, 27.5% hydrogen peroxide is termed 100 volume, 35% is 130 volume, and 50% is 200 volume, yolume indicating the volume of oxygen released by one volume of the designated hydrogen peroxide. Although bleaching processes are complex, the vast majority work by oxidation, the chemical process by which organic mate- rials are eventually converted into carbon dioxide and water. Wood burning in a fireplace is a common example of oxidation. ‘The differences between the oxidation that occurs with bleaching and that of burning wood are the rate of each reaction and the number of intermediate products produced. Burning rapidly transforms a substance into carbon dioxide, water, and heat. In comparison, bleaching slowly transforms an organic substance 25