Smile Design Treatment Modalities and Indications Tooth Hypersensitivity

        JULY 

Smile Design Treatment Modalities and Indications Journal Tooth Hypersensitivity

     

 .   ,  CDA Journal Volume 35, Number 7 Journal july 2007

departments 461 The Editor/The Making of Sausage 465 Impressions 531 Dr. Bob/No Apologies! features 473 Selected Topics in Esthetic Case Management: An Introduction to the Issue An introduction to the issue. Edmond R. Hewlett, DDS

475 Examination, Communication, and Implementation: Strategies for Successful Esthetic Dental Treatment This paper presents effective strategies for ensuring successful treatment outcomes in complex esthetic cases as well as provides approaches to patient assessment, diagnosis, and esthetic treatment delivery employing evidence-based methods and current technologies. Stephen R. Snow, DDS

487 Clinical Crown Lengthening in the Esthetic Zone: An Overview of Treatment Modalities and Their Indications Management of the periodontal-restorative interface is discussed and this article focuses on crown lengthening in the esthetic zone, reviewing contemporary treatment modalities, and their indications. Paulo M. Camargo, DDS, MS; Philip R. Melnick, DMD; and Luciano M. Camargo, DDS, MSEd

499 Etiology and Management of Whitening-induced Tooth Hypersensitivity Tooth hypersensitivity has long been and continues to be the most commonly reported adverse effect of vital tooth whitening with peroxide gels. This article reviews the multiple etiologic factors implicated in whitening-induced tooth hypersensitivity and the evidence for efficacy of various strategies for its management. Edmond R. Hewlett, DDS

507 Perspectives on the 2007 AHA Endocarditis Prevention Guidelines Between 2005 and 2007, the American Heart Association convened a consensus panel of experts to revisit the guidelines for the premedication of patients with cardiac defects prior to dental treatment. Presented in this article is a summary of the guidelines as well as commentary on the process. Thomas J. Pallasch, DDS, MS Editor CDA JOURNAL, VOL 35, N 7 º

The Making of Sausage ALAN L. FELSENFELD, DDS

fter the completion of dental school, general practice Otto von Bismarck has been quoted as residency, or specialty train- ing, most of us settle into a saying “Laws are like sausage, it is better private practice of dentistry. AAt that point, we become comfortable not to see them being made.” in what we do for a living. Our expertise increases with experience; we can do what we like to do in dentistry, and not do what we do not like. We get to treat The Walter Mitty in me says I feel for office is most difficult. The people who many wonderful patients, we make a there might be more to life than practic- do this have to deal with constant fund comfortable living, and we have fun at ing dentistry. My fantasy is to be a leg- raising by attending luncheons, dinners, work. Life is good. islator in the state assembly or senate. and cocktail parties. You must be vigilant For many of us this is idyllic. The Can you image the responsibility and and watch every word you say as you comfort level is good, as is the control of power these individuals possess? They could be misquoted. Having to deal with our environment. For others, it is possible govern our state, supposedly between special interest groups, especially when we reach a state of ennui. We begin to the sixth and 0th largest economy in you disagree with their cause, has to be wonder if there is anything else to do. the world, as they make the laws we use tedious. You are constantly in the public Can we continue to practice for the rest of to guide our lives. The ability to impact eye and may find it difficult to relax even our lives? Are we capable of anything else the people of our state and the direc- in your own community. Couple this with besides dentistry as a career? Can we con- tion they can provide is impressive. The the need to run for re-election on a regu- tribute or give back in any other manner? committees to hear proposed legislation, lar basis and the increasing tendencies for Many of us go through similar introspec- testimony, and debate are all part of a “dirty” political campaigns, and one can tive analysis from time to time. process that makes this a democracy. understand the negative aspects of the There are numerous ways we can Even party politics, which at times can election process. show our “stuff” outside the office. Many be a difficult thing, can have positive We are fortunate to have colleagues of us get involved in community service rewards when it is perceived as the cor- who have accepted that challenge and in the delivery of health care to under- rect approach to a matter. What a way to became legislators. All of us know of the served groups. For others, church and have legacy in this world. accomplishments of Sen. Sam Aanes- community service activities, or social I would like to be a legislator. I would tad and Assemblyman Bill Emmerson. involvement allow us to express ourselves not like to become a legislator. Otto von They have represented Californians and in different venues. Those of us who are Bismarck said “Laws are like sausage, it is dentistry well. There are others, such deeply involved in dental politics are yet better not to see them being made.” This as Sam Wakim, who seek a seat in state another group trying to contribute at a analogy can be carried over to the process government in a contemporary election. different level. of getting elected to a position. Running Some dentists are achieving success at the

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local level in municipal governments and on school boards with the possibility they can advance their political careers in time. At a recent American Dental Associa- tion legislative leadership conference, we mourned the recent passing of Charlie Norwood, a dentist who represented all of us well in Congress. Several senators and representatives encouraged us to be involved nationally to have input into our profession. We need to support those who can rise to this level of participation. It is important to encourage more individu- als who have the desire to be involved with politics, not only at the association level, but also in local, state, and national positions. Offer them financial help as you can, for campaigning is impres- sively costly. Vote for them if you are in their district. Hosting coffees and other receptions will be beneficial. Helping in their campaign offices stuffing envelopes, making telephone calls, and distributing literature are all part of the workload that needs to be completed. Those of us who become legislators are people who have given up their dental practices to move to a more global level of politics. They do well for themselves and they do well for dentistry. They serve den- tistry well and show dentists can contrib- ute back to the community. We need to continue to support such individuals and we will all be better served by doing so. I will never become a legislator, and that might be a good thing. But I am grateful that we have many friends who represent our interests well.

Address comments, letters, and questions to the editor at [email protected].

462 J U LY 2 0 0 7 Impressions CDA JOURNAL, VOL 35, N 7 º

The High-performance Dentist BY DEBRA BELT If stress is too high or too low, perfor- mance goes down. This basic principle was at the heart of a presentation by Ben Bernstein, PhD, a performance psychologist and speaker at CDA Spring Scientific Session in May. More than 200 dental professionals turned out to listen to Bernstein, a perfor- mance psychologist who coaches people in “high-stress, high-performance jobs,” including professional athletes, opera singers, dentists, instrumentalists, attor- neys, actors, physicians, business execu- tives, and students taking tests that will shape their lives. Bernstein said dentists fall into this category because they often deal with people who are afraid, which makes things difficult. Bernstein is on the ADA’s national speaker’s circuit and is a consultant to the University of California, San Francisco, School of Dentistry. CONTINUES ON 470

Zimmer Contour natural-colored base for Ceramic Abutment an esthetic, all-ceramic J crown. ADA Legal Division Updates Zimmer Dental Inc. Antitrust Publication announced the launch of Crafted from high- the Zimmer Contour strength zirconia material, In an effort to keep member Ceramic Abutment. it is natural looking and Engineered to work with contains no visible metal dentists and tripartite societies the Tapered Screw-Vent margins. For more aware of antitrust developments, Implant System, the information, go to www. Zimmer Contour Ceramic zimmerdental.com or call the ADA’s Division of Legal Affairs Abutment provides a (800) 854-7019. has updated its publication Anti- trust Laws in Dentistry. It is important for dentists to Creation ZI-F zirconium oxide zirconium oxide is another F have some grounding in the antitrust laws to protect against taking frameworks, but also as a bonus: The new veneering Willi Geller has brought layering material for the system is also impressive on undue legal risk when it comes to issues such as fee setting and onto the market a new, pressable ceramic because of its uncompli- practice mode,” according to the publication. “Dentists with baseline aesthetically altered Creation CP ZI. Its high cated handling. For more zirconium oxide ceramic. durability and light information, go to www. knowledge of antitrust have an added arrow in their quiver when play- Creation ZI-F has an conductivity with creation-willigeller.com. ing the game of competition.” extremely high feldspar content – for light The antitrust primer is available online as a member benefit, in dynamics equivalent to PDF format, at www.ada.org/goto/antitrust. For more information natural teeth – and is exceptionally versatile. It about this resource call the ADA toll-free, 800-621-8099, ext. 2874. is suitable not only for veneering all kinds of

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Patients With Type 2 Diabetes Helped at Kyushu Dental College. “However, this by Periodontal Therapy was just a preliminary study and more Researchers from Kyushu Dental research should be conducted to evaluate College in Kitakyushu, Japan, investigated how periodontal disease aff ects both the impact of periodontal therapy on people with and without diabetes.” patients with Type 2 diabetes, as com- It has been found that periodontal pared to nondiabetic patients, and found disease and diabetes can lead to ath- that periodontal therapy decreased lipid erosclerosis. It has been thought that “Our research peroxide, an oxidative stress index, in oxidative stress is linked to heart disease diabetic patients. because oxidation of LDL (low-density emphasized one In their study that appeared in lipoprotein) in the endothelium is a of the benefi ts the November issue of the Journal of precursor to plaque formation. Recently, Periodontology, patients with Type 2 oxidative stress has emerged as an of having diabetes and periodontal disease who important factor for atherosclerosis in periodontal receive periodontal therapy see levels of patients with diabetes. oxidative stress, a condition in which “We hear every day about how more therapy for antioxidant levels are lower than normal, and more people are being diagnosed patients with reduced to the same levels as nondiabetic with diabetes,” said Preston D. Miller, patients. Jr., DDS, and president of American diabetes.” “Our research emphasized one of the Association of Periodontology. “Th is KAZUO SONOKI, MD, PHD benefi ts of having periodontal therapy for research confi rms that patients with patients with diabetes,” said one of the diabetes should be especially conscious study authors, Kazuo Sonoki, MD, PhD, of their periodontal health.”

UPCOMING MEETINGS Zimmer One-Piece Implant Now Available 2 0 0 7 in 4.7 mm Diameter D June 27-July 1 Academy of General Dentistry Annual Session, San Diego Convention Center, Zimmer Dental Inc. 888-243-3368. announced the addition of the 4.7 mm diameter Aug. 4 31st Annual Scripps Symposium on Oral Medicine, San Diego, Zimmer One-Piece Implant scripps.org/conferenceservices, 858-587-4404. in straight and angled versions. Also available in Aug. 22-24 International Society for Breath Odor Research Seventh International 3.0 mm and 3.7 mm Conference, Chicago, Bill Bike, [email protected] or 312-996-8495. diameters, the Zimmer One-Piece Implant Sept. 27-30 American Dental Association 148th Annual Session, San Francisco, ada.org. combines the design Contour Abutment, features of the renowned off ering a unique one- Nov. 27-Dec. 1 American Academy of Oral and Maxillofacial Radiology 58th Annual Session, Tapered Screw-Vent piece solution for fast, Chicago, aaomr.org. Implant with the prepared convenient immediate margins of the Hex-Lock restoration with minimal 2 0 0 8 or no abutment preparation. For more May 1-4 CDA Spring Scientific Session, Anaheim, 800-CDA-SMILE (232-7645), cda.org. information, go to www. zimmerdental.com or call Sept. 12-14 CDA Fall Scientific Session, San Francisco, 800-CDA-SMILE (232-7645), cda.org. (800) 854-7019.

Oct. 16-19 American Dental Association 149th Annual Session, San Antonio, Texas, ada.org.

To have an event included on this list of nonprofit association continuing education meetings, please send the information to Upcoming Meetings, CDA Journal, 1201 K St., 16th Floor, Sacramento, CA 95814 or fax the information to 916-554-5962.

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Biotene Denture Grip D Specifi cation Approved for Shipping and Storing Dental Amalgam Waste Biotene Denture Grip is The American National Standards Institute has approved ANSI/American Dental the latest innovation for Association Specifi cation No. 109 for Procedures for Storing Dental Amalgam Waste and denture wearers suff ering from dry mouth. Without Requirement for Waste Storage/Shipment Containers as an American National Standard. enough saliva to provide Biotene Denture Grip was The specifi cation was developed by the ADA Standards Committ ee on Dental Prod- adequate adhesion, gum specially formulated for tissue contacting the den- denture wearers with dry ucts, with representation that included the Environmental Protection Agency. ture may become chafed, mouth. Its unique hydro- The ADA said one of the purposes for the specifi cation is to encourage amalgam irritated, and infected due gel chemistry provides a recycling by making it more eff ective and easier for the dental offi ce. The specifi cation to daily wear and harmful maximum hold while the bacteria production. proven patented salivary describes procedures for storing, and preparing amalgam waste for delivery to recyclers enzyme system soothes or their agents for recycling. In addition, it gives requirements for storing and/or shipping minor irritations, protects against fungal build-up, amalgam waste, according to the ADA. and fi ghts odor-caus- The ADA recommends that dental offices use this specification in ing bacteria. For more conjunction with the ADA’s Best Management Practices for Amalgam Waste. information, call (800) 922-5856 or go to www. Additionally, the ADA recommends dental offices select a recycler whose biotene.com. procedures comply with ANSI/ADA Specification No. 109. ANSI/ADA Specifi cation No. 109 for Procedures for Storing Dental Amalgam Waste and Requirements for Dental Amalgam Waste Storage/ Shipment Containers is available through the ADA catalog at www.adacatalog.

Alternative to Antibiotics May Be More tin hypersensitivity, reduced infl amma- Eff ective, Less Harmful tion of the tissues surrounding the teeth, Photodynamic therapy may be an and allows tissues to repair faster.” eff ective way to treat the bacteria associ- Photodynamic therapy may be an ated with periodontal diseases, and could alternative to antibiotic treatment, which provide a better option than antibiotics or is becoming increasingly important as other mechanical methods for treating peri- antibiotic resistance increases. Th is form odontal diseases, according to a new study of therapy involves two stages: fi rst, a published in the Journal of Periodontology. light-sensitive drug is applied to the area. Researchers at São Paulo State Second, a light or laser is shone on that University found that using photody- area. When the light is combined with namic therapy was an eff ective method the drug, phototoxic reactions induce the to minimize destruction of periodontal destruction of bacterial cells. tissue that can accompany treatment for “Th is is an exciting fi nding,” said Pres- periodontal diseases. In a rat population, ton D. Miller, Jr., DDS, and president of photodynamic therapy did minimal dam- American Association of Periodontology. age to periodontal tissues, in comparison “PDT may be an eff ective therapy for the to other techniques including scaling and treatment of periodontal diseases. While root planing, and antibiotic therapy. patients have many options for treating “We found that PDT is signifi cantly their periodontal diseases, PDT could prove less invasive than other treatments for to be a preferable alternative to antibiotic periodontal diseases,” said study author therapy. Unfortunately, long term antibi- Dr. Valdir Gouveia Garcia, of the Depart- otic therapy not only decreases the drug’s ment of Periodontology at São Paulo State eff ectiveness, but also may lead to the University. “It can provide improved den- development of drug resistant organisms.”

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Surge in Arthritis Cases Predicted By 2030, Americans with arthritis and other rheumatic diseases will surge by 46 percent (roughly 67 New Gingival Shades million people), or about 25 percent of the population, for Creation CC and according to federal public health offi cials. Creation ZI D In a recent issue of the Wall Street Journal, Creation Willi Geller has ZI Kit contains the same popular retirement states - Arizona, Florida and expanded its ceramic shades but an additional Nevada - will feel the brunt more acutely. The Centers range with high-quality Frame Shade instead of gingival shades for metal- the opaquer. For more for Disease Control estimated that arthritis cases in lo- and zircon ceramic. information, go to www. Arizona will increase by 87 percent, or 1 million people. The Creation CC Gingiva creation-willigeller.com. While health offi cials noted medication can Kit is available with paste and powder opaquer in six alleviate some pain and immobility problems shades: purple, dark and associated with arthritis and other age-related light pink, fl amingo, rose degeneration of the joints, physical activities are a and dark pink opaque; and a neutral ceramic. Creation more long-term solution for those with arthritis and those at risk for the disease.

Dean Bertolami Heads to the Big Apple “Under Mike Alfano’s deanship, the Col- Long known as a leader in the dental lege of Dentistry went through a remark- research, education, and clinical com- able transformation: Th ere was a renewed munities, Charles N. Bertolami, DDS, and powerful emphasis on research, DMedSc, has been named the 4th dean the facilities were upgraded, the role of of the New York University College of dentistry was expanded, new healthcare Dentistry. He will assume the post at collaborations were envisioned, the qual- NYU’s 42-year-old College of Dentistry ity of students improved greatly, and the on Sept. . He currently is in his 2th year College of Nursing became part of the as dean of the University of California, Dental College. Finding a successor who San Francisco, School of Dentistry. could sustain that momentum was a sig- In addition to expanding the school’s nifi cant challenge, but Charles Bertolami research capacity, Bertolami also has is ideally suited not only to sustain it, but enhanced the school’s clinical and teach- accelerate it.” ing programs, including renovating clinics Robert Berne, NYU’s senior vice and laboratories; implementing a new cur- president for Health, said, “If you go to riculum reinforcing integration of basic a dentist in the United States, chances and clinical sciences in dental education; are -in-2 that you will be cared for by a establishing and expanding joint degree graduate of the NYU College of Dentistry. programs; and establishing a year-long We have an obligation, therefore, to ensure postbaccalaureate program for students that the leader of the school is among from economically or educationally the best in the country, a person who can disadvantaged groups. Th e UCSF School set an agenda for excellence in research, of Dentistry has also led the nation in education, and clinical care delivery and overall NIH funding for dental schools. envision new possibilities for the role of John Sexton, NYU president, said, the profession within the health care fi eld.”

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USC-led Researchers Use Stem Cells to Regenerate Parts of Teeth A multinational research team headed Health, had utilized dental pulp stem cells. by University of Southern California Shi found the new technique to be superior. School of Dentistry researcher Songtao “The apical papilla provides better Shi, DDS, PhD, has successfully regener- stem cells for root structure regeneration. ated tooth root and supporting periodon- With this technique, the strength of the tal ligaments to restore tooth function in tooth restoration is not quite as strong an animal model. The breakthrough holds as the original tooth, but we believe it is significant promise for clinical application sufficient to withstand normal wear and in human patients. The study appeared in tear,” Shi said. the inaugural issue of PLoS ONE. Shi hopes to move the technique to Using stem cells harvested from the clinical trials within the next several years, extracted wisdom teeth of 8- to 20-year a potential boon for dental patients who New gIDEPod Personal patient surgical videos. olds, Shi and colleagues have created are not appropriate candidates for dental Study Station: Flexible The iPod contains more than 40 hours of education sufficient root and ligament structure implant therapy, or would prefer living Dental Learning in Your Pocket and sits neatly in its own to support a crown restoration in their tissue derived from their own teeth. customized slot within animal model. The resulting tooth restora- “Implant patients must have sufficient Global Institute for Dental the monitor. It is tion closely resembled the original tooth bone in the jaw to support the implant. Education has launched its lightweight and fits easily in function and strength. For those who don’t, this therapy would newest education product, into a briefcase for carrying from home to The technique relies on stem cells be a great alternative,” Shi said. the gIDEPod Personal Study Station. The station, office, to travel. For more harvested from the root apical papilla, According to Shi, the not-so-distant complete with iPod and information, go to www. which is responsible for the development future may be one in which not only 7-inch LCD monitor comes globalinstituteonline.com. of a tooth’s root and periodontal ligament. wisdom teeth, but those baby teeth once loaded with 20 DVDs, Previous studies, conducted by Shi and left to the tooth fairy for a pittance, will video interviews with Stan Gronthos at the National Institutes of become valuable therapeutic tools. experts and select live

TABLE 2 CORRECTION Patient History in Evaluation for Xerostomia v An incorrect title Medical History Past and present medical diagnoses appeared on a table in Past and present medical treatments the June issue of the Undiagnosed symptoms Journal. The corrected table appears at left. It Medication History Name of medication is Table 2 for “Dental Dosage/change in dosage Management of Xerostomia — Reason for taking Opportunity, Expertise, How long taken Obligation” by Cynthia L. Kleinegger, DDS, MS. Dental History Types of dental treatment Extent of dental treatment Oral home care practices Dietary habits

Patient Perception of Do you have a sticky, dry feeling in your mouth? Oral Condition Do you have trouble chewing, swallowing, tasting, or speaking? Do you have trouble wearing a denture? Do you have a sore or burning feeling in your mouth? Do you have bad breath?

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DENTIST, CONTINUED FROM 465

“Stress is a function of disconnection TO STAY CONFIDENT: in the body, mind, or spirit,” he said. ■ Confide in a trusted source and let For optimal performance, people need go of negativity. to be connected in all three areas. He out- ■ Reflect back something accurate and lined the qualities of being calm, confident, positive. and focused, which reflect respective con- ■ Envision taking small, manageable nections with the body, mind, and spirit. steps. Awareness of disconnection is crucial ■ Minimize negative self talk, which to keeping stress at bay and performance diminishes confidence. at a peak. To keep calm, confident, and ■ Keep your “personal radio” tuned to focused, Bernstein shared the following the positive. Bernstein encouraged listeners tools to help reconnect: to be aware of thoughts such as I can’t, I TO STAY CALM: don’t, I’m not.” He asked all attendees think ■ Breathe deeply down to your belly. of their initials with the letter “K” in front ■ Ground yourself. Feel the floor. — i.e., KAF, KPR, or KRT. “Think of your “Give yourself Release tension. inner voice as your personal radio station, directions to ■ Sense your surroundings through broadcasting all day, every day,” he said. your five senses. Bernstein had partici- “Give yourself directions to stay on track.” stay on track.” pants perform a simple exercise where ■ Cultivate attributes that help main- BEN BERNSTEIN, PHD they kept their head straight while turn- tain confidence including being: fearless, ing their eyes to upper left and upper effulgent, loyal, patient, resolved, and right, and then lower left and lower right. appreciative. This practice engages peripheral vision TO STAY FOCUSED: and increases awareness. ■ Stop and ask, “Is this distraction ■ Try “the wedge.” Bernstein intro- taking me to my goal?” duced a practice referred to as the wedge, ■ Listen to your inner voice for the which activates all three techniques: Stand- next step. ing, take a moment to breathe out, visual- ■ Fulfill your purpose; see yourself izing breath reaching down the front of taking action and getting back on track. the body and all the way to the floor. Then ■ Cultivate attributes that help main- breathe in, imagining your breath traveling tain focus including being: determined, up the back of the body to the head. passionate, engaged, fulfilled, attentive ■ Cultivate attributes that help main- and patient. tain a calm demeanor including being: Bernstein’s presentation at Spring receptive, accepting, composed, grateful, Session was hosted by the CDA Well-Be- patient, and harmonious. ing Committee that offers support to members, families, and staff struggling with drug or alcohol addiction. During the lecture, he touched upon the consequenc- Honors es of too much stress including neglecting self-care and avoiding treatment that can Grayson Marshall, DDS, professor and This year’s Craniofacial Biology Research spell trouble for dental professionals. division head of Biomaterials, University of Award has been presented to Karin Vargervik, In closing, Bernstein reiterated the California, San Francisco, School of Dentistry DDS, professor and interim chair, Division has been given the 2007 Wilmer Souder Award of Orthodontics, Department of Orofacial importance of positive connection through for research in the field of dental biomaterials Services at the University of California, San expressing appreciation for yourself and for science by the International Association for Francisco. The award was part of the recent others. “As professionals, you have the abili- Dental Research. 85th General Session of the International ty to educate, inspire, and empower patients Association for Dental Research. to be healthy,” he said. “You are making a sacred contribution to people’s lives.”

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Selected Topics in Esthetic Case Management

EDMOND R. HEWLETT, DDS

GUEST EDITOR he importance of an attractive smile in contem- cases. This detailed article provides porary culture — for better or worse — cannot approaches to patient assessment, Edmond R. Hewlett,DDS , is an associate professor, be overstated, and has been extensively stud- diagnosis, and esthetic treatment ,2 restorative dentistry, ied. This social imperative for good looks and delivery employing evidence-based University of California, the pervasive marketing of dental products and methods and current technologies. Los Angeles, School of Tprocedures to consumers have combined to create an unprec- Management of the periodontal-re- Dentistry. He has edented demand for appearance-related dental treatment. storative interface is discussed by Drs. maintained a private practice in restorative Concurrent with this phenomenon is the inexorable pro- Paulo M. Camargo, Phillip R. Melnick, and and prosthetic dentistry gression of technology and the resultant array of diagnostic Luciano M. Camargo. Their article focuses at the UCLA Faculty Group and treatment advances presently available to practitioners. on crown lengthening in the esthetic Dental Practice. Collectively, these factors have positively impacted dental zone, reviewing contemporary treat- practice busyness as more individuals seek elective treat- ment modalities, and their indications. ments, and patients are benefiting from improved materials Finally, my paper addresses the techniques. It’s a good time to be a patient and to be a dentist. most common adverse event associated Despite the advances, however, many fundamental prin- with the most popular esthetic den- ciples of clinical dental practice remain unchanged. Specifically, tistry treatment: tooth hypersensitivity prudent case selection, thorough diagnosis, and meticulous plan- induced by peroxide-containing whiten- ning and execution of treatment — all with strict adherence to ing products. Current information on biologic and ethical principles — continue to define the standard etiology and management are provided. of care. These principles must be applied to elective improvement The authors hope you will enjoy this of dental esthetics with the same diligence as that which tradi- issue and find the information useful. tionally guides the prevention and management of oral disease. The authors of this issue’s articles have selected topics from the REFERENCES broad category of esthetic dentistry that cover some common 1. Eli I, Bar-Tal Y, Kostovetski I, At first glance: Social meanings clinical issues and reflect these principles of appropriate care. of dental appearance. J Public Health Dent 61:150-4, 2001. 2. Newton JT, Prabhu N, Robinson PG. The impact of dental Dr. Stephen R. Snow presents effective strategies for en- appearance on the appraisal of personal characteristics. Int J suring successful treatment outcomes in complex esthetic Prosthodont 16:429-34, 2003.

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Strategies for Successful Esthetic Dental Treatment STEPHEN R. SNOW, DDS

ABSTRACT The foundational principles of esthetic smiles reveal the direct influence of individual tooth alignment on dentofacial relationships. The use of clinical photography is an essential means to identify esthetic problems. Smile design provides an opportunity for effective communication to discuss treatment alternatives with the patient in the consultation process. The scope of treatment can be determined, and treatment limitations can be explained. Smile design findings influence preparation design, material selection, and laboratory communication for enhanced predictability and improved treatment success.

AUTHOR he prospect of performing The clinician needs an objective Stephen R. Snow, DDS, is cosmetic dental treatment is strategy to navigate through the patient visiting faculty, University appealing. Recent media at- examination and evaluation process. of California, Los Angeles, tention has heightened public With objective consideration of the Center for Esthetic Den- awareness and increased possible treatment alternatives that tistry; director, PERFECT Perspectives Advanced demandT for the services. Branding could be applied to meet the patient’s Dental Seminars, Danville, techniques that market specific products goals, the proper treatment options Calif., and in private prac- to patients rather than clinicians have can be presented and excellence in tice emphasizing cosmetic enhanced patient inquiries for care as dental treatment can be delivered. restorative dentistry in well. Since the services are often elec- Danville. tive and directly requested by many Esthetic Principles patients, their willingness to accept Clinicians must be mindful of es- treatment despite insurance coverage thetic standards in evaluating how best limitations may not be as restricted to meet patient expectations. The more as with other treatment modalities. the elements of appearance deviate from Despite patient enthusiasm for op- known visual principles, the more likely tional procedures, however, the delivery patients will be disappointed with their of esthetic care presents many potential smile. These principles are not dogmatic problems. There are many treatment rules that must be applied and achieved alternatives available. Durability and for every patient. Some patients are often performance of competing materials disappointed with their appearance, how- systems can be questionable. The ap- ever, they compare themselves to social propriate scope of treatment may seem and entertainment icons and perceive that arbitrary. Selecting interdisciplinary they don’t measure up. Although patients strategies may be confusing as well. usually are focused on specific esthetic

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FIGURE 1. When viewed from a frontal perspective, the FIGURE 2. The Frankfurt horizontal (magenta) is paral- FIGURE 3. The proximofacial line angles combine with superimposed midline (magenta), upper/middle/lower lel to the horizon in this sagittal perspective view. The cervicofacial and incisofacial line angles to define the re- thirds of the face (yellow), and lower third anatomical maxillary lip is positioned approximately 4 mm posterior flective “face” that accentuated the tapered appearance relationships (green) of this face are well-proportioned to the E-plane (yellow) while the nasolabial angle (green) is in this case. An increase in chroma from central incisor to and conform to facial esthetic principles. approximately 95 degrees. canine is evident along with an anterior halo. complaints, they are often unaware of the males and 00 degrees to 05 degrees for that partially obscures the visibility of interrelation of multiple factors that com- females.,3,4 E-plane evaluation ideally the underlying tooth layers. Refraction bine to create the deficiencies they notice. reveals the maxillary lip is positioned 2 caused by the incisal table of anterior It is prudent for clinicians to implement mm to 4 mm posterior to line from tip teeth may scatter light to produce the a disciplined approach in the diagnosis of nose to tip of chin.,3,4 (FIGURE 2). appearance of a halo, a thin light line at and subsequent delivery of dental care. DENTAL ESTHETIC PRINCIPLES com- their incisal edges (FIGURE 3). Finally, the Esthetic principles can be categorized prise the nuances of contour and color appearance of tooth color is influenced in three general groups: facial esthetic characteristics of individual teeth. The by its surface topography.6,8 The anatomy principles, dental esthetic principles, contour of a tooth can be analyzed of developmental vertical undulations, and dentofacial esthetic principles. in three-dimensional views: from the the texture of lines and pits, and the FACIAL ESTHETIC PRINCIPLES comprise facial, interproximal, and incisal. The relative glossy luster of a tooth alter the the overall skeletal relationships that “face” of a tooth has been defined as reflective qualities of its surface (FIGURE affect the appearance of the middle and the reflective area inside the transi- 4). The more light is reflected and scat- lower face. From the frontal perspective, tional line angles of the facial surface.6 tered from the surface of a tooth, the the nasal, dental, and mental midlines Although the silhouette of each tooth less the underlying color is apparent. ideally should coincide with the facial contributes to its appearance, the light DENTOFACIAL ESTHETIC PRINCIPLES midline — a perpendicular line that reflection from the face of the tooth are somewhat more complex in that they bisects the interpupillary distance. The defines its apparent shape (FIGURE 3). represent a blend of both facial structures occlusal plane should be perpendicular The inherent layers of tooth com- and dental structures.9 Theses principles to the midline and parallel to the hori- position determine the characteristics are determined by tooth arrangement, zon.2,3 Attractive faces generally conform of its color appearance. The internal the position of a tooth in space relative to the rule of thirds — with the upper, dentin possesses the most chroma and the others in the arch. These principles middle, and lower face segments each opacity while the enamel is more trans- include the relative width and height of occupying approximately equal propor- lucent with significantly less chroma. the teeth in the anterior segment.,6, tions of the vertical dimension of the These optical properties combine with The Golden Percentage of .68 : .0 face.2,4,5 (FIGURE 1). Within the lower third the natural variations in thickness of can be converted and modified to the of the face, the distance from the base of each layer to produce a polychromatic Golden Percentage for assessment of the nose to the incisal edge/lips should shift within each tooth. Typically, there proportions and central incisor domi- represent approximately one-third of is also a polychromatic shift within the nance as well as bilateral symmetry of the space, while the distance from the arch in which the canine teeth have a maxillary anterior tooth width.0 incisal edges/lips to the chin occupies higher chroma and lower value than When viewed from the frontal aspect, the remaining two-thirds.3 Attractive that of the central incisors7 (FIGURE 3). the width of each maxillary anterior faces generally display an overall sym- Additional color nuances are cre- tooth is measured mesiodistally at its metry.2,5 From a sagittal perspective, the ated by the subtle surface character- maximum visible height of contour as nasolabial angle typically should fall in istics of teeth. A whitish surface haze viewed from the frontal aspect. The the range of 90 degrees to 95 degrees for may be present to form an enamel veil individual width of each tooth is divided

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FIGURE 4. A combination of vertical developmental FIGURE 5. The mesial axial inclination (blue) increases FIGURE 6. The smile line generally follows the curva- undulations, random surface irregularities and a satin from central incisor to canine and then remains constant ture of the mandibular lip, and the esthetic zone is appro- quality luster all contribute to scattered light reflection in the posterior segment. The apical migration of the in- priately filled with “white space.” The overall visual impact that partially obscures the visibility of the underlying terproximal contacts with each successive distal contact of the arrangement is pleasing from social distances tooth color. matches the associated incisal embrasure (green). The despite obvious asymmetry in lateral incisor rotation. “high-low-high” gingival zenith pattern is ideal in this case. by the sum total to reveal the percent- interproximal contacts on an individual The distal position gradually increases age that each tooth contributes to the tooth reveals the distal contact is usu- from the central incisor to the canine. total canine-canine width. As an initial ally positioned further toward the apical While each of these dentofacial reference, the width percentage of the than the mesial contact. As a result, the principles can be evaluated indepen- maxillary central incisors, lateral incisors, incisal embrasure form in the anterior dently, they are all affected by four and canines should approach 22 percent; also exhibits a gradation — increasing specific tooth arrangement factors 6 percent; and 2 percent, respectively. in depth from central incisor through that affect the appearance of a smile: The width-height ratio of a maxillary canine (FIGURE 5). While minor differences ■ Arch form,0, central incisor should approximate 75 are desirable, pleasing smiles exhibit a ■ Buccolingual position of each tooth, percent.,2,5 While these ratios produce high degree of radiating symmetry.2,5,6 ■ Mesiodistal position of each tooth, pleasing anterior proportions represent- Dentofacial principles include evalu- and ing the “media look” that patients may ation of the collective appearance of the ■ Rotation of each tooth. visualize and desire for their own smiles, teeth in relation to the lips. Generally, the If a smile presents a smooth evenly minor variations are appropriate to blend smile line should create a gentle, con- curved arch form free of buccolingual dis- with differing arch form and tooth ar- vex curve that follows the lower lip-3,6,2 placement, mesiodistal displacement, and rangement appearance that accompany (FIGURE 6). The oral structure revealed in rotation, the ideal dentofacial relation- different facial shapes (i.e., longer versus a full smile should maximize white space ships are often present as well, creating shorter, wider versus narrower).,5,,2 (teeth) while appropriately minimizing a pleasing appearance. A tooth arrange- A line extending from the height of black space (diastemas, excess buccal ment with a collapsed palatal vault, the emergence of the tooth from the free corridor space) and pink space (gingival buccoverted teeth, linguoverted teeth, gingival margin to the center of the incisal display).6 When the lips are retracted, the overlapped teeth, diastemas, or rotated edge or incisal cusp tip implies the align- gingival frame components of the smile teeth often exhibits many violations of ment of the axis of each tooth as its root can be evaluated. Ideally, the emergence dentofacial principles and is unesthetic. extends into the alveolus. The maxillary of the maxillary anterior segment should anterior teeth ideally display mesial axial form a symmetrical “high-low-high” pat- Documentation and Communication inclination gradation, with the central tern in which the free gingival margin of While patients are often aware of incisors appearing to be the most vertical the canine and central incisor are at the esthetic problems they want resolved, and the lateral incisors and canines each same height and the free gingival margin they are often unaware of the interrela- tipping more toward the midline5,6 of the lateral incisor is positioned just tion of tooth arrangement factors in (FIGURE 5). Beyond the canines, the re- incisal to that,5,6,9 (FIGURE 5). The gingival smile design. Even though there may be maining posterior teeth should display an zenith represents the most apical point several elements simultaneously con- inclination that is parallel to the canines.5 at which each tooth emerges from the tributing to make a smile unattractive, In an analysis of the normal position free gingival margin. For an esthetically it is only after the chief complaint is of interproximal contacts from mesial to pleasing smile, it should be positioned resolved that the next most egregious distal within an arch, there is an apical distally to the center of each tooth esthetic violation may become appar- migration. The occlusocervical position of within the maxillary anterior segment. ent to the patient. The cosmetic dentist

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FIGURE 7. Wand-type intraoral cameras FIGURE 8. Digital single lens reflex camera FIGURE 9. This image was captured with offer convenience for digitally capturing freeze systems allow use of macro (close-up) lenses with a wand-design intraoral camera. The pixel frame images or video sequences. The small manual focus for repeatable diagnostic magnifica- dimensions of the image were 640 x 480. size of the wand unfortunately mandates tion. The large camera body can accommodate a Note the uneven lighting, grainy/pixelated the need for a small internal sensor with low large sensor offering high resolution and superior appearance, and wide angle distortion. resolution. The images may appear pixelated color accuracy. and distorted. should possess a wealth of knowledge and reflex camera systems (FIGURES 7-8). Both tography. Although there are a many experience in order to make appropriate systems record light with a solid-state digital cameras on the market for general treatment recommendations to address sensor through an electrical reaction. A photography that all allow rapid visual- these concerns. Clearly, this perspective charge-coupled device, CCD, or a com- ization of captured images, repeatable is not shared initially by the patient. The plimentary metal oxide semiconductor, diagnostic dental photography requires clinician must have a means to introduce CMOS, photodiode detector stores an a digital single-lens reflex camera system smile design principles to patients for electric charge that corresponds to the that allows interchangeable lens selec- their consideration prior to treatment. amount of light that strikes each por- tion.4 Macro lenses with a fixed focal Routinely, dentists perform compre- tion of the sensor. Initially the electrical length designation of 00 mm to 05 mm hensive evaluations for patients as they energy is converted into individual dots of provide the ideal combination of mag- begin care in the office. Comprehensive digital color information that are com- nification ability and working distance clinical examination includes reviewing bined to create the final image. Each dot convenience for dental purposes.5 The the medical history, assessment of tem- of color data represents the basic visible resolution and color accuracy are far supe- poromandibular joint and musculoskeletal unit of the detail of the digital image. rior to that of wand-type systems (FIGURE function, evaluation of occlusal function Each picture element is called a “pixel.”3 10). Manual focus capability is required and harmony, assessment of surrounding The greater the number of pixels captured to create images with useful magnifica- soft tissues, examination of periodontal by CCD or CMOS sensor, the better the tion ratios ranging from : (for close-up tissues, and an evaluation of each tooth, quality of the recorded image detail.3,4 views) to :0 (for full-face images). both clinically and radiographically. The first wand system was the Fuji The camera body coordinates the func- Beyond objective written documenta- Dentacam introduced in 986. Since tions of the image capture by regulating tion regarding the presence or absence that time, several manufacturers have the amount of light that is allowed to ex- of positive findings in these categories, entered the marketplace with similar pose the digital sensor with the exposure the dentist must also consider methods products, but the units have become time (shutter speed) and lens opening for the documentation of the subjective more compact and affordable. The wand diameter (aperture).5 In addition to af- esthetic elements of the smile. There is design mimics an intraoral dental mirror fecting the amount of light that enters no question that photography presents to facilitate a visual “tour” of the mouth the camera, the aperture also affects the the most effective way to record pretreat- with the potential for freeze frame as well amount of the scene that appears to be in ment conditions and post-treatment as video capture. Input and subsequent focus. When a small diameter aperture is results. Accurate clinical photography has image review are directly stored to and used, a larger portion of the scene in front become an integral part of the standard retrieved from a local computer hard drive and behind the actual focal point appear of care for appropriate documentation of with proprietary software. While these to be in focus as well.3 Camera systems the teeth and surrounding structures. systems are essentially “plug-n-play,” the that are capable of manual aperture set- There are currently two prevalent resolution and quality of the resulting tings to maximize the zone of focus are modalities used for clinical photography images is mediocre at best (FIGURE 9). ideal for dental documentation purposes. in the dental office: fiber optic “wand” Digital camera systems provide the Supplemental light is supplied by a dual- camera systems, and digital single-lens alternative method for intraoral pho- point strobe flash is best for intraoral

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FIGURE 10. This same tooth, as in Figure FIGURE 11. Laboratory shade images should FIGURE 12. Black and white (gray scale) images 9, but the image was captured with a DSLR. have a shade tab in the same plane as the aid in evaluation of value without the unwanted The pixel dimensions of the 2592 x 1885 after documented tooth. Beyond hue and chroma, misinterpretations that can be caused by adjacent cropping to match the perspective of Figure photographs are the most effective means to com- colors. Some DSLRs are capable of b/w capture, 9. Note the even illumination, lack of pixela- municate nuances in translucency, texture, incisal but color pictures can also be converted to gray tion, and improved color representation. effects, and contour. scale with computer software.

purposes. A twin-flash design may offer adequately captured (FIGURE 11). Black the best combination of soft, uniform and white photographic images can illumination while simultaneously re- provide a visual description of surface vealing surface detail, color transitions, texture, as well as an objective measure translucency variations, and crack lines.5 of tooth value (reflectivity)26 (FIGURE 12). The applications for digital intraoral Since laboratory technicians fabricate photography have greatly enhanced the restorations with stone models, photo- documentation of clinical evaluation. graphic images of provisional restorations FIGURE 13. Maxillary anterior dentition with Photographic images are indispensable are imperative to visualize dental propor- mild diastemas prior to treatment (a) and with diastema closure after conservative direct resin for the documentation of pretreatment tions in relationship to surrounding soft restorations (b). Tooth proportions were improved conditions, clinical treatment steps, and tissues.27 Photographs enable technicians simultaneously with the alteration in tooth post-treatment results. Patients are often to evaluate smile line harmony, horizontal contour. motivated to enroll in dental treatment occlusal plane orientation, and white/ able. The best dental treatment recom- through co-diagnosis with preoperative black/pink space proportions revealed in mendations and subsequent dental care digital images.6,7 Clinicians can utilize a full smile. Photographs of lips in repose delivery decisions are evidence-based, photographs of treatment performed for show the incisal edge display at rest.28,29 relying on sound clinical research to other patients to provide an example of Photographic images of postoperative re- formulate treatment protocol.3 specific procedures and the results they sults can provide feedback for self-assess- Advances in adhesive dental technol- can achieve.8,9 Photographic images ment to each member of the restorative ogy have allowed clinicians to consider augment both oral and written clarifica- team for the opportunity to learn and and deliver esthetic treatment modalities tion in presenting informed consent improve future results.30 Digital images of that were previously not possible. Direct prior to commencing treatment.7,8,20,2 pre-existing clinical conditions can vali- resin restorations provide a plethora of Additionally, visualization of potential date and verify the need for treatment de- predictable treatment possibilities for mi- treatment results can stimulate patient livery when submitting insurance claims.9 nor alterations in tooth contour or color involvement that develops the relation- with minimal preparation.32,33 (FIGURE 13). ship between the clinician and patient.22,23 Restorative Alternative Perspectives Stacked powder-liquid ceramics offer ad- During delivery of esthetic dental The clinician must deliver care that ditional improvement in surface durabil- treatment, color photographs are in- satisfies the patient subjectively and the ity and color stability through indirect dispensable in communicating shade clinician objectively. To be successful, the fabrication. Since these conservative nuances to laboratory technicians.24,25 treatment must meet or exceed patient restorations can be fabricated with thin The images communicate the color of expectations. As a dentist considers the labiolingual dimensions, they require min- surrounding dentition as well as un- wide array of possible esthetic treatment imal tooth reduction and afford maximum derlying preparations. Proportions and recommendations for their patients, the enamel preservation. By bonding directly positions of enamel tints, characteriza- choices can seem daunting. Just because to enamel, the adhesive interface is dura- tion intensities, degree of translucency, a treatment modality is possible, it may ble, predictable, and maximized.34,35 Deliv- depth of opacity, and incisal edge can be not be predictable — or even advis- ery of these cosmetic services requires sig-

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FIGURE 14. Maxillary dentition undergoing FIGURE 15. Laboratory fabrication of a treatment for large diastema closure with prepa- zirconia-core crown. Fluorescent masking layer rations designed to maximize enamel retention to applied to the white zirconia coping (a) is unde- FIGURE 16. The Frankfurt horizontal and interpupillary and enamel margins (a) and after cementation of tectable within the body build-up with porcelain midline are recognizable landmarks that can be utilized to pressed ceramic restorations (b). margin, dentin layers and incisal window (b), or the create an alignment grid to capture images with repeat- completed crown (c). able, diagnostic angulation. nificant skill. Ceramic construction with parallelism of the opposing axial walls.47 the material itself.55 These criteria often liquid-powder systems requires the use Pressed ceramic systems were devel- result in the complete removal of tooth of refractory dies or twin foil techniques. oped as an esthetic restorative alternative enamel in all prepared areas.56,57 Research Considerable experience is required of to overcome some of these obstacles. has shown that tooth flexure increases the laboratory technician.36 Furthermore, Pressed ceramic restorations provide significantly with the percentage of tooth clinical circumstances don’t always meet enhanced cohesive strength to expand structure removed.58,59 Since the ulti- the ideal criteria required for placement of the amount of unsupported restorative mate strength of a pressed restoration conservative esthetic restorations. Broken material that can augment the contours of is directly dependent on the strength of teeth, missing enamel, and parafunctional teeth without the need for a metal core.48- the underlying tooth structure, increased habits all present challenges that render 50 This restorative strategy presents many tooth flexure can result in increased the long-term outlook for conservative advantages. By eliminating the internal ceramic fracture. If pressed ceramics are cosmetic restorations questionable.37-42 metal coping, excessive opacity is reduced, utilized to create the illusion of improved Ceramo-metal restorations were previ- and improved optical properties are more tooth alignment, the resulting combina- ously the only viable restorative option if readily achieved.5 The ability to etch the tion of tooth reduction, tooth flexure and additional strength was needed for clinical ceramic interface allows adhesion for occlusal forces may create a combination durability by virtue of the support of their restoration retention. Preparation design that could result in restoration failure.60-62 metallic inner core. While the restorations can be more conservative, and partial More recently, alternative ceramic have proven to be predictable, they have coverage restorations are possible materials have been developed to re- two significant liabilities.43 The metallic (FIGURE 14). Translucent luting cements place the metal in strengthened-core core is both dark and opaque. The esthetic allow the placement of supragingival porcelain restorative strategies. Alumina consequences are problematic. The core margins. Pressed ceramic fabrication tech- and zirconia-based materials provide casts a shadow that prevents light trans- niques allow the dental laboratory to cre- a densely sintered crystalline struc- mission into the root.44,45 The overlying ate ceramic margins with procedures that ture with physical properties that rival gingiva can appear objectionably dark. The mimic the lost-wax techniques utilized metal-based systems.63-65 Even though color of the core material has to be opti- in cast gold restorations.52 With famil- preparation depth requirements are the cally masked. The preparation dimensions iar fabrication strategies and desirable similar to ceramo-metal restorations, must necessarily be deep to allow room optical properties, the esthetic treatment the white ceramic core is somewhat for masking techniques and materials. modalities could be offered by a wider easier to mask.66,67 (FIGURE 15). Laboratory Even with an aggressive preparation spectrum of dentists being supported fabrication of the ceramic copings can design and subgingival margin placement, by a larger number of technicians.53,54 be outsourced to centralized locations significant technical skill is required to Unfortunately, the pressed ceramic and then returned to the initial lab for mask the core without creating an opaque fabrication process came with limitations completion of contour and shade match- appearance that is readily detectable.46 of its own. Although more conservative ing with standard veneering techniques Since ceramo-metal restorations were than that required for ceramo-metal resto- that mimic those used for ceramo-metal traditionally cemented, a circumferential rations, minimum preparation depths fabrication. Through the development preparation was mandatory, and reten- were still required by material manufac- of ceramic systems that utilize familiar tion was determined by the length and turers to meet the physical constraints of fabrication strategies and with improved

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FIGURE 17. A pretreatment photograph of FIGURE 18. A pretreatment photograph of FIGURE 19. The initial tracing of the pretreatment the full smile of a patient at the initial evaluation a frontal retracted view of the same dentition tooth arrangement of Figure 18. A retracted view appointment utilizing the Frankfurt horizontal and as Figure 17 utilizing the same alignment guides. allows accurate duplication of the gingival frame. Blue interpupillary midline as alignment grid landmarks. Nearly identical alignment allows both images to lines were added to aid visualization of the existing axial be superimposed for smile design purposes. inclination of the incisors. optical properties, strengthened esthetic with lips pulled out of the way is needed dental midline. The remainder of the treatment modalities can again be offered to assess gingival frame principles and maxillary anterior segment is divided by a broader range of dentists with sup- individual tooth characterization (e.g., with vertical lines that correspond to 22 ported by a larger number of technicians. gingival emergence pattern, maxillary percent, 6 percent, and 2 percent of the In planning for cosmetic restorative tooth proportions, axial inclination grada- total canine-canine width. These width treatment, the clinician must balance tion, polychromatic tooth gradation). relationships reflect the ideal proportions the specific needs of the patient with By utilizing repeatable facial land- of a modified Golden Percentage analysis. the advantages and disadvantages of marks as a guide for camera alignment, The width of the central incisor is each available treatment modality. The multiple images can be captured with divided by 0.75 to determine the height clinician must have a method of com- identical alignment in photography, even needed for a width:height ratio of 75 paring the pretreatment findings with if they are taken for different purposes percent. The calculated height for the cen- the desired outcome to choose the (i.e., full smile versus retracted) or on tral incisor is used to position a gingival alternative on behalf of the patient. different days (i.e., pretreatment versus guideline in harmony with the upper lip post-treatment). It has been suggested reveal and a smile line in harmony with Smile Design that the Frankfurt horizontal and the the curvature of the lower lip. The gingival Specific treatment modalities can interpupillary midline are examples of framework may be drawn as a straight only be considered after a comprehensive convenient, unchanging landmarks that horizontal line, only if the initial photo- evaluation of facial and dental structures can be utilized for consistency in dental graph capture was aligned with the Frank- is performed and the desired outcome photography68 (FIGURE 16). Tracings of furt horizontal landmarks. Mesial axial in- is previsualized.3 Assessment for devel- images with identical alignment can be clination guidelines and embrasure depth oping esthetic treatment plans begins superimposed to allow the simultaneous guides are added in contrasting colors with excellent intraoral photographic evaluation of all esthetic principles, with to complete the framework (FIGURE 20). documentation.4 Different images are or without the lips in place (FIGURES 17-18). Another piece of tracing paper is required to evaluate the full spectrum The initial tracing of the maxillary superimposed over the outline of the of esthetic principles for each patient. teeth, as seen in a retracted view, provides existing teeth and the ideal smile frame- A view that captures the entire head of the basis for evaluating the position of work. Each tooth of the anterior seg- a patient would be required to evaluate teeth at the time of the examination ment is added in its position within the facial balance principles (e.g., interpupil- (FIGURE 19). A second piece of tracing pa- designed tooth arrangement. By conform- lary line, midline, occlusal plane, E-plane, per is placed over the first for the develop- ing to the boundaries and guidelines of nasolabial angle). A view with the lips in ment of a smile design framework that the framework dimensions, the proposed repose is useful to assess the incisal edge incorporates the aforementioned esthetic smile design will simultaneously possess display at rest. A view with a full smile is principles. Vertical lines representing all of the desired dentofacial principles. required to evaluate dentofacial principles frontal height of contour of the maxillary The clinician can then compare the dif- involving the degree of harmony of the canines are drawn to define the maxil- ference between the underlying tracing lips with the underlying dental structures lary canine-canine width. The distance is of the existing tooth arrangement with (e.g., convex smile line, gingival display, divided in half and marked with a third the proposed tooth arrangement of the buccal corridors). Finally, a retracted view vertical line representing the proposed superimposed smile design (FIGURE 21).

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FIGURE 20. A design framework is superimposed FIGURE 21. A proposed smile design is FIGURE 22. A pretreatment retracted view re- over the original tracing. It represents guidelines for developed and superimposed to conform to the veals arrangement deficiencies (including missing anterior tooth proportions, angulations, embrasures, dentofacial principles of the completed framework. lateral incisors) that contribute to a canted smile and gingival emergence as dictated by the canine- Disparities suggest treatment alternatives (e.g., line, inappropriate anterior proportions, embrasure canine width and lip reveal of the individual patient. additional orthodontics, posterior segment crown irregularities, and gingival pattern violations. lengthening, anterior veneers).

Application and Implementation tions remain unchanged (FIGURE 23). An interdisciplinary approach is often Some esthetic dental problems are The dental team must have a method required to achieve all the patient’s related to dental principle violations in to help the patient consider the array expectations.70 The more comprehensive color or contour. Tooth wear, for ex- of available treatment alternatives. the treatment plan, the more inclusive ample, could detract from the proper Beyond the use of photographic im- the application and achievement of appearance of tooth form while excessive ages alone, the creation of a smile design esthetic principles in the delivery of intrinsic chroma might adversely affect offers many powerful and effective com- care for complex cases (FIGURE 25). the polychromatic shade shift within a munication opportunities for the dental If the patient chooses to limit treat- tooth. Often dental principle issues can team during the treatment consultation ment, however, it is essential for the be addressed with conservative treatment process. As the clinician draws the design, clinician to present the predictable options. Occasionally, tooth charac- the patient directly observes the artistic limitations in the results. If a patient with terization difficulties can be addressed ability and expertise of the dentist. This dental malalignment prefers restorative on a limited or even isolated basis. may prove beneficial in enhancing patient treatment alone to achieve the illusion Dentofacial principles violations, confidence or in helping a patient choose of proper alignment, compromises in however, are more complex since tooth from among several possible offices for color, contour, emergence, and symme- arrangement factors are always the cause receiving esthetic care. Beyond merely try may remain unresolved as lingering and since improvement in tooth align- boosting credibility for the dental team, esthetic liabilities. Additionally, patients ment is the logical treatment of choice however, the patient can easily visual- may impair expected treatment results (FIGURE 22). Orthodontic treatment is ize the disparity between the existing by insisting on the utilization of specific often the only treatment alternative that tooth arrangement and that of a design restorative materials. Many patients ultimately can produce an ideal result that conforms to accepted esthetic demand metal-free restorative solutions, in dentofacial relationships.70 With the principles. The smile design allows the and clinicians may be tempted to encour- advent of elective esthetic treatment, dentist to correlate objective clinical age their exclusive use.7 The marketing however, patient expectations regarding findings with the patient’s stated priori- tactics of some restorative material manu- treatment options can be misunderstood ties. At issue is the eventual determina- facturers may inappropriately persuade or even unrealistic. Patients may look tion of a treatment plan that will meet dental consumers to believe that one to restorative treatment modalities to the patient’s subjective expectations. specific material or fabrication technique avoid the traditional alternatives that The doctor and patient can now is applicable and preferable for all clinical would predictably achieve the results collaborate as they assess the feasibility circumstances. Unfortunately, patients they desire.69 While patients may pre- of achieving the proposed goals. With may still hold the clinician responsible fer to explore restorative alternatives the help of the smile design, they can for any restorative failures in spite of with accompanying periodontal crown consider the esthetic problems caused the constraints that they imposed dur- lengthening surgery, continued smile by the dentofacial relationships (FIGURE ing treatment planning. Realizing what principle violations (e.g., in width propor- 24). Periodontal procedures and orth- cannot be accomplished with a specific tions, embrasure gradation, gingival odontic treatment should be considered treatment option is just as important as emergence pattern and symmetry) are as important supplements or even understanding what can be achieved. inevitable if the underlying root posi- replacements to restorative care alone. The smile design process represents

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FIGURE 23. A post-treatment view of the same FIGURE 24. A preprosthetic view of the same FIGURE 25. A post-treatment view of the com- patient as Figure 22. Although restoration contours patient as Figures 17-21. The patient agreed to addi- pleted case for the patient in Figures 17-21 and 24. created the illusion of many esthetic improve- tional orthodontics and posterior crown lengthen- ments, the patient’s refusal of comprehensive ing to position the teeth and gingiva appropriately orthodontic and periodontal treatment resulted in to develop ideal anterior principles of proportion persistent esthetic violations. and alignment. a tool to overcome these obstacles. In the restorative material that specifically REFERENCES addition to objectively identifying the meets those needs.3 With a treatment 1. Ahmad I, Geometric considerations in anterior dental esthet- ics: Restorative principles. Pract Periodont Aesthet Dent number of teeth that present esthetic planning paradigm driven by design, 10(7):813-22, 1998. distraction, it can indicate appropriate a dentist aptly may recommend and 2. Chiche GJ, Pinault A, Esthetics of anterior fixed prosthodon- preparation design strategies that in prescribe different restorative materials tics. Chicago, Quintessence Publishing Co., pp 13-73, 1994. 3. McLaren EA, Rifkin R, Macroesthetics: Facial and dentofa- turn require specific material selection on a tooth-by-tooth basis. The dentist cial analysis. J Calif Dent Assoc 30(11):839-46, 2002. recommendations. If tooth alignment is must then select a laboratory with the 4. Arnett GW, Bergman RT, Facial keys to orthodontic diag- already ideal, facial surface preparation capability and experience to effectively nosis and treatment planning part II. Am J Ortho Dent Facial Orthop 103(5):395-411, May 1993. alone with maximum enamel reten- utilize the required material systems. 5. Rufenacht CR, Fundamentals of Esthetics. Chicago, Quin- tion may suffice. In that circumstance, Precise dimensional changes for peri- tessence Publishing Co., 33-66, 1990. direct resin restorations or powder-liquid odontal, orthodontic, and laboratory pro- 6. Rufenacht CR, Fundamentals of Esthetics. Chicago, Quin- tessence Publishing Co., 67-134, 1990. ceramic veneers allow the most conserva- cedures can be quantified, illustrated, and 7. Goodkind RJ, Schwabacher WB, Use of fiber optic color- tive treatment solution. If anterior width transferred to models, guides, and resto- imeter for in vivo measurements of 2,830 anterior teeth. J proportions are to be altered, additional rations. The prospect for predictable, coor- Prosthetic Dent 58:535-42, 1987. 8. Ubassy G, Shape and color, Chicago, Quintessence Publish- interproximal preparation will be re- dinated treatment result is thus increased. ing Co., 197-210, 1993. quired, and significantly more enamel 9. Ubassy G, Shape and color, Chicago, Quintessence Publish- will be removed. In the case of traumatic Conclusion ing Co., 25-30, 1993. 10. Snow SR, Esthetic smile analysis of maxillary anterior fractures, significant enamel may al- The contemporary photographic tooth width: The golden percentage. J Esthet Dent 11(4):177-84, ready be missing. In the face of these process is revolutionizing the way clini- 1999. increased restorative demands, pressed cians diagnose, treat, and communicate 11. Snow SR, Application of the golden percentage in smile de- sign and esthetic treatment success. Contemp Esth 10(9):30-7, ceramic systems should be considered as a with patients and colleagues. Smile September 2006. strengthened partial coverage alternative. design techniques expand the use of 12. Morley J, Eubank J, Macroesthetic elements of smile design Although pressed ceramics allow par- photography to analyze existing esthetic J Amer Dent Assoc 132(1):39-45, January 2001. 13. Bengel W, Mastering Digital Dental Photography, 2nd ed., tial coverage preparation design, occlusal problems and communicate possible Quintessence International Co., United Kingdom, 75-88, 2006. function, and resulting flexural forces treatment alternatives. Treatment ac- 14. Snow SR, Dental photography systems: Required features must be respected. Parafunction, abfrac- ceptance occurs when patients perceive for equipment selection. Compend 26(5):309-21, 2005. 15. McLaren EA, Terry DA, Photography in dentistry. J Calif tion, sclerotic dentin are all complicating the recommended treatment will resolve Dent Assoc 29(10):735-42, 2001. factors. To establish anterior guidance, current and future concerns for a fee 16. Goldstein MB, Young R, Bergmann R, Digital photography. increase strength, and enhance predict- that is commensurate with the benefits Compend 24(4):260-73, 2003. 17. Goldstein MB, Digital photography in your dental practice: ability, full coverage preparations and they gain. Patient satisfaction is achieved The why’s, how’s, and wherefore’s. Dent Today 22(4):98-101, ceramic modalities with internal strength- when the clinician meets or exceeds the April 2003. ened cores may be indicated. Rather than patient’s expectations. It is only through 18. Christensen GJ, Important clinical uses for digital photog- raphy. J Am Dent Assoc 136(1):77-9, 2005. inappropriately selecting a restorative a balance in objective diagnosis, effec- 19. Wander P, Gordon P, Specific applications of dental photog- material and then attempting to apply it tive communication, and evidence-based raphy. Br Dent J 162(10):393-403, 1987. to a patient’s needs, the clinician can use planning that proper recommendations 20. Christensen GJ, Informing patients about treatment alternatives. J Am Dent Assoc 130(5):730-2, 1999. the smile design to appropriately assess can be made for the delivery of excel- 21. Christensen GJ, Elective versus mandatory dentistry. J Am the patient’s needs first and then select lence in cosmetic dental treatment. Dent Assoc 131(10):1496-8, 2000.

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22. Terry DA, Moreno C, et al, The importance of laboratory 46. Rosenstiel SF, Land MF, et al, Chapter 24, Metal ceramic 88:4-9, 2002. communication in modern dental practice: Stone model with- restorations in Contemporary Fixed Prosthodontics, 4th ed. St 67. Heffernan MJ, Aquilino SA, et al, Relative translucency of out faces. Pract Periodontics Aesthet Dent 11(9):1125-32, 1999. Louis, Mosby Elsevier, 2006. six all-ceramic systems. Part II: Core and veneer materials. J 23. Touati B, Miara P, Nathanson D, Esthetic dentistry ceramic 47. Tooth preparations in fundamentals of fixed prosthodon- Prosthet Dent 88:10-15, 2002. restorations, London, UK, Martin Dunitz, 124-30, 1999. tics, 3rd ed. Chicago, Quintessence Books, 1997. 68. Snow SR, Repeatable alignment — Part II: Consistent 24. Elter A, Caniklioglu B, et al, The reliability of digital 48. Neiva G, Yaman P, et al, Resistance to fracture of three photographic alignment accuracy. Pract Proced Aesthet Dent cameras for color selection. Int J Prosthodont 18(5):438-40, all-ceramic systems. J Esthet Dent 10(2):60-6, 1998. 15(7):551-7, August 2003. September-October 2005. 49. Stappert CF, Guess PC, et al, All-ceramic partial coverage 69. Spear FM, The esthetic correction of anterior dental 25. Dunn J, Hutson B, Levato C, Photographic imaging for premolar restorations. Cavity preparation design, reliability malalignment conventional versus instant (restorative) ortho- esthetic restorative dentistry. Compend 20(8):766-78, 1999. and fracture resistance after fatigue.Am J Dent 18(4):275-80, dontics. J Calif Dent Assoc 32(2):133-41, February 2004. 26. Zyman P, Etienne JM, Recording and communicating shade 2005. 70. Spear FM, Kokich VG, Mathews DP, Interdisciplinary with digital photography: Concepts and considerations. Pract 50. Guazzato M, Albarky M, et al, Strength, fracture toughness management of anterior dental esthetics. J Am Dent Assoc Proced Aesthet Dent 14(1):49-57, 2002. and microstructure of a selection of all-ceramic materials. 137(2):160-9, February 2006. 27. Spear FM, Photography as a laboratory-communication Part I. Pressable and alumina glass-infiltrated ceramics. Dent 71. Spear FM, The metal-free practice: Myth? Reality? Desir- tool. Dent Econ 84(5):90-1, May 1994. Mater 20(5):441-8, 2004. able goal? J Esthet Restor Dent 13(1):59-67, 2001. 28. Small BW, Location of incisal edge position for esthetic 51. Anusavice KJ, Chapter 21, Dental Ceramics in Anusavice restorative dentistry. Gen Dent 48(4):396-7, July-August 2000. KJ, Phillips’ Science of Dental Materials, 11th ed. St. Louis, W.B. 29. Spear FM, The maxillary central incisal edge: A key to Saunders Co., 2003. TO REQUEST A PRINTED COPY OF THIS ARTICLE, PLEASE esthetic and functional treatment planning. Compend Contin 52. Goldin EB, Boyd NW, et al, Marginal fit of leucite-glass CONTACT Stephen R. Snow, DDS, Snow Dental Care, 909 San Educ Dent 20(6):512-6, June 1999. pressable ceramic restorations and ceramic-pressed-to-metal Ramon Valley Blvd., #216, Danville, CA 94526. 30. Clark JR, Digital photography. J Esthet Restor Dent restorations. J Prosthet Dent 93(2):143-7, February 2005. 16(3):147-8, 2004. 53. Malament KA, Grossman DG, The cast glass-ceramic 31. Robbins JW, Evidence-based dentistry: What is it and what restoration. J Prosthet Dent 57(6):674-83, 1987. does it have to do with practice? Anecdote versus data — a 54. Helvey GA, Fabrication of aesthetic, pressed, porcelain- case for evidence-based decision-making. Quintessence Int fused-to-metal restorations. Pract Proced Aesthet Dent 29(12):796-9, 1998. 14(6):487-92, 2002. 32. Magne P, Composite resins and bonded porcelain: The 55. Sutton AF, McCord JF, Variations in tooth preparations for postamalgam era? J Calif Dent Assoc 34(2):135-47, February resin-bonded all-ceramic crowns in general dental practice. 2006. Brit Dent J 191(120):677-81, 2001. 33. Murchison DF, Roeters J, et al, Chapter 9: Direct anterior 56. Harris EF, Hicks JD, A radiographic assessment of restorations, in Summitt JB, Robbins JW, et al, Fundamentals enamel thickness in human maxillary incisors. Arch Oral Biol of Operative Dentistry — A Contemporary Approach, 3rd ed. 43(10):825-31, 1998. Chicago, Quintessence Publishing Co., Inc., 2006. 57. Atsu SS, Aka PS, et al, Age-related changes in tooth 34. Simonsen RJ, Calamia JR, Tensile strength of etched enamel as measured by electron microscopy: Implications porcelain. J Dent Research 62:297, 1983. for porcelain laminate veneers. J Prosthet Dent 94(4):336-41, 35. Lopes GC, Thys DG, et al, Enamel acid etching: A review. 2005. Compen Cont Ed Dent 28(1):18-25, 2007. 58. Magne P, Douglas WH, Cumulative effects of successive 36. Warden D, The dentist-laboratory relationship: A system restorative procedures on anterior crown flexure: Intact for success. J Am Coll Dent 69(1):12-4, 2002. versus veneered incisors. Quintessence Int 31(1):5-18, January 37. Lehner CR, Mannchen R, et al, Variable reduced metal 2000. support for collarless metal ceramic crowns: A new model for 59. Gonzales-Lopez S, DeHaro-Gasquet F, et al, Effect of strength evaluation. Int J Prosthodont 8(4):337-45, 1995. restorative procedures and occlusal loading on cuspal deflec- 38. Magne P, Magne M, Treatment of extended anterior crown tion. Oper Dent 31(1):33-8, 2006. fractures using Type IIIA bonded porcelain restorations. J Calif 60. Freaedani M, Redemagni M, An 11-year clinical evaluation Dent Assoc 33(5):387-96, May 2005. of leucite-reinforced glass-ceramic crowns: A retrospective 39. Troedson M, Derand T, Effect of margin design, cement study. Quintessence Int 33:503-10, 2002. polymerization, and angle of loading on stress in porcelain 61. Sorensen JA, Choi C, et al, IPS Empress crown system: veneers. J Prosthet Dent 82(5):518-24, 1999. Three-year clinical trial results. J Calif Dent Assoc 26(2):130-6, 40. Peumans M, De Munck J, et al, A prospective 10-year clini- 1998. cal trial of porcelain veneers. J Adhes Dent 6(1):65-76, 2004. 62. Kramer N, Frankenberger R, Clinical performance of 41. Donovan TE, Longevity of the tooth/restoration complex: A bonded leucite-reinforced glass-ceramic inlays and onlays review. J Calif Dent Assoc 34(2):122-8, February 2006. after eight years.Dent Mater 21:262-71, 2005. 42. Litonjua LA, Andreana S, et al, Tooth wear: Attrition, ero- 63. Raigrodski AJ, Clinical and laboratory considerations for sion, and abrasion. Quintessence Int 34(6):435-46, 2003. the use of CAD/CAM Y-TZP-based restorations. Pract Proced 43. Walton TR, A 10-year longitudinal study of fixed prosth- Aesthet Dent 15(6):469-76, 2003. odontics: Clinical characteristics and outcome of single-unit 64. Picconi C, Maccauro G, Zirconia as a ceramic material. metal-ceramic crowns. Int J Prosthodont 12:519-26, 1999. Biomater 20:1-25, 1999. 44. Brune D, Metal release from dental biomaterials. Biomate- 65. Luthardt RG, Holzhuter M, et al, Reliability and properties rials 7(3):163-75, May 1986. of ground Y-TZP-zirconia ceramics. J Dent Res 81(7):487-91, 45. Donovan TE, Chee WW, Cervical margin design with July 2002. contemporary esthetic restorations. Dent Clin North Am 48(2): 66. Heffernan MJ, Aquilino SA, et al, Relative translucency of vi, 417-31, 2004. six all-ceramic systems. Part I: Core materials. J Prosthet Dent

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Clinical Crown Lengthening in the Esthetic Zone PAULO M. CAMARGO, DDS, MS; PHILIP R. MELNICK, DMD; AND LUCIANO M. CAMARGO, DDS, MSED

ABSTRACT Periodontal surgical procedures consisting of gingival flaps and osseous recontouring are indicated for crown lengthening of several contiguous teeth in the esthetic zone; both in cases where restorations are required and in cases where no restorations are planned, such as in patients with excessive gingival display due to altered passive eruption. Forced tooth eruption via orthodontic extrusion is the technique of choice when clinical crown lengthening is necessary on isolated teeth in the esthetic zone.

AUTHORS linical crown lengthening biologic width to be re-established at a

Paulo M. Camargo, DDS, Philip R. Melnick, DMD, is refers to procedures designed more apical level, allowing for proper MS, is an associate a lecturer in periodontics, to increase the extent of placement of the restorative margin. professor of periodontics, UCLA School of Dentistry, supragingival tooth structure However, when crown lengthening University of California, and in private practice in for restorative or esthetic becomes necessary in the esthetic zone Los Angeles, School of Cerritos, Calif. purposes. Clinicians often encounter — particularly the upper anterior seg- Dentistry, and in private C practice in Los Angeles. Luciano M. Camargo, the need for crown lengthening in the ment — the clinician must be cautious DDS, MSED, is an adjunct practice of dentistry (TABLE 1) and have in making the appropriate diagnosis and professor of prosthodon- to make treatment decisions taking in selecting a treatment technique that tics, University of Paraná into consideration how to best address takes into consideration not only the School of Dentistry, and the biological, functional, and esthetic functional, biological, and restorative in private practice in Curitiba, Brazil. requirements of each particular case. needs of the tooth or teeth in ques- Often, the need for crown length- tion, but that also results in acceptable ening is dictated by restorative dental esthetics. While conventional periodontal procedures requiring margin placement surgery consisting of flaps and osseous in close proximity to the alveolar bone recontouring are applicable, technical crest, violating the supracrestal area of modifications are often required to ensure the periodontal attachment regarded a satisfactory esthetic outcome. Also, as the biologic width.2 In the posterior the clinician must be able to recognize segments, the esthetic consequences the specific situations when orthodon- of crown lengthening are of lesser tic extrusion rather than periodontal concern. In these cases, periodontal surgery is the preferred treatment. surgery consisting of gingival flaps and The need for clinical crown length- osseous resective surgery is the tech- ening in the esthetic zone may not be nique of choice to create space for the related to restorative dental procedures.

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TABLE 1 FIGURE 1. Clinical and Indications for clinical crown schematic representation lengthening. of a fully erupted tooth in the absence of attachment ■ Subgingival fracture loss. Notice that the space between the alveolar crest ■ Subgingival caries and the cementoenamel junction is occupied by soft tissue directly ■ Endodontic/pin/post perforation attached to the tooth surface, which is referred ■ Root resorption to as the biologic width.

■ Inadequate axial height for restoration retention

■ Unequal gingival levels

■ Esthetically short crowns due to tooth wear

■ Altered passive eruption

There are patients who present with excessive gingival display upon smil- ing (also referred to as “gummy smile”) and the reduction of this excessive display is desirable for the purpose of improving esthetics. While there are FIGURE 2. Violation of the biologic width: FIGURE 3. Case shown in Figure 2 following several possible etiologies involved in Restoration margins on teeth Nos. 8 and 9 were elevation of a buccal flap. Notice the minimum placed 4 mm subgingivally in close proximity to the distance between the restoration margin and the excessive display of the gingival tis- alveolar bone. Notice the inflammatory changes on crest of the alveolar bone. sues upon smiling, cases in which teeth the marginal gingiva. present with incomplete eruption (also referred to as altered passive eruption) along the tooth surface on a fully erupted Therefore, the physiologic location are most amenable to successful treat- tooth in the absence of attachment loss. of the biologic width can vary with age, ment with surgical crown lengthening. Radiographically, it has been shown tooth migration due to loss of arch or that the average distance between the occlusal integrity, or orthodontic treat- Biologic Width: Definition, Clinical Rel- cementoenamel junction and the bone ment. Taken all together, it is obvious evance, and Violation Consequences crest varies between 0.4 mm (in which there is significant variation in the data The concept of the biologic width was case the junctional epithelium is at- attempting to document the physiologic first originated by research conducted tached to enamel) and .9 mm (in which position of the alveolar bone crest in by Gargiulo, Wentz, and Orban where case the junctional epithelium is at- relation to the CEJ and, for the purpose the distance between the apical end of tached to cementum) in one study and of discussion in this manuscript; it will the gingival sulcus and the crest of the between 0.5 mm and 2 mm in another be assumed the marginal crest of the alveolar bone was measured on sev- study.4,5 The average discrepancy between alveolar bone is physiologically located eral cadaver specimens.2,3 In areas that radiographic data and clinical data on approximately 2 mm apical to the CEJ. present with periodontal health, that the actual distance between the CEJ and The coronal end of the junctional epithe- distance, now regarded as the biologic the bone crest is 0.46 mm, suggesting a lium is therefore coincident with the CEJ width, was reported to be an average of reasonable accuracy of the radiographic (FIGURE 1) on a fully erupted tooth where 2.04 mm, where approximately 0.97 mm data.6 It is also likely that the location no loss of attachment has occurred. is occupied by the junctional epithelium of the biologic width migrates apically With respect to the biologic width and .07 mm is occupied by connective along the tooth surface throughout life, measurement, it should also be consid- tissue attachment to the root surface. even in the absence of attachment due to ered that 2.04 mm was an average for There is a reported wide range of continuous eruption of teeth, which hap- the study population and substantial possible locations of the biologic width pens as a consequence of occlusal wear.3 variations occur among individuals

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FIGURE 4. Bone resorption in form of a vertical FIGURE 5. In a well-balanced smile, there is limited FIGURE 6. Example of excessive gingival display defect that occurred originally as a response to a vi- display of the upper gingival tissues. upon smiling. A “gummy smile” is a cause of esthetic olation of the biologic width by the improper place- complaints by patients. ment of a restoration margin. Even though there is now enough root surface area for a new biologic width to develop, the site is susceptible to plaque ries proposed is that there is insufficient ative dentistry. While the actual cause for accumulation and the development of inflammatory periodontal diseases caused by bacteria. space for a “normal” length junctional the development of chronic inflammation epithelium to develop; the junctional in areas where the biologic width is violat- epithelium is short, weak, and does not ed may not be precisely understood, the (±30 percent).3 It has been shown that exert an effective sealing effect of the consequences of its violation in inducing the biologic width is approximately 2 dentogingival unit.9 Moreover, the area is inflammatory changes to the periodon- mm in 85 percent of the population.7 In easily damaged by mechanical oral hygiene tium are well documented. Therefore, it is approximately 3 percent of the popula- practices, and chronic inflammation essential the interaction between restor- tion, that distance exceeds 2 mm while persists or is easily induced. Others believe ative procedures and the biologic width the same distance is less than 2 mm in a deeply placed subgingival restorative be understood, and properly addressed 2 percent of the individuals examined.7 margin, close to the alveolar bone crest, by the clinician when treating patients. Therefore, it should be remembered that impairs proper plaque control promoting the only precise technique to measure inflammatory changes not conductive to The Gingival Scaffold as an Integral the biologic width on a particular patient a healthy periodontal environment.0 Component of a Well-balanced Smile is to perform bone sounding under local There is still a third theory regard- The upper anterior segment is by anesthesia in a periodontally healthy site. ing the consequences of biologic width far the area of the dentition with the The commonly used 2 mm biologic width violation by the apical placement of most esthetic implications. As such, rule can be misleading if used empiri- restorative margins. It is argued that the clinical situations with esthetic relevance cally in the treatment of all cases. biologic width, while violated at first, described in this paper will primarily Violation of the biologic width is a will naturally redevelop in a more apical refer to the upper anterior segment. common occurrence in the practice of position at the expense of further bone Books have been dedicated to the de- restorative dentistry. A familiar clinical resorption that occurs following prepara- scription of all elements involved in an es- situation in which the biologic width tion of the tooth and establishment of a thetically pleasant, well-balanced smile.,2 can be violated is by the placement of a restorative margin.7 Interestingly, these While a detailed discussion about smile deep subgingival restoration. The need effects of such bone resorption are often esthetics escapes the scope of this article, to establish a subgingival restorative closely related to the patient’s periodon- a brief description of the role played by margin can be dictated by caries, tooth tal biotype. Chronic inflammation in the position and symmetry of the gingival fracture, external root resorption, or the a thin biotype may result in bone loss scaffold in the overall context of an es- need to increase axial height of a tooth and gingival recession. In a thick bio- thetically well-balanced smile is pertinent preparation for retention purposes. type, such bone resorption might occur to the topics described in this manuscript. If the apical margin of the restorative in the form of a vertical osseous defect In general, it is commonly accepted preparation is placed within the biologic (FIGURE 4) that will lead to difficulties in that up to 2 mm of gingival tissue be width (i.e., too close to the bone), a zone of plaque removal by the patient and the displayed upon a full smile3 (FIGURE 5). chronic inflammation is likely to develop8 development of plaque-induced inflam- While display of less than 2 mm of gingi- (FIGURES 2-3). The precise mechanism for matory conditions of the periodontium. val tissue might occasionally constitute an chronic inflammation to develop in a In summary, there is no clinically or esthetic concern for patients, the display scenario where the restorative margin is scientifically sound justification to ignore of more than 2 mm of gingival tissue placed within the biologic width area is the biologic width as an anatomical and (FIGURE 6) is often a reason for patients not fully agreed upon. One of the theo- functional entity in the practice of restor- to seek treatment with the objective of

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FIGURE 7. Ideal position of the gingival scaf- FIGURE 8. Anterior view of a case in which the FIGURE 9. Anterior view of a case in which the fold on the upper anterior segment. Notice the gingival line is present at the same apico-coronal gingival margin position on the upper left lateral gingival line position is more coronal on the lateral level on the central and lateral incisors and the ca- incisor is more apical than on the central incisors. incisors as compared to the central incisors and nines. This gingival profile, even though not ideal, This gingival profile is not acceptable from the canines. does not constitute a significant violation of the esthetic standpoint. esthetic parameters of a well-balanced smile. decreasing gingival display. The etiolo- sures. Treatment that results in a less scal- cases in the esthetic zone might be neces- gies of excessive gingival display and its loped, flatter gingival margin will often re- sary on several contiguous teeth (i.e., treatment options are described later in sult in shorter interdental papilla and the the whole upper anterior segment) or on this article. The presence of the gingival opening of the embrasure spaces (i.e., gen- isolated teeth, and the clinical manage- margin in a position that is too coronal eration of “black triangles”). This consti- ment of those two case types also differ is one of the etiologies that may result in tutes an easily observable esthetic breach substantially. A treatment decision tree excessive gingival display upon smiling. and may require closure by restorative for teeth requiring crown lengthening in It is also accepted that the position of procedures with long contact surfaces. the esthetic zone is presented on TABLE 2. the gingival margin on upper canines and The clinical relevance of various central incisors is ideally parallel to the magnitudes of less-than-ideal position Crown Lengthening in Restorative inter-pupillary line. However, the gingival and symmetry of the gingival scaffold Cases: Multiple Contiguous Teeth margin position on upper lateral incisors in the esthetic zone has been evaluated The need for clinical crown lengthen- is often located slightly coronal to the through research.4 Despite the fact the ing of the upper anterior segment prior gingival line position on upper central patient’s observational capabilities ap- to placement of restorations can be a incisors and canines (FIGURE 7). While a pear to be fairly tolerant to small gingival result of caries, external root resorption, slight deviation from the parallel position discrepancies present in the esthetic zone, tooth fracture, or the need to increase of the gingival line to the inter-pupillary basic esthetic principles should be fol- the axial height of teeth for restoration line does not usually constitute a notice- lowed in treatment procedures including retentive purposes. In any of these situ- able esthetic compromise (FIGURE 8), crown lengthening because noticeable ations, tooth preparation to the desired having the gingival line on upper lateral thresholds can be clearly exceeded and level in the apical direction may result incisors positioned apical to the gingival result in unacceptable treatment end- in violation of the biologic width. line position on upper central incisors points from the esthetic standpoint. The basic concept of crown lengthen- and canines is considered less acceptable ing for restorative ease is to surgically from the esthetic standpoint (FIGURE 9). Crown Lengthening in the Esthetic Zone “move” the bone crest to a more apical The position of the gingival mar- Clinical situations in which crown position, providing for sufficient coronal gin should be symmetric on both sides lengthening is indicated in the esthetic tooth structure for restoration, while of the esthetic zone. Discrepancies in zone can be classified into two basic types: allowing space for re-establishment of a the position of the gingival margin on restorative cases, where placement of new physiologic dentogingival dimension different elements of the same tooth restorations will follow the execution and (biologic width). It should be remembered group (i.e., upper right and left central healing of the crown lengthening proce- that the distance between the gingival incisors) are easily caught by causal dure; and nonrestorative cases where no margin and the crest of the bone is ge- observation and should not be over- restorations of the teeth being lengthened netically determined.3 Therefore, the soft looked in analyzing and performing are planned. The treatment approaches tissue regrows to its genetically prede- dental treatment in the esthetic zone. utilized in restorative and nonrestor- termined height in relation to the bone, Finally, the ideal gingival contour is ative cases differ significantly, and for whether or not bone profile has been scalloped in shape and soft tissue papillae that reason will be discussed separately. modified in the crown lengthening pro- fully occupy the interproximal embra- Further, crown lengthening in restorative cedure. On the other hand, the position

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TABLE 2

Treatment decision tree for a tooth or teeth requiring clinical crown lengthening in the esthetic zone.

Tooth or teeth in need

of clinical X crown lengthening X

Nonrestorative case

Restorative case (excessive gingival X X X X display)L

Isolated Multiple contiguous Maxillary vertical Short/hyper Altered passive

tooth teeth excess mobile lip eruption L L L L L

Orthodontic Rapid orthodontic Periodontal Periodontal intrusion with Surgical lip

extrusion/ surgery flaps and surgery flaps and

possible ortho- repositioning fiberotomy osseous surgery osseous surgery X gnathic surgery

If coronal move- ment of the gingival

margin occurs

localized surgical procedureX

Final restoration(s) of the gingival margin in relation to the crowns of the teeth being treated. Because tion of the final position of the restorative tooth surface is dictated by the position lengthening through a periodontal surgi- margins is useful in guiding the surgeon of the alveolar bone. Soft tissue rebound cal procedure increases the apico-coronal as to the extent of osseous recontour- is therefore determined by the position of crown dimension, the final restorations ing required. Also, the execution of the the underlying bone and is independent may (if esthetic, phonetic, and oc- surgical procedure is facilitated by the from the restorative treatment performed. clusal demands permit) require incisal removal of the temporary restorations. Treatment planning of restorative reduction in order to maintain proper The technique of choice for crown cases requiring crown lengthening in apico-coronal/mesiodistal proportion. lengthening of multiple contiguous teeth the esthetic zone should be initiated Ideally, prior to the crown lengthen- in the upper anterior segment where res- by a diagnostic wax-up mimicking the ing procedure, preliminary preparation torations will be delivered is the apically future goals to be achieved by the crown of the teeth to be treated should be positioned flap combined with resective lengthening procedure and the size and conducted by the restorative dentist osseous surgery (FIGURES 10A-B). The surgi- shape of the final restorations. From the followed by placement of temporary cal procedure includes the elevation of a esthetic standpoint, attention should be restorations. The margins of the tem- buccal flap combined or not with a palatal paid to the proposed final position of the porary restorations should be placed in flap, depending on the need for crown incisal edge (tooth exposure, phonetics), healthy tooth structure and as close to lengthening on the palatal and interproxi- crown length, as well as to the apico-coro- the position of the final restoration as mal aspects of the teeth being treated. In nal/mesiodistal proportion of the clinical possible. Having a preliminary delinea- cases where both a buccal and a palatal

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FIGURE 10A. Osseous profile of teeth Nos. 7 FIGURE 10B. Osseous resection was FIGURE 11. Clinical crown lengthening of an iso- through 10 following flap reflection and soft tissue performed around teeth Nos. 7 through 10 as to lated tooth in the upper anterior segment results degranulation. Notice minimal exposure of tooth expose a minimum of 3 mm or tooth structure. in gingival margin asymmetry and unacceptable structure coronal of the alveolar bone level. esthetic results.

flap are elevated, degranulation of the formed with a high-speed handpiece under the restorative margin during the final interproximal spaces is performed. Initial copious water spray. The rear-exhaust preparation of the teeth. For instance, if incisions on the buccal aspect of the teeth handpiece has been recommended in order the biologic width for a particular case to be lengthened can be apical to the to minimize the possibility of air embo- is 2 mm, the clinician should create a gingival margin and scalloped in shape lism. Osteoplasty refers to the removal of space ≥ 3 mm between the temporary if there is an abundance of keratinized nonsupporting bone and is the first step in restoration margin and the crest bone so tissue. The initial incision may be placed the osseous recontouring process.5 Bucco- that a “margin of safety” is built into the close to or in the gingival sulcus in cases lingual reduction of the alveolar housing procedure in case the restoration margin where the dimensions of the keratinized is achieved with the use of round burs and needs to placed in a more apical position. tissue are limited (<3 mm). In designing is more pronounced in the interproximal Teeth with extensive coronal damage, the flap, an attempt should made to create areas than on the direct buccal and lingual such as those in which endodontic treat- surgical papillae that are relatively thick surfaces of the teeth. An ostectomy is ment have been performed and a core and long, so that a well-scalloped gingi- the removal of supporting bone and it has been placed, may require a greater val line with the presence of full papillae can be performed with the use of end- extent of tooth structure exposure in develops following healing. This reduces cutting burs and/or osseous chisels.5 crown lengthening procedures. Therefore, the need to fabricate final restorations The amount of ostectomy to be a greater amount of ostectomy may be that, in order to close wide postoperative performed depends upon the future necessary on such teeth. That require- interproximal spaces, have long con- position of the restoration margins and ment exists because a minimum of  to 2 tact surfaces and tend to be excessively the biologic width for that particular mm of natural tooth structure coronal to rectangular rather than triangular in patient. As stated before, the most precise the preparation line is recommended for shape. The palatal flap employs scalloped technique to determine the biologic width the restoration to exert a ferrule effect on incisions combined with thick and long for a particular patient is to perform the tooth, which aids in retention and re- surgical papillae, similar to the buccal flap. transgingival bone sounding under local ducing the risk of a future root fracture.6 The buccal flap should be reflected anesthesia in periodontally healthy areas. Another important point in the osse- apical to the mucogingival junction as to It is important to perform bone sound- ous recontouring process is the establish- expose the alveolar bone where recon- ing on straight (buccal and/or lingual) ment of positive osseous architecture with touring is necessary and also to allow for and interproximal areas, as measure- the resective procedure.7 Often, the need flap mobility. The palatal flap should be ments may differ. This data can be used to for ostectomy is more pronounced in the reflected sufficiently to allow for ad- determine the space that will be required interproximal areas than on the direct buc- equate access for osseous recontouring. for the reformation of the supracrestal cal and lingual areas, and that interproxi- All gingival tissues left in contact with tissues. As previously noted, that is mal osseous resection should be accom- the teeth and bone following elevation anticipated to be in the magnitude of 2 panied by ostectomy on the direct buccal of the flaps should be removed with mm. An ostectomy should be performed and/or lingual surfaces so that the direct the use of curettes and sonic/ultrasonic as to create a distance between the buccal and lingual bone levels are more devices. Scaling and root planing of the restoration margin and the alveolar crest apical than the interproximal levels of the teeth involved in the surgery should that is slightly ( mm) greater than the alveolar bone. The average facial–inter- also be performed if clinical inspec- premeasured dimension of the biologic proximal bone scallop of a maxillary central tion reveals the presence of calculus. width for that patient in order to ac- incisor is approximately 3 mm. Negative Osseous recontouring is usually per- count for further apical displacement of osseous architecture (i.e., the buccal and/or

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FIGURE 12A. Clinical view of tooth No. 9, which presented with external root resorption on its mesial aspect and required clinical crown lengthening prior FIGURE 12B. Radiographic view of FIGURE 12C. Radiographic view of to restoration. (Courtesy of Dr. Bruce J. Crispin, tooth No. 9 shown on Figure 12a. Notice tooth No. 9 shown on Figure 12a three Tarzana, Calif.) the proximity of the apical end of the weeks after forced eruption through resorption area and the interproximal conventional orthodontics. Compare the bone crest. relationship between the resorption area and the interproximal bone crest prior to the extrusion (Figure 12b) and after the extrusion.

contact with bone. The new intermediate finish line should be no closer than 4 mm from osseous crest to provide adequate space for healing without encroachment on the newly forming biologic width. Once soft tissue maturation is complete FIGURE 12D. Clinical view of the upper anterior segment of the case first shown on Figure 12a after FIGURE 12E. Clinical view of the final restora- (six to 2 months postoperatively) the completion of the orthodontic extrusion and prior tions on the case first shown on Figure 12a. final preparation can be accomplished, to the delivery of the final restoration. Observe also terminating 0.5 mm intracrevicularly.7 the smaller diameter of the root of tooth No. 9 at the gingival line level as compared to that of tooth No. located supragingival, if further gingival The gingivectomy technique can only 8; the restorative correction of this discrepancy can recession occurs as a result of healing. be utilized for crown lengthening pur- be challenging. Rosenberg has suggested a six-month poses in the esthetic zone in situations wait between the surgical appointment where there is horizontal bone loss and/or lingual bone being more apical than the and the final preparation and impression- increased soft tissue depth, and adequate interproximal bone) is likely to lead to making of the teeth.8 Pontoriero and keratinized gingiva. Treatment of such interproximal periodontal “pocketing” Carnevale studied the final position of cases with the gingivectomy technique following healing of the surgical procedure. the gingival margin following osseous serves the dual purpose of eliminating Flap suturing is performed as to resection in crown lengthening proce- excessive supracrestal tissue and elongat- secure the soft tissue in intimate contact dures and noticed that changes can ing clinical crowns. However, any case in with the crest of the bone and the newly occur up to 2 months after surgery.9 If which osseous recontouring is required exposed root. The temporary restorations esthetics becomes a problem during the to achieve crown lengthening cannot be are cemented and the use of periodontal healing period because of supragingival adequately treated by the gingivectomy dressing is optional. Sutures are removed temporary restoration margins and procedure. Removal of the supracrestal at the end of the first operative week coincident root exposure, an intermediate soft tissues alone will simply result in a when mechanical oral hygiene is initiated. preparation step and temporary restora- regrowth of the predetermined biologic An important aspect of the healing tion relining can be performed prior to dimension, with no net gain in crown of surgical crown lengthening proce- the final preparation and impression- length. The risk is that the illusion of dures is related to the length of the time making appointment. This intermediate adequate crown length will prompt early period between the surgical procedure step should not however be performed for tooth restoration, but now in close prox- and the final preparation and impres- at least six weeks following the surgical imity to bone crest. The inevitable refor- sion-making of the teeth. Of direct procedure to allow for early healing of the mation of the supracrestal gingival tissue clinical importance is the stability of the dentogingival complex and prevent the complex results in a situation to be avoid- postoperative position of the gingival inadvertent dislodgement of foreign ed at the outset; a deep subgingival restor- margin. Premature final tooth prepara- bodies such as restorative materials and ative margin in close proximity to bone tion may lead to final restorative margins cement under the gingival tissues and in crest and infringement of biologic width.

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FIGURE 13A. Clinical view of tooth No. 11 after FIGURE 13B. Forced tooth eruption was conducted FIGURE 13C. Clinical view of tooth No. 11 first caries removal showing violation of the biologic utilizing a metal wire within the temporary restoration shown on Figure 13a at the time of its final prepara- width on the mesial aspect. as anchorage for an orthodontic elastic also attached tion and impression-making, 12 weeks after the to an intra-radicular post. active phase of the orthodontic extrusion was completed. Notice the excellent gingival health on the mesial aspect of tooth No. 11 with no violation of the biologic width.

Forced tooth eruption can be per- formed via conventional fixed orthodon- tic appliances (FIGURES 12A-E), utilizing temporary restorations as anchorage for the orthodontic movement (FIGURES 13A-C) or by fabricating a device similar to the FIGURE 14A. Clinical view of tooth No. FIGURE 14B. A device resembling the frame 4, which required clinical crown lengthening of a removable partial denture was fabricated. framework of a removable partial denture due to a subgingival fracture. If treated with a The device sat passively on the teeth adjacent that sits passively on adjacent teeth, surgical approach, the crown margin on tooth to tooth No. 4 and served as anchorage for to which an orthodontic elastic can be No. 5 would become supragingival and pose an orthodontic elastic also attached to an FIGURES 14A-D an esthetic concern. Forced tooth eruption intraradicular post. activated every other day ( ). of tooth No. 4 was the treatment of choice. In order to prevent the coronal (Courtesy of Dr. John B. Avera, Aptos, Calif.) movement of the gingival tissue and the alveolar bone during the course of the orthodontic extrusion, supracrestal fiberotomies have been suggested.2 Under local anesthesia, severing of the supracrestal periodontal fibers is performed with a thin scalpel blade or a periotome on a weekly basis in order to decrease the tensile strength FIGURE 14C. Orthodontic elastic activating the FIGURE 14D. Clinical view of tooth No. 4 in the gingival tissues and bone.22 extrusion using the removable device as anchorage. first shown on Figure 14a at the conclusion of the orthodontic extrusion. Notice the increase The majority of rapid orthodontic ex- in the clinical crown length on tooth No. 4 and no trusions are performed on teeth that have Crown Lengthening in Restorative significant alteration in the position of the gingival been previously endodontically treated, Cases: Isolated Teeth margin on tooth No. 5. and no periapical problems are associated Extreme care should be exercised with such movement even in the presence when selecting periodontal surgery structure to the supragingival environ- or endodontic overfill.23 However, when as the treatment modality to achieve ment while not altering the position rapid orthodontic extrusions are performed crown lengthening of isolated teeth in of the gingival margin and the alveolar on vital teeth, rupture of the neurovascu- the esthetic zone because it will often bone. In order to achieve such an ob- lar bundle may occur and result in pulpal result in asymmetry of the gingival jective, the orthodontic movement of necrosis. Therefore, on vital teeth, slow line (FIGURE 11). In these cases, forced nonvital teeth should utilize heavy orthodontic extrusion followed by a local- tooth eruption via orthodontic extru- forces and a quick onset.20 Extrusion ized surgical procedure consisting of an api- sion presents with several advantages. rates of  mm per week are commonly cally positioned flap combined with osseous Forced tooth eruption via orthodontic achieved when orthodontic forces of resective surgery is the treatment of choice extrusion aims at exposing more tooth this magnitude are applied to teeth. to minimize the chances for pulpal necrosis.

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FIGURE 15A.Tooth No. 10 has been orthodon- FIGURE 15B. Surgical treatment of the case FIGURE 15C. Suturing of the surgical proce- tically extruded but the gingival margin has first shown on Figure 15a. Following elevation of dure shown on Figures 15a-b. inadvertently migrated in the coronal direction. A a gingival flap, minor osseous recontouring was localized resective surgical procedure is required performed. to apically position the gingival margin on tooth No. 10 as to match that on tooth No. 7. (Orthodon- tics by Dr. Eric Ting, Los Angeles.)

Orthodontic retention is an impor- tant consideration following orthodontic extrusion. Retention periods should be based on the time necessary for periodon- tal fibers to reorganize. Principal fibers of the periodontal ligament reorganize FIGURE 15D. Six-month postoperative view FIGURE 15E. Final restoration of tooth No. 10 in eight to nine weeks while supracrestal of tooth No. 10 (first shown on Figure 15a) prior to first shown on Figure 15a with a porcelain-fused periodontal fibers do so in up to 2 weeks its final preparation and impression-making. to metal crown. Notice the adequate position of following active orthodontic movement. the gingival margin in relation to teeth Nos. 9 and 11. (Restorative dentistry by Dr. Ting-Ling Chang, Therefore, a retention period lasting at Los Angeles.) least 2 weeks is indicated following orth- odontic extrusion. Fiberotomies at the end restoration to be delivered to such a tooth involves orthodontic treatment focusing of the active orthodontic extrusion have needs to compensate for that root diameter on intrusion of the upper anterior teeth if been suggested as means of preventing a discrepancy and be slightly over contoured. the desired movement of the dentogingival postorthodontic treatment coronal migra- complex in the apical direction does not tion of the gingival margin and bone.24 Crown Lengthening in Nonrestorative exceed 3 mm (FIGURES 16A-E). Orthognathic There are clinical situations in which Cases surgery combined with orthodontic coronal movement of the gingival margin The need for crown lengthening in treatment is indicated for more severe occurs following rapid orthodontic extru- the esthetic zone where no restorative cases where movement of the dentogin- sion despite all attempts to maintain the treatment is involved is usually related to gival complex in the apical direction of 4 gingival margin in its original position. In excessive gingival display, often referred mm or more is desirable. Surgical crown those cases, a localized surgical proce- to as “gummy smile.” When making lengthening via periodontal surgery to dure involving an apically positioned flap treatment decisions regarding cases reduce excessive gingival display in cases possibly combined with osseous resec- of excessive gingival display, a differ- of skeletal deformities is not the ideal tive surgery is indicated as a means to ential diagnosis is crucial in selecting treatment, as it results in root exposure and correct the discrepancy in the position the appropriate therapeutic approach. requires restoration of the teeth involved. of the gingival margin (FIGURES 15A-E). Excessive gingival display upon smil- The second situation in which A restorative challenge encountered ing may have three different causes. excessive gingival display is observed on orthodontically extruded teeth is the In the first scenario, the patient may involves cases of patients with short dimension of the diameter of the root present with a genetically determined and/or hyper mobile lips (FIGURE 17). at the gingival margin level. By virtue of skeletal deformity, where the middle third Lip dimensions and movement range its conical shape, the root diameter of an of the face presents with excessive vertical are genetically determined traits and, extruded tooth at the gingival margin level length. This skeletal characteristic is com- up until recently, little could be done is smaller than the correspondent tooth monly observed in patients who present by the dental professional to improve on the adjacent quadrant (FIGURE 12D). As a with a class II/division II malocclusion. these cases. Rosenblatt and Simon consequence, the emergence profile of the The appropriate treatment for these cases described a surgical technique involving

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coincident with the CEJ. In some indi- viduals, for unknown reasons, the passive phase of the eruption process does not FIGURE 16A. This patient’s main complaint was occur or is incomplete. This phenomenon of excessive gingival display upon smiling. Clinical ex- FIGURE 16B. Clinical view of the orthodontic is referred to as altered passive eruption amination revealed that the cause of the problem was appliance used to treat the case first shown on where the coronal margin of the alveolar dentoskeletal in nature (vertical maxillary excess) Figure 17a. and not of periodontal origin. The treatment of choice bone is located close to (less than 2 mm) was orthodontic intrusion of the upper and lower or at the level of the CEJ, which results in anterior teeth. (Courtesy of Dr. Patrick K. Turley, the gingival margin occupying a position Santa Monica, Calif.) more coronal to the CEJ than observed where the whole eruption process has occurred. The clinical crowns of teeth, in which altered passive eruption is present, tend to be square in shape and excess gingival tissue is displayed upon smiling. Cases of altered passive eruption can be successfully treated with crown lengthening via periodontal surgery (FIGURES 18A-E). It should be kept in mind FIGURE 16C. Clinical view of the case first shown FIGURE 16D. Postorthodontic treatment view that a crucial determinant of the position on Figure 16a at the conclusion of the orthodontic of the patient whose case was first shown on treatment. No periodontal surgical therapy was Figure 16a when smiling. Notice that the patient no of the gingival tissue is the underlying performed in treating this case. longer presents with excessive gingival display as bone. Therefore, in order to apically posi- evident on Figure 16a. tion the gingival margin in a sustainable fashion, osseous resection is necessary. teeth involved, besides increasing the The surgical technique selected for crown apico-coronal dimension of the clinical lengthening procedures must provide the crowns of the teeth beyond the ideal clinician with access to bone, and, as a apico-coronal/mesiodistal proportion. function of that, the periodontal flap is Crown lengthening via periodontal the technique of choice. The gingivectomy surgery is the treatment of choice in cases technique, by virtue of not allowing access where excessive gingival display is a result to the alveolar bone, is contraindicated FIGURE 17. Excessive gingival display upon of altered passive eruption. The tooth for treatment of the majority of cases that smiling because of a hyper mobile upper lip. The position of the gingival margin is adequate — eruption process can be divided into two present with altered passive eruption. slightly coronal to the cementoenamel junction — distinct periods: active and passive erup- Because cases where surgical crown and periodontal surgical therapy is not indicated. tion. Active eruption refers to the move- lengthening to treat altered passive erup- ment of the teeth in the coronal direction tion are frequently nonrestorative cases, repositioning of the upper lip, thereby up to the point at which occlusal contacts any decrease in height of interdental papil- limiting its range of motion.25 As a are established. The active phase of erup- lae as a consequence of the surgical proce- consequence of such a surgical interven- tion is followed by passive eruption where dure needs to be prevented. The clinician tion, less gingival tissue is displayed the gingival tissue and the alveolar bone treating these cases does not have the op- upon smiling. Again, crown lengthen- margin move in the apical direction. By tion of developing restorations with longer ing of the upper anterior segment via the end of adolescence, the eruption pro- interproximal surfaces so as to close the periodontal surgery is not indicated in cess is expected to be complete for most iatrogenically created spaces. Therefore, cases where excessive gingival display is teeth (with the exception of third molars) it is prudent to elevate a buccal flap only, caused by short and/or hyper mobile lips and the gingival line is located  to 3 leaving the interproximal papillae and the because it would result in root expo- mm coronal to the CEJ, with the coronal palatal tissue intact so as not to embarrass sure and the need for restoration of the end of the junctional epithelium being blood supply to those tissues and conse-

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FIGURE 18B. Treatment of the case first shown on FIGURE 18C. Suture of the flap on the case first Figure 18a. Elevation of a buccal flap confirmed the exces- shown on Figure 18a. FIGURE 18A. Clinical view of a patient sive coronal position of the alveolar bone as shown on the whose complaint was of a “gummy smile” and upper right anterior segment. Osseous resection through “square teeth.” Clinical examination revealed osteoplasty and ostectomy was performed on the upper the presence of altered passive eruption where left anterior segment. Notice the decreased buccolingual the alveolar bone crest position was coinciden- dimension of the alveolar house and the increased dis- tal with the cementoenamel junction and the tance between the bone margin and the cementoenamel gingival margin was located 3-4 mm coronal junction on the upper left teeth. to the CEJ. (Case treated by Dr. Nelson T. Yen, Fullerton, Calif. and Dr. Paulo M. Camargo.) quently decrease the probability of tissue shrinkage. If lengthening of the clinical crowns is also desirable on the palatal as- pect, the surgical procedure should be per- formed separately, leaving the buccal and interproximal tissues then undisturbed. The periodontal flap utilized for the FIGURE 18D. Sixteen-week postoperative view FIGURE 18E. Postoperative view of the patient treatment of cases where altered passive of the case first shown on Figure 18a. Notice the whose case was first shown on Figure 18a. Notice the eruption is present employs a reverse esthetically acceptable vertical/horizontal propor- absence of excessive gingival display after treatment. bevel incision. Most cases of altered tion on all teeth of the upper anterior segment. (Compare to the preoperative photograph on Figure 18a.) passive eruption occur on patients who present with a thick periodontal biotype, are often of the thick periodontal bio- finalize the osseous recontouring process. where there is an abundance of keratinized type, significant buccolingual reduction As cases of altered passive eruption may tissue. Therefore, a scalloped incision can of the buccal bone through osteoplasty is affect all teeth in the oral cavity, it is often be usually used with minimal risk of creat- required. This reduction is accomplished not possible to determine the ideal dimen- ing mucogingival problems. It should be with high-speed carbide round burs sion of the biologic width for that patient kept in mind that a minimum of 3 mm of under copious irrigation and is initiated through bone sounding under local anes- keratinized tissue (2 mm attached,  mm by the creation of apico-coronal grooves thesia as no “normal” periodontal site may nonattached) should exist following heal- in the interproximal areas; the transition be present. Therefore, the clinician needs ing of the surgical procedure. Given there between these grooves is made smooth to make an empirical decision as to the is abundance of keratinized tissue, the by further osseous reduction over the extent of the ostectomy to be performed, initial reverse bevel incision is made at the direct buccal surfaces of the roots. Once and a 2 mm distance between the CEJ and desired new level of the gingival margin, osteoplasty is completed, an ostectomy is the alveolar crest is adequate in the major- or about  mm coronal to the CEJ. A full required along the most coronal end of the ity of the cases. However, patients with a thickness flap is elevated to the mucogin- alveolar bone. An ostectomy is performed thick periodontal biotype exhibit sig- gival junction as to expose the alveolar with high-speed end-cutting burs. When nificantly more soft tissue regrowth than bone and is extended apical to the MGJ. placed parallel to the long axis of the teeth, those with a thin biotype, suggesting that Osseous resection in cases of altered end-cutting burs do not cause damage to in thick biotype patients additional bone passive eruption follows basic principles the root surfaces. An ostectomy should be removal may be beneficial in securing a of bone recontouring employed in the performed as to create a distance of 2 mm stable long-term result. In addition, it is treatment of osseous defects associated between the crest of the bone and the CEJ. important to carry the bone recontouring with periodontitis or in the execution of This space will be occupied by the bio- process to the line angles, as failure to do surgical clinical crown lengthening on logic width and the gingival margin will be so will often result in soft tissue rebound restorative cases as described previously. located slightly coronal to the CEJ. Bone and a reduced crown lengthening result. Because cases of altered passive eruption chisels and hand curettes can be used to The buccal flap is secured in place by

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interproximal interrupted sutures and the eruption. Restoration of orthodonti- 5. Källestål C, Matsson L, Criteria for assessment of inter- proximal bone loss on bite-wing radiographs in adolescents. J use of periodontal dressing is optional. cally extruded teeth may be challenging Clin Periodontol 16:300-4, 1989. Clinical healing is usually complete at six with regard to developing an emergence 6. Regan JE, Mitchell DF, Roentgenographic and dissection to eight weeks after the surgical proce- profile that matches the one of the measurements of alveolar crest height. J Am Dent Assoc 66:356-9, 1962. dure, with incremental remodel of soft tis- same tooth in the adjacent quadrant. 7. Kois J, The restorative-periodontal interface: biological sue continuing for up to six to 2 months. Periodontal surgical therapy is also parameters. Periodontology 2000, 11:29-38, 1996. the therapy of choice in treating cases 8. Gunay H, Seeger A, et al, Placement of the preparation line Conclusions and periodontal health- a prospective two-year clinical study. of excessive gingival display caused by Int J Periodontics Restorative Dent 20:171-81, 2000. Clinical crown lengthening in the altered passive eruption. It is crucial 9. Schroeder HE, Listgarten MA, Fine structure of the develop- anterior segment of the dentition for the clinician to make an appropriate ing epithelial attachment of human teeth. Monogr Dev Biol 2:1-134, 1971. requires a more elaborate and sophisti- diagnosis for cases of altered passive erup- 10. Holmes JR, Sulik WD, et al, Marginal fit of castable ceramic cated diagnostic process, and treatment tion, as the etiology of excessive gingival crown. J Prosthet Dent 67:594-9, 1992. modality selection than clinical crown display may be other than altered passive 11. Chiche GJ, Pinault A, Esthetics of anterior fixed prosthetics. Chicago, Quintessence, 1994. lengthening in the posterior segment eruption and therefore required other 12. Fradeani M, Esthetic rehabilitation in fixed prosthodontics. because the type of therapy chosen by the modalities of therapy. In executing the Volume I- Esthetic analysis: A systematic approach to pros- clinician will have esthetic ramifications surgical procedures in cases of altered thetic treatment. Chicago, Quintessence, 2004. 13. Garber DA, Salama MA, The aesthetic smile: diagnosis and that are mostly irreversible. The execu- passive eruption, it is recommended a treatment. Periodontology 2000 11:18-28, 1996. tion of the various treatment modalities palatal flap and removal of interproximal 14. Kokich VO Jr., Kiyak HA, Shapiro PA, Comparing the percep- of crown lengthening in the esthetic tissue not be performed in conjunction tion of dentists and lay people to altered dental esthetics. J Esthet Dent 11:311-24, 1999. zone also require a full understanding of with the buccal flap to minimize chances 15. Friedman N, Periodontal osseous surgery: Osteoplasty and wound healing and particular attention of creating loss of interdental papillae. ostectomy. J Periodontol 26:257-63, 1955. to detail so that a gingival scaffold that Finally, when facing the need for 16. Eissman HF, Radke RA, Postendodontic restoration. In: Cohen S, Burns RC: Pathways of the Pulp. St Louis, CV Mosby is naturally appearing can be developed. clinical crown lengthening in the esthetic Co., pp 537-75, 1976. Periodontal surgical therapy is useful zone, the clinician may be tempted to 17. Smukler H, Chaibi M, Periodontal and dental considerations in effectively achieving clinical crown select the gingivectomy technique as the in clinical crown extension: A rational basis for treatment. Int J Periodontics Rest Dent 17:465-77, 1997. lengthening for multiple contiguous therapeutic approach because of its 18. Rosenberg ES, Cho SC, Garber DA, Crown lengthening teeth in the esthetic zone. But attention apparent ease of execution. The gingivec- revisited. Compend Contin Educ Dent 20:527-32, 1999. to details in the execution of the surgical tomy technique is usually inadequate to 19. Pontoriero R, Carnevale G, Surgical crown lengthening: A 12- month clinical wound healing study. J Periodontol 72:841-8, 2001. procedure is crucial in developing a new achieve clinical crown lengthening because 20. Ingber JS, Forced eruption: Part II. A method for treating gingival line that is symmetric, scalloped, it does not provide access to the alveolar nonrestorable teeth — periodontal and restorative consider- and that allows for the execution of bone. By and large, clinical crown lengthen- ations. J Periodontol 47:203-16, 1976. 21. Kozlovsky A, Tal H, Lieberman M, Forced eruption combined prosthetic treatment that enhances the ing procedures require osseous recontour- with gingival fiberotomy. A technique for clinical crown length- maintenance of periodontal health and ing and should be combined with gingival ening. J Clin Periodontol 15:534-8, 1988. that fulfills restorative esthetic require- flaps. As previously suggested, gingivecto- 22. Pontoriero R, Celenza F Jr., et al, Rapid extrusion with fiber resection: A combined orthodontic-periodontic treatment ments. Allowing for adequate healing time mies can only be used in achieving clinical modality. Int J Periodontics Restorative Dent 7:30-43, 1987. after the surgical procedure is very im- crown lengthening in cases were horizontal 23. Simon JH, Lythgoe JB, Torabinejad M, Clinical and histo- portant in the final esthetics of the case. bone loss and/or excessive soft tissue logic evaluation of extruded endodontically treated teeth in dogs. Oral Surg Oral Med Oral Pathol 50:361-71, 1980. Forced tooth eruption via rapid depth are also present. 24. Edwards JG, A long-term prospective evaluation of the cir- orthodontic extrusion is the treatment cumferential supracrestal fiberotomy in alleviating orthodon- of choice for the isolated tooth requir- REFERENCES tic relapse. Am J Orthod Dentofacial Orthop 93:380-7, 1988. 25. Rosenblatt A, Simon Z, Lip repositioning for reduction of 1. Glossary of periodontal terms, the American Academy of ing clinical crown lengthening in the excessive gingival display: A clinical report. Int J Periodontics Periodontology. 4th ed. Chicago, 2001. esthetic zone, as it leads to the exposure Restorative Dent 26:433-7, 2006. 2. Cohen DW, Current approaches in periodontology. J Peri- of more tooth structure while maintain- odontol 35:5-18, 1964. TO REQUEST A PRINTED COPY OF THIS ARTICLE, PLEASE CON- 3. Gargiulo AW, Wentz FM, Orban B, Dimensions and relations of ing the position of the gingival line and TACT Paulo M. Camargo, DDS, MS, University of California, Los the dentogingival junction in humans. J Periodontol 32:261-7, 1961. the alveolar bone. Localized periodontal Angeles, School of Dentistry, Periodontics CHS 63048, 10833 4. Hausmann E, Allen K, Clerehugh V, What alveolar crest level Le Conte Ave., Los Angeles, CA 90095. surgical procedures may be necessary to on a bite-wing radiograph represents bone loss? J Periodontol refine esthetics following forced tooth 62:570-2, 1991.

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Etiology and Management of Whitening-induced Tooth Hypersensitivity

EDMOND R. HEWLETT, DDS

ABSTRACT Tooth hypersensitivity has long been, and continues to be, the most commonly reported adverse effect of vital tooth whitening with peroxide gels. The complex etiology of whitening-induced tooth hypersensitivity has been a major obstacle in developing a definitive strategy for its prevention. This article reviews the multiple etiologic factors implicated in whitening-induced tooth hypersensitivity and the evidence for efficacy of various strategies for its management.

 AUTHOR t-home vital tooth bleaching tooth surfaces. A definitive understand- — the dentist-dispensed/ ing of the tooth hypersensitivity issue Edmond R. Hewlett,DDS , dentist-supervised use of however, has been far more elusive, is an associate professor, a carbamide peroxide gel and, as such remains the most common restorative dentistry, University of California, in a custom-fitted tray to adverse event associated with whitening 9,2 Los Angeles, School of Awhiten teeth — was first described in of vital teeth. Reports and estimates of Dentistry. He has main- 989. Since that time, an extensive whitening-induced tooth hypersensitiv- tained a private practice in body of evidence validating the safety ity incidence range from 0 percent to 00 restorative and prosthetic and efficacy of this procedure has been percent, but are more commonly in the 60 dentistry at the UCLA 2 Faculty Group Dental established. As widespread use of percent range, and the degree of hyper- Practice. the technique became commonplace, sensitivity in these reports ranges from however, reports/descriptions of the side very mild to intolerable.5,8,3,4,6,7 Results effects of gingival irritation and tooth of a clinical trial of a 5 percent CP gel by hypersensitivity became commonplace Jorgensen and Carroll were more specific, as well.3-8 Sensitivity is the most fre- concluding that about half of all patients quently reported side effect for home tray who undergo whitening will experience whitening.9 It will commonly manifest mild sensitivity; 0 percent will have itself as generalized hypersensitivity moderate sensitivity; and 4 percent will to cold stimuli, but often also occurs as have severe sensitivity.8 Schulte et al. a spontaneous sharp shooting pain or reported that 4 percent of subjects in “zinger” limited to one or a few teeth.0 their clinical trial discontinued treatment Gingival irritation during tray tooth due to intolerable sensitivity.5 Despite the whitening is typically caused by pro- fact that the hypersensitivity is transient longed contact of the peroxide gel with (sensitivity levels typically return to gingival tissues and can be prevented by normal upon completion of, if not during, proper trimming of the tray such that the whitening treatment), it continues contact with the gel is limited to hard to render peroxide vital tooth whiten-

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ing unavailable to patients who experi- polymer thickening agent common in Amounts of peroxide measured in ence severe, intolerable hypersensitivity household products such as toothpaste, pulps of extracted teeth after simulated during the procedure.8,6,9,20 For other shampoo, and flavorings. A slightly 4-day overnight treatment with 3.5 per- patients experiencing less severe symp- acidic pH improves stability (shelf life) cent, 6 percent, and 2 percent hydrogen toms, their discomfort during whitening of these products, so small amounts of peroxide were microgram quantities, with may nonetheless adversely effect their phosphoric or citric acid are commonly no differences by peroxide concentration compliance with the procedure, and thus added as well.24 Carbamide peroxide dis- or by four-hour versus seven-hour/night produce suboptimal results. Efforts to sociates in saliva into hydrogen peroxide regimens.28 Inasmuch as milligram fully elucidate the etiology of and develop and urea (Ca[NH2]2). Urea breaks down amounts of peroxide in the pulp are nec- strategies to manage or eliminate this essary to inhibit pulpal enzymes, available side effect thus continue at robust levels. evidence strongly indicates that peroxide PENETRATION OF PEROXIDE from tooth whitening will, at worst, cause Etiology only irreversible pulpal irritation.29 Current understanding of the etiology through enamel Histological features of peroxide- of peroxide whitening-induced tooth hy- and dentin and into whitened teeth further corroborate the persensitivity is constructed around three common clinical observation that any fundamental concepts: Brännström’s the pulp during whitening-induced pulpal changes are hydrodynamic theory of tooth pain; tooth whitening has reversible.30-32 Pulpal irritation evident dentinal fluid outflow caused by osmotic histologically during treatment typically stimuli; and permeation during whiten- been reported. resolves within two weeks of terminat- ing of peroxides through enamel and ing treatment.32 Studies of long-term dentin and into the pulp. Brännström’s (six-month) treatment of tetracycline- well-known theory posits that dentinal stained teeth with at-home tray whiten- fluid expands, contracts, or flows within ing similarly do not reveal nonresolving 33 dentinal tubules under the influence of into ammonia (NH3) and carbon dioxide pulpal changes or sensitivity symptoms. thermal, evaporative, or osmotic changes (CO2). Hydrogen peroxide, considered Furthermore, sensitivity levels reported and stimulates pressure-sensitive nerve the active whitening ingredient, pen- for tetracycline-stained teeth during long- receptors (A-δ fibers) that transmit the etrates into tooth structure and breaks term whitening are not greater than those 33 stimulus and produce the perception down into oxygen (O2) and water (H2O). for teeth in normal whitening protocols. of pain.2,22 Cold is reportedly the most The released oxygen oxidizes pig- Carbamide peroxide allows for a time- common stimulus for dentin hypersensi- ment molecules in enamel and dentin release application of hydrogen peroxide tivity.22,23 While this conceptual construct to produce the whitening effect.24 and as such has been suggested as having is widely accepted, it is important to Penetration of peroxide through less potential to produce sensitivity.0 remember that tooth sensitivity during enamel and dentin and into the pulp This necessitates, however, longer tray whitening is a multifactorial phenom- during tooth whitening has been re- application times for carbamide peroxide enon and not exclusively dependent ported.25-27 Within five to 5 minutes after versus hydrogen peroxide home whitening on the use of a whitening product.2 application of whitening gel, peroxide products. Ten percent and 20 percent carb- An understanding of the chemical penetrates to the pulp where it irritates amide peroxide break down to release 3.35 entities present during vital tooth whiten- nerves and essentially produces a revers- percent and 7 percent hydrogen peroxide, ing is essential in order to consider the ible pulpitis.0,27 This etiology, then, can respectively. Carbamide peroxide releases potential of each as an etiologic agent in function independently of any osmotic 50 percent of its hydrogen peroxide in tooth hypersensitivity. Key ingredients effects on dentin (discussed later in this the first two to four hours of tray applica- in whitening gels are typically carbamide article) by whitening products, and may tion, and the remainder over next two to 34 peroxide (CH6N2O3) or hydrogen peroxide account for the common occurrence of six hours. Instructions for carbamide (H2O2), glycerin or propylene glycol as sensitivity in patients with no gingival peroxide products thus commonly recom- the carrier, carbopol — a water-soluble recession or other sites of exposed dentin. mend the options of applying the gel in

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the tray for two hours during the day cation by an OTC paint-on whitener The potential of whitening gel or overnight while asleep. While several containing ethanol but no glycerin.42 ingredients to act as osmotic stimuli on studies report no significant difference in The actual whitening process, oxidation dentin has been extensively studied. sensitivity when using 6 percent versus of organic pigments, may contribute to sen- While carbopol is a benign substance in 0 percent carbamide peroxide, these sitivity via dehydration. It has been hypoth- this regard, glycerin — also a common same studies acknowledge a trend toward esized that some of the apparent whitening ingredient in many whitening gels — is a higher incidence of sensitivity with higher effect perceived immediately upon comple- desiccant that can cause pain via dentinal concentrations of carbamide peroxide, and tion of treatment is due to saturation of the fluid outflow.8 Because of its anhydrous others demonstrate a correlation between tooth with oxygen altering the refractive in- nature and potential for tooth dehydra- sensitivity levels and carbamide peroxide tion, glycerin was implicated as the caus- concentration.20,35,36 It is also notewor- ative agent in whitening-induced tooth thy that while the higher concentration THE ACTUAL WHITENING sensitivity. Several manufacturers have products may shorten overall treatment thus replaced glycerin with water-based time by a few days, this relationship process, oxidation solutions or formulations with added is not linear (e.g., 20 percent does not of organic pigments, water, or have substituted propylene whiten twice as fast at 0 percent).0 glycol for glycerin as gel base inasmuch Dentist-dispensed whitening gels may contribute as this may also reduce sensitivity.20,47,48 containing 5 percent to 0 percent to sensitivity These strategies were initially based on hydrogen peroxide are marketed with a presumed desiccating effect of glycerin the purported advantage of shorter ap- via dehydration. on dentin, but this effect was eventu- plication time per dose versus carbamide ally directly demonstrated in vitro.42 peroxide. Hydrogen peroxide releases all Tray pressure as a cause of sensi- of its oxygen in 30 to 60 minutes of tray tivity has been suggested by findings application, hence the shorter applica- such as those by Leonard et al. who tion times in instructions for use for dex of enamel and dehydration of the tooth reported that 20 percent of participants hydrogen peroxide-containing products.37 from the oxidative process.24,43 As residual in a clinical trial experienced sensitiv- This rapid perfusion of peroxide into oxygen dissipates over the two weeks fol- ity when wearing the tray alone.20 A the pulp, however, is cited as producing lowing completion of treatment, the actual tightly adapted tray can theoretically higher sensitivity levels than an equiva- lightened shade becomes apparent.44 Re- apply active orthodontic forces effecting lent dose of carbamide peroxide.0 hydration during this period, in addition to small degrees of tooth movement and The aforementioned effects of per- restoring the normal optical properties of thus giving rise to mild levels of sen- oxides on teeth would also account for the teeth and contributing to stabilization sitivity. Trays are less rigid now versus sensitivity observed with over-the-coun- of the lightened shade, likely facilitates the early years of tray whitening and are ter whitening products, which typically re-establishment of osmotic equilibrium in less likely to exert orthodontic forces on contain 5 percent to 6 percent hydrogen the teeth and resolution of hypersensitivity. teeth.5 Additionally, a tray design using peroxide.38,39 Like dentist-dispensed Numerous studies investigating the reservoirs on the labial surfaces was pre- gels containing hydrogen peroxide, OTC efficacy of at-home whitening report sen- sumed to both reduce the tray-induced adhesive whitening strips have compa- sitivity among subjects in placebo groups sensitivity via a relaxed fit and to im- rable whitening efficacy with less contact ranging from 20 percent to 35 percent, prove efficacy by holding a larger volume time compared to 0 percent carbamide suggesting that peroxide is not the sole of whitening gel against each tooth. Re- peroxide in a custom tray.40 Greater etiologic agent.20,45,46 Placebo formula- ported evidence of these effects by reser- sensitivity has been reported with strips tions typically consist of the whitening voirs is equivocal, however, with several containing higher versus lower concentra- gel minus any peroxides. Gel composition studies finding no difference in sensi- tions of hydrogen peroxide despite the and tray fit have thus also been implicated tivity or color change when comparing shorter application time for the former.4 and investigated as possible contribu- trays with and without reservoirs.20,49 Betke et al. also reported dentin desic- tors to whitening-induced sensitivity. Crim reported that a carbamide

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peroxide whitening gel adversely affected best predictors of moderate-to-severe cellent general review of dentin hypersen- the marginal seal of class V restorations hypersensitivity during whitening.,3,5,5 sitivity, pointed out that strategies for its at the cementoenamel junction in vitro.50 Gingival recession, on the other hand, prevention are perhaps underutilized.57,59 Evidence of increased microleakage or ac- is at best a contributing factor to pre- Specifically, the role of agents that increase celerated failure of restorations subjected existing sensitivity, but not a predictor dentin surface permeability (dietary and to at-home whitening is otherwise absent — most studies have found no asso- gastric sources of acid, abrasive denti- in the literature as well as anecdotally. ciation between gingival recession and frices) must not be overlooked. Patient Available clinical data similarly do not tooth whitening.5,8 Leonard et al. ruled screening should include queries that iden- report differences in whitening-induced out patient age and gender as predic- tify potential etiologic agents in the diet hypersensitivity between restored and (acidic foods/beverages such as carbonated unrestored teeth. Teeth with carious soft drinks — especially colas — sports lesions and failing/leaking restorations GINGIVAL RECESSION, drinks, fruits and fruit juices, white are nonetheless at high risk for whiten- wine, and yogurt); digestive tract (gastric ing-induced hypersensitivity as relatively on the other hand, reflux, regurgitation); and oral hygiene large volumes of gel can directly contact is at best a contributing habits (dentifrice type, toothbrush type, deep dentin and produce sensitivity via toothbrushing technique). These factors the mechanisms described previously. It factor to pre-existing can be effectively managed by increas- is thus prudent and widely recommended sensitivity, but not ing patients’ awareness of their role in that such sites be restored at least on an tooth hypersensitivity and thus motivat- interim basis, e.g., with glass ionomer, pri- a predictor. ing patients toward modifications in diet or to initiating whitening procedures.5,52 and oral hygiene, and in seeking medical management of gastrointestinal disorders. Management Leonard et al. also recommended asking Just as the understanding of mecha- patients before whitening if their teeth are nisms at work in whitening-induced tors of sensitivity during whitening, sensitive to hot and cold, or after a prophy, hypersensitivity remains incomplete, no but a subsequent study by Matis et al. and use gentle blast of air to assess. definitive strategy for prevention of its reported higher incidence of sensitivity Acid erosion and abrasion can report- occurrence has emerged. Strategies for with females and patients under age 40 edly combine to potentiate each other’s management of hypersensitivity associ- versus males and patients over 40.,49 individual effects as etiologic agents in ated with tooth whitening such as they Prevalence of pre-existing dentinal dentin hypersensitivity.60 It has therefore currently exist include those conducted hypersensitivity has been reported to vary been recommended that patients delay prior to whitening (reduction/elimina- from 4 percent to 57 percent in the general toothbrushing until at least two hours tion of pre-existing hypersensitivity or adult population, and from 60 percent to after ingesting acidic foods or drinks to reduction of hypersensitivity risk) and 98 percent in periodontal patients.23,53-56 reduce any combined harmful effects on in conjunction with whitening (“desen- It has been suggested this broad range dentin permeability.56,57,59,60 The recom- sitizing” additives to whitening gels, and reflects the differences in the populations mendation presumes remineralization adjunctive desensitizer products for home studied and the investigation methods, of the acid-softened dentin by salivary use). Clinicians typically utilize a prod- and may also reflect structural differences calcium, phosphate, and fluoride over the uct-based approach as a first-line treat- — more and larger tubule openings — in two hours, thus restoring the dentin’s ment for hypersensitivity, but evidence sensitive versus nonsensitive dentin.57,58 It abrasion resistance. Studies attempting suggests that pretreatment assessment is nonetheless clear that a careful screen- to validate this recommendation, how- and increased focus on preventive strate- ing for hypersensitivity prior to home ever, have had varied results, including gies are equally, if not more, effective. whitening procedures is appropriate. no improvement in abrasion resistance Pre-existing hypersensitivity and a Several reports suggest that dentin hy- after one to two hours salivary remin- whitening regimen of more than one persensitivity is probably underdiagnosed eralization.6,62 Rinsing for one minute application of product per day are the and undertreated.47 Orchardson, in an ex- with a 2,000 ppm sodium fluoride solu-

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tion immediately before brushing was fect.23 Overall, however, evidence address- to in-office treatment such as sealing shown to significantly reduce abrasion ing the efficacy of potassium nitrate as a sensitive areas with adhesive resin.47 of acid-eroded dentin in vitro.63 Use of a desensitizer is equivocal. A 200 meta- The efficacy of a dentist-dispensed fluoridated mouthrinse in lieu of brush- analysis of four randomized clinical trials desensitizer gel containing 5 percent potas- ing after ingesting acidic food or drinks failed to produce conclusive evidence of sium nitrate + ,000-ppm fluoride ion for to augment the saliva’s remineralization significant efficacy for potassium nitrate use in bleaching tray has also been inves- capacity thus appears to be prudent. in reducing cervical hypersensitivity.67 tigated.2,7 Haywood et al. concluded that A common recommendation for It is also noteworthy that most 0 to 30 minutes wearing time of the gel treating whitening-induced tooth hyper- research into the desensitizing efficacy in the tray before or after whitening may sensitivity is to reduce the frequency or reduce sensitivity in more than 90 percent duration of whitening applications.8,6 of patients and make whitening tolerable.7 This approach can render the whitening PREBRUSHING WITH Leonard et al. assessed efficacy of the gel to procedure tolerable for some patients prevent or decrease sensitivity compared who would otherwise find the procedure a potassium nitrate to placebo in an at-risk population, i.e., too uncomfortable, but it does lengthen dentifrice for two weeks patients reporting pre-existing sensitivity total treatment time significantly. and risk factors.2 They reported efficacy Products used to manage dentin was reported to — 4 percent in the treatment group had hypersensitivity fall into two broad reduce sensitivity at least one day of sensitivity versus 78 per- categories: agents that reduce dentin cent in the placebo group. The gel can also permeability either by occluding tu- during whitening. be used as needed during the day or worn bule openings on exposed dentin sur- in the tray on alternating nights when an faces or by hypermineralization, and overnight whitening regimen is used.0 those that block nerve conduction. Prebrushing with a potassium nitrate Tooth pain from dentin hypersensi- dentifrice for two weeks was reported tivity is caused by depolarization, then of potassium nitrate has been examined to reduce sensitivity during whitening, repolarization resulting in activity of with respect to its use as a dentifrice and the efficacy of an OTC potassium dentinal sensory nerves. Potassium additive to desensitize cervical dentin. nitrate dentifrice worn in a tray has nitrate acts by preventing nerve repo- The degree to which it reduces sensitiv- been investigated as well.72 Tray applica- larization after initial depolarization, ity during tooth whitening when used as tion for several hours/day for one week reducing nerve excitability and the ability an additive to whitening gels remains in was shown to provide relief from tooth of the nerve to transmit pain.64,65 Like question.9,26 Tam examined the efficacy sensitivity, and 0 to 30 minutes of tray hydrogen peroxide, potassium nitrate also of 3 percent potassium nitrate and 0. application immediately prior to a dental rapidly (within minutes) filters through fluoride ion wt/vol in reducing sensitivity prophylaxis reduced discomfort during enamel and dentin and in to the pulp.63 when added to a 0 percent carbamide and after the procedure.5,73 However, Over-the-counter “desensitizing” den- peroxide whitening gel.6 The additives some toothpaste ingredients such as tifrices containing 5 percent potassium were reported to significantly reduce, but sodium lauryl sulfate (a foaming ingredi- nitrate have long been available and have not eliminate sensitivity. The study also ent) or flavorings may give rise to gingival been extensively studied. Several clinical did not attempt to differentiate between irritations (apthous ulcers) when ap- trials have reported the efficacy of potas- effects of one versus the other additive. plied in a tray for extended periods.0 sium nitrate as a dentifrice additive.67-69 Adequate evidence exists, nonetheless, Haywood nonetheless recommended Brushing with a potassium nitrate tooth- to state that potassium nitrate-contain- initially using an OTC dentifrice as paste was shown to reduce sensitivity in ing dentifrices and desensitizer gels are a tray-applied desensitizer due to its two weeks.67 Toothbrushing with potassi- indicated for management of mild of cost-effectiveness and convenience, then um nitrate dentifrice must be done twice moderate hypersensitivity.56 It is non- switching to a dentist-dispensed desen- a day as part of an ongoing brushing rou- invasive, treats multiple teeth simul- sitizer gel if gingival irritation occurs.0 tine in order to produce a desensitizing ef- taneously, and inexpensive compared Agents for desensitization via block-

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age of patent dentinal tubules include flu- scribed the following categories of these — HEMA + 4 percent chlorhexidine).26 oride, oxalate compounds, and derivatives dentist-dispensed products: potassium Several reports cite the efficacy of this of resin adhesive restorative products. Tu- oxalate (Protect, Butler; Therma-Trol, approach: An assessment of several such bule blockers have been reported to have Premier; Super Seal, Phoenix), ferric products by Clinical Research Associates, varying levels of efficacy on general dentin oxalate + acp + potassium phosphate however, found that while all reduced sensi- hypersensitivity, and their potential to (Quell, Pentron); potassium phosphate tivity, none provided relief in 00 percent of prevent whitening-induced hypersensi- + potassium carbonate + calcium chlo- cases.79-82 It should be noted that one of the tivity is limited to reduction in osmotic ride + strontium chloride (D/Sense 2, varnishes in this study, an acetone-contain- stimulation on exposed dentin surfaces. Centrix).47 Efficacy of these products for ing dentin adhesive, produced significant These agents have no effect on peroxide dehydration of the dentin samples during diffusion to the pulp and as such should its application despite creating a protective not be expected to completely eliminate THE NEWEST PRODUCTS seal against dehydration by whitener prod- whitening-induced hypersensitivity. ucts. Limitations of resin varnish desensiti- Neutral sodium fluoride works aimed at hypersensitivity zation include thin layers subject to eventual by occlusion of dentinal tubules with management are those loss via abrasion, techniques sensitivity (care fluoride precipitates; calcium fluoride must be taken to prevent moisture contami- is produced after exposure of dentin containing amorphous nation and prevent pooling of resin into to high concentrations of topical fluo- calcium phosphate as the thick layers), limited access to interproximal ride, and fluorapatite is produced after root surfaces, and expense. Additionally, exposure to lower concentrations.6 active ingredient. and as mentioned previously, these products Brushing with a fluoride gel for four have limited efficacy in reducing whitening- weeks was shown to reduce cervical induced sensitivity inasmuch as they do not hypersensitivity.74 A single application of prevent diffusion of peroxide to the pulp. a 5 percent sodium fluoride varnish has The newest products aimed at hyper- been shown to reduce cervical dentin general management of cervical hyper- sensitivity management are those con- hypersensitivity within two weeks.75 sensitivity has been demonstrated.77,78 A taining amorphous calcium phosphate as Anecdotally, the author has observed variant of this product type (Pain-Free, the active ingredient. ACP forms hydroxy- that brushing twice daily with a 5000 ppm Parkell) contains 3 percent oxalic acid + apatite in enamel and increases enamel F dentifrice for one week prewhitening 5 percent polymethyl methacrylate-co- hardness, hence its primary application as reduced discomfort during whitening. p-styrenesulfonic acid to produce a resin an agent to remineralize carious lesions, Evidence suggested that tubule blockage seal on exposed dentin along with tubule as well as reduce susceptibility to their by fluoride has limited efficacy in treat- blocking via the oxalate precipitate.47 formation. An effective delivery system ing whitening-induced hypersensitivity, Resin-based desensitizing “var- for ACP has been developed by combin- however, since the peroxide molecule is nishes” are essentially the hydrophilic ing it with casein phosphopeptide, a milk small enough to pass through the intersti- resin primer component (2-hydroxyethyl protein derivate. The resultant complex tial spaces between tubules.0 Betke et al. methacrylate, or HEMA) common to — CPP-ACP, aka Recaldent, stabilizes demonstrated that a fluoride varnish failed many adhesive resin bonding products the ACP such that it provides a reservoir to inhibit dentin dehydration by whitening with the addition of an antibacterial of calcium and phosphate that remain agents.28 It was postulated that any calci- compound. Examples include Gluma bioavailable in saliva for several hours um-fluoride precipitate formed by the var- Desensitizer (Heraeus Kulzer), origi- after application. Topical application of a nish was inadequate inhibit dehydration. nally sold as a dentin primer, an aque- CPP-ACP-containing paste (Prospec, MI Oxalate salts form a crystalline ous solution of 35 percent HEMA and Paste, GC America) has been shown to precipitate of calcium oxalate to oc- 5 percent gluteraldehyde 26; HurriSeal rapidly reduce dentin hypersensitivity, clude dentinal tubules immediately (Beutlich) — 35 percent HEMA + ben- suggesting its applicability in managing upon application, and thus reduce or zalkonium chloride+ NaF; Hemaseal whitening-induced hypersensitivity.83,84 prevent fluid movement.76 Swift de- and Cide (Advantage Dental Products) ACP (without CPP) is now present as

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an additive in some whitening prod- ing twice daily with an OTC dentifrice 15. Swift EJ, Tooth sensitivity and whitening. Compend Contin ucts as well.85 Reports of efficacy in this containing potassium nitrate for two Educ Dent 26(supp 3):4-10, 2005. 16. Tam L, Effect of potassium nitrate and fluoride on carb- regard are promising to date, with one weeks prior to whitening can reduce amide peroxide bleaching. Quintessence Int 32:766-70, 2001. clinical trial citing sensitivity remain- baseline sensitivity and risk of discom- 17. Haywood VB, Current status of nightguard vital bleaching. ing at levels similar to baseline.86 fort during whitening. The dentifrice Compend Contin Educ Dent 21(supp 28):S10-7, 2000. 18. Jorgensen MG, Carroll WB, Incidence of tooth sensitivity after can also be used in the tray for up to 30 home whitening treatment. J Am Dent Assoc 133:1076-82, 2002. Summary and Conclusions minutes before and/or after whitening 19. Auschill TM, Hellwig E, et al, Efficacy, side effects, and Whitening-induced tooth hyper- gel application to manage sensitivity patients’ acceptance of different bleaching techniques (OTC, in-office, at-home). Oper Dent 30:156-63, 2005. sensitivity is a complex, multifactorial during treatment. Dentist-dispensed 20. Leonard RH, Garland GE, et al, Safety issues when using phenomenon and as such, continues gels containing potassium nitrate for a 16 percent carbamide peroxide whitening solution. J Esthet to defy attempts to develop definitive tray application have also demonstrated Restor Dent 14:358-67, 2002. 21. Brännström M, Astrom A, The hydrodynamics of the preventive therapies. The best currently efficacy in sensitivity reduction. dentine; its possible relationship to dentinal pain. Int Dent J available evidence suggests the following: ■ Products containing amorphous 22:219-27, 1972. ■ Pretreatment assessment of calcium phosphate show promise for 22. Walters PA, Dentinal Hypersensitivity: A review. J Contemp Dent Pract 6:107-17, 2005. baseline tooth hypersensitivity is key management of sensitivity via topical 23. Addy M, Dentine hypersensitivity: new perspectives on an to the effective management of whiten- application. Whitening gels containing old problem. Int J Dent 52:367-375, 2002. ing-induced hypersensitivity. Thorough ACP may also prove to be effective in 24. Albers H, At-home bleaching. Adept Report (vol. 6) Santa Rosa: Adept Institute, 2000. screening for risk factors (acidic foods, this regard. 25. Hanks CT, Fat JC, et al, Cytotoxicity and dentin perme- gastric reflux, abrasive dentifrices) fa- ability of carbamide peroxide and hydrogen peroxide vital cilitates the elimination of these factors REFERENCES bleaching materials, in vitro. J Dent Res 72:931-8, 1993. 1. Haywood VB, Heymann HO, Nightguard vital bleaching. 26. 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39. Nathoo S, Santana E, et al, Comparative seven-day evalu- 46. Leonard RH Jr., Bentley C, et al, Nightguard vital bleaching: 68. Orchardson R, Gillam DG, The efficacy of potassium salts ation of two tooth-whitening products. Compend Contin Educ A long-term study on efficacy, shade retention. Side effects, as agents for treating dentin hypersensitivity. J Orofac Pain Dent 22:599-606, 2001. and patients’ perceptions. J Esthet Restor Dent 13:357-69, 2001. 14:9-19, 2000. 40. Gerlach RW, Gibb RD, Sagel PA, A randomized clinical trial 47. Swift EJ, Causes, prevention, and treatment of dentin 69. Schiff T, Bonta Y, et al, Desensitizing efficacy of a new comparing a novel 5.3 percent hydrogen peroxide bleaching hypersensitivity. Compen Contin Educ Dent 25:95-109, 2004. dentifrice containing 5.0 percent potassium nitrate and 04.45 strip to 10 percent, 15 percent, and 20 percent carbamide 48. Gerlach RW, Zhou X, Comparative clinical efficacy of two percent stannous fluoride. Am J Dent 3:111-5, 2000. peroxide tray-based bleaching systems. Compend Contin Educ professional bleaching systems. Compend Contin Educ Dent 70. Schiff T, Bonta Y, et al, Desensitizing efficacy of a new Dent Supplement 21:S22-8, 2000. 23(special issue):35-41, 2002. dentifrice containing 5.0 percent potassium nitrate and 04.45 41. Gerlach RW, Sagel PA, Vital bleaching with a thin peroxide 49. Matis BA, Hamdan YS, et al, A clinical evaluation of a percent stannous fluoride. Am J Dent 3:111-5, 2000. gel: The safety and efficacy of a professional strength hydrogen bleaching agent used with and without reservoirs. Oper Dent 71. Haywood VB, Caughman WF, et al, Tray delivery of potas- peroxide whitening strip. {Published erratum appears in J Am 27:5-11, 2002. sium nitrate-fluoride to reduce bleaching sensitivity. Quintes- Dent Assoc 135:156, 2004}. J Am Dent Assoc 135:98-100, 2004. 50. Crim GA, Postoperative bleaching effect on microleakage. sence Int 32:105-9, 2001. 42. Betke H, Kahler E, et al, Influence of bleaching agents and Am J Dent 5:190-12, 1992. 72. Haywood VB, Cordero R, et al, Brushing with a potassium desensitizing varnishes on the water content of dentin. Oper 51. Haywood VB, Dentine hypersensitivity: Bleaching and nitrate dentifrice to reduce bleaching sensitivity. J Clin Dent Dent 31:536-42, 2006. restorative considerations for successful management. Int 16:17-22, 2005. 43. Zantner C, Derdilopoulou F, et al, Randomized clinical trial Dent J 52(supp1):376-84, 2002. 73. Jerome CE, Acute care for unusual cases of dentinal on the efficacy of a new bleaching lacquer for self-application. 52. Nathanson D, Vital tooth bleaching: Sensitivity and pulpal hypersensitivity. Quint Int 26:715-6, 1995. Oper Dent 31:308-31, 2006. considerations. J Amer Dent Assoc 128(suppl):41S-4S, 1997. 74. Jerome CE, Acute care for unusual cases of dentinal hyper- 44. Greenwall L, Bleaching techniques in restorative dentistry. 53. Rees JS, Addy M, A cross-sectional study of dentine hyper- sensitivity. Quint Int 26:715-6, 1995. London, Martin Dunitz, 2001. sensitivity. J Clin Periodontol 29:997-1003, 2002. 75. Ritter AV, de L Dias W, et al, Treating cervical dentin hyper- 45. Matis BA, Cochran MA, et al, The efficacy and safety of a 54. Chabanski MB, Gillam DG, et al, Prevalence of cervical sensitivity with fluoride varnish. A randomized clinical study. J 10 percent carbamide peroxide bleaching gel. Quintessence Int dentine hypersensitivity in a population of patients referred Amer Dent Assoc 137: 1013-20, 2006. 29:555-63, 1998. to a specialist periodontology department. J Clin Periodontol 76. Gillam DG, Mordan AD, et al, The effects of oxalate- 23:989-92, 1996. containing products on the exposed dentin surface: An SEM 55. Taani S, Awartani F, Clinical evaluation of cervical dentin investigation. J Oral Rehab 28:1037-44, 2001. sensitivity in patients attending general dental clinics and peri- 77. Muzzin KB, Johnson R, Effects of potassium oxalate on odontal specialty clinics. J Clin Periodontol 29:118-22, 2002. dentin hypersensitivity in vivo. J Periodontol 60:151-8, 1989. 56. Taani S, Awartani F, Clinical evaluation of cervical dentin 78. Gillam DG, Coventry JF, et al, Comparison of two desensi- sensitivity in patients attending general dental clinics and peri- tizing agents for the treatment of cervical dentine hypersensi- odontal specialty clinics. J Clin Periodontol 29:118-22, 2002. tivity. Endod Dent Traumatol 13:36-9, 1997. 57. Orchardson R, Managing dentin hypersensitivity. J Am 79. Swift EJ Jr., May KN Jr., Mitchell S, Clinical evaluation of Dent Assoc 137:990-8, 2006. prime & bond 2.1 for treating cervical dentin hypersensitivity. 58. Absi EG, Addy M, Adams D, Dentine hypersensitivity. A Am J Dent 14:13-6, 2001. study of the patency of dentinal tubules in sensitive and non- 80. Dondi dall’Orologio G, Lorenzi R, et al, Dentin desensitiz- sensitive cervical dentin. J Clin Periodontol 14:280-4, 1987. ing effects of gluma alternate, health-dent desensitizer and 59. Canadian Advisory Board on Dentin Hypersensitivity. scotchbond multi-purpose. Am J Dent 12:103-6, 1999. Consensus-based recommendations on for the diagnosis and 81. Prati C, Cervellati F, et al, Treatment of cervical dentin management of dentin hypersensitivity. J Can Dent Assoc hypersensitivity with resin adhesives: Four-week evaluation. 69:221-6, 2003. Am J Dent 14:378-82, 2001. 60. Addy M, Hunter ML, Can tooth brushing damage your 82. Clinical Research Associates. Desensitizer use with restor- health? Effects on oral and dental tissues. Int J Dent 53(supp ative procedures. CRA newsletter 26(8):1-3, 2002. 3):177-86, 2003. 83. Geiger S, Matalon S, et al, The clinical effect of amorphous 61. Attin T, Buchalla W, Putz B, In vitro evaluation of different calcium phosphate on root surface hypersensitivity. Oper remineralization periods in improving the resistance of previ- Dent. 28:496-500. 2003. ously eroded bovine dentine against tooth-brushing abrasion. 84. Yates R, Owens J, et al, A split-mouth placebo-controlled Arch Oral Biol 46:871-4, 2001. study to determine the effects of amorphous calcium 62. Hara AT, Turssi CP, et al, Abrasive wear on eroded root phosphate in the treatment of dentine hypersensitivity. J Clin dentine after different periods of exposure to saliva in situ. Periodontol 25:687-92, 1998. Eur J Oral Sci 111:423-7, 2003. 85. Giniger M, Macdonald J, et al, The clinical performance of a 63. Attin T, Zirkel C, Hellwig E, Brushing abrasion of eroded professionally dispensed bleaching gel with added amorphous dentin after application of sodium fluoride solutions. Caries calcium phosphate. J Am Dent Assoc 136:383-92, 2005. Res 32:344-50. 86. Giniger M, Spaid M, et al, A 180-day clinical investigation 64. Markowitz K, Kim S, Hypersensitive teeth. Experimental of the tooth whitening efficacy of a bleaching gel with added studies of dentinal desensitizing agents. Dent Clin North Am amorphous calcium phosphate. J Clin Dent 16:11-6, 2005. 34:491-501, 1990. 65. Touyz LZG, Stern J, Hypersensitive dentinal pain attenua- TO REQUEST A PRINTED COPY OF THIS ARTICLE, PLEASE CONTACT tion with potassium nitrate. Gen Dent 47:42-5, 1999. Edmond R. Hewlett, DDS, University of California, Los Angeles, 66. Hodosh M, A superior desensitizer — potassium nitrate. J School of Dentistry, 10833 Le Conte Ave., Box 951668, Los Am Dent Assoc 88:831-2, 1974. Angeles, CA 90095. 67. Silverman G, Berman E, et al, Assessing the efficacy of three dentifrices in the treatment of dentinal hypersensitivity. J Am Dent Assoc 127:191-201, 1996.

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Perspectives on the 2007 AHA Endocarditis Prevention Guidelines THOMAS J. PALLASCH, DDS, MS

ABSTRACT From 2005 to 2007, the American Heart Association convened a consensus panel of experts to revisit the guidelines for the premedication of patients with cardiac defects prior to dental treatment. Presented in this article is a summary of the guidelines as well as commentary on the process.

AUTHOR DISCLOSURE his year is the 98th anniver- bacteria originating in the oral cavity or 3,4 Thomas J. Pallasch, DDS, The author was a member sary of the contention that the tonsils. Curiously, virtually all foci MS, is emeritus professor of the Writing Group for “previously sclerosed endocar- of infection were surgically accessible. of dentistry, University the 2007 Prevention of ditis” was, in most cases, due Th is era is presently being revisited, but of Southern California Infective Endocarditis to mouth microorganisms. It more about that later. Th e Focal Infec- School of Dentistry, Los Guidelines from the also is approximately 80 years since den- tion Th eory clearly brought to light the Angeles. American Heart Associa- T tion. The opinions stated tal treatment procedures were considered apparent necessity of medicine to fi nd a herein are not necessarily a primary cause of infective endocarditis, reason for everything, including blaming those of the American even as data increasingly accumulated dentistry and the oral fl ora for endocardi- Heart Association Per- that random bacteremias associated tis and just about everything else. Some spectives on the 2007 AHA with daily living activities (brushing, fi nd it very diffi cult to say, “I don’t know.” Endocarditis Prevention Guidelines. fl ossing, mastication) were similar in Beginning around the early 980s, a magnitude and incidence to those as- few bold individuals began to contest this sociated with dental treatment. Most conventional wisdom and suggest that failed to realize that dental treatment dental treatment was not responsible occurred only a few times a year, while for many, or even any, of these infective the bacteremias associated with daily endocarditis (IE) cases.5-27 Some became living were more or less continuous.2 weary of being accused of seriously Th ese early conclusions were severely injuring or even killing dental patients biased as they occurred during the heyday by physicians who blithely ignored their of the Focal Th eory of Infection, which own record of hundreds of thousands of attributed essentially every disease that nosocomial (hospital-acquired) deaths was untreatable or of unknown etiology per year due to mistakes and multiple (most of them), including arthritis to antibiotic resistant microorganisms. gastrointestinal upset and stupidity to Little attention was paid to the incuba-

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TABLE 1

27 Recommendations of the 2007 AHA Endocarditis Prevention Guidelines

Dental Procedures for Which Endocarditis Prophylaxis is Recommended All dental procedures that involve manipulation of gingival tissue or the periapical region of the teeth or perforation of the oral mucosa Cardiac Conditions Associated With the Highest Risk of Adverse Outcomes From Endocarditis for Which Prophylaxis With Dental Procedures Is Recommended: ■ Prosthetic heart valve ■ Previous endocarditis ■ Cardiac transplant recipients who develop cardiac valvulopathy ■ Congenital heart disease (only for conditions listed below and no other CHD) ■ Unrepaired cyanotic congenital heart disease (CHD), including palliative stents and conduits ■ Completely repaired congenital heart defect with prosthetic material or device, whether placed by surgery or by catheter intervention, during the first six months after the procedure ■ Repaired CHD with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device (which inhibit endothelialization) Oral Prophylaxis Regimens Prior to a Dental Procedure in the Above Situations Single dose 30 minutes to 60 minutes before procedure

Situation Agent Adults Children Oral amoxicillin 2 grams 50 mg/kg

clindamycin 600 mg 20 mg/kg or Allergic to penicillins cephalexin1 2 grams 50 mg/kg or azithromycin or clarithromycin 500 mg 15 mg/kg

* Cephalosporins should not be used in an individual with a history of anaphylaxis, angioedema, or urticaria with penicillins. tion period (the time from the onset of the was inevitably followed by: “That did The major changes in the preven- bacteremia to the first signs and symptoms) it!” Two hundred and seventy days tion of endocarditis in the 2007 AHA of viridans group streptococcal (VGS) en- between dental treatment and the onset guidelines are: ) only an extremely small docarditis (usually seven to 4 days), or that of symptoms may be the world record. number of cases of IE might be prevented the alleged causative bacteremia could more Recently, a cardiologist stated he could by antibiotic prophylaxis for dental easily have come from daily living activities think of nothing else in the six months procedures, even if such prophylaxis were before or after the dental treatment. It was after the dental treatment that could 00 percent effective; 2) IE prophylaxis for impossible to tell which it was, but that was have caused the VGS endocarditis. dental procedures should be recommend- considered irrelevant. The author has been With the advent of the 2007 American ed only for patients with underlying car- involved for more than 35 years in malprac- Heart Association Prevention of Infective diac conditions associated with the high- tice litigation involving endocarditis causa- Endocarditis guidelines, it is hoped that est risk of adverse outcome from IE; 3) for tion (more than 300 cases) with only three much or all of this thinking will change.27 patients with these underlying conditions, occurring within this incubation period ( However one must recall the observa- prophylaxis is recommended for all dental percent). It was similarly impossible in these tion of a noted scientist that a new idea procedures that involve manipulation of few situations to determine causality from is accepted only when all its critics are the gingival tissue or the periapical region dental treatment or daily living bacteremias. dead. Unfortunately, the proponents of of the teeth or perforation of the oral In all these cases, without exception, the idea will also likely have passed on. mucosa; and 4) prophylaxis is not recom- the question was asked in the hospital In the words of Schopenhauer, “All truth mended based solely on an increased life- usually of a relative: When was their last passes through three stages. First it is time risk of acquisition of infective endo- dental treatment? A positive response ridiculed. Second it is violently opposed. carditis.27 TABLE 1 places these indications of “yesterday” up to “nine months ago” Third it is accepted as being self-evident.” and antibiotic doses in a single chart.

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Th e most fundamental conceptual Th e cumulative daily exposure for one sis (/4,000); rheumatic heart disease change since the 997 guidelines is that year of daily living activities may pose (/42,000); congenital heart disease the 2007 recommendations are based a 5.6 million times greater bacteremic (/475,000); and mitral valve prolapse not solely on the lifetime risk of acquisi- risk than a single tooth extraction.22 (/. million).2,32 Th erefore, the number tion of IE but rather on the highest risk Possibly the most devastating argu- of cases of IE arising from dental treat- of adverse outcomes from IE. It is not ment against antibiotic prophylaxis for ment is exceedingly small as would be any the risk of contracting IE, but rather the prevention of dental treatment-induced benefi t from antibiotic prophylaxis.27 It is seriousness of outcome of the disease. endocarditis is the absolute risk rate quite possible the risk of death from peni- Th e AHA 2007 guidelines also list the estimation of IE causation. If 250 mil- cillin-induced anaphylaxis is greater than primary reasons for this revision of IE any proposed benefi t in this scenario.,4 prophylaxis guidelines: ) IE is much more Th ere is no data that bleeding during likely to result from frequent exposure to dental procedures is a realistic predic- random bacteremias associated with daily ONLY AN EXTREMELY tor of bacteremia.27 It has always been activities than from bacteremia caused by assumed that if antibiotic prophylaxis a dental, GI tract, or GU tract procedure; small number reduces the incidence or magnitude of 2) prophylaxis may prevent an exceed- of cases of IE might bacteremias, then this is a good surrogate ingly small number of cases of IE, if any, marker for prevention of IE. Th ere is no in individuals who undergo a dental, GI be prevented evidence that this assumption is true.27 tract, or GU tract procedure; 3) the risk of by antibiotic Th e absence of evidence is also antibiotic-associated adverse events ex- evidence. Th ere are no consistent data ceeds the benefi t, if any, from prophylac- prophylaxis for to support the idea that the greater tic antibiotic therapy; and 4) maintenance dental procedures. the magnitude of the bacteremia, the of optimal oral health and hygiene may greater the risk of IE.27 Th e infective reduce the incidence of bacteremia from dose (inoculum size) of bacteria needed daily living activities and is more impor- to cause endocarditis is unknown as tant than prophylactic antibiotics for a lion people visit the dentist on average is the duration of the bacteremia.27 dental procedure to reduce the risk of IE.27 of .6 times per year (400 million visits Whether a “clean” mouth is more per year) and the incidence of infective preventive of IE than a “dirty” mouth is Supporting Evidence endocarditis is ,200 cases annually in contentious since there is only equivo- Th e evidence supporting these conclu- the United States with a population of cal data to support this assertion.27 sions is formidable. Two observational 280 million with a risk rate of 4.0/00,000 Less than 20 cases of endocarditis due studies found no association between population and 25 percent caused by to periodontopathic microorganisms dental treatment and endocarditis.28,29 VGS, then the absolute risk rate is have been reported in the literature None have ever shown any association. /42,000 persons for VGS endocarditis with most of these due to Actinobacillus Th ese and other studies have concluded if all are caused by dental treatment.2 actinomycetemcommitans.2 Viridans group that only a very low number of IE cases If it is further assumed that  percent streptococci dominate in a clean, healthy could ever be prevented with antibiotic of all VGS cases annually in the United mouth.27 Th ere are no clinical studies to prophylaxis prior to dental treatment States (2 cases) are caused by dental document that a reduction bacteremias even if such prophylaxis were 00 percent treatment, then the absolute risk rate allegedly seen with a healthy mouth eff ective.30,3 Th e risks of bacteremia as- rises to /4,000,000 in the general popu- reduces the incidence of IE. Practitioners sociated with daily living far surpasses lation with no known cardiac risk factors.2 must be careful of surrogate markers and any associated with dental treatment: Th e worst-case absolute risk for endocar- theory falsely rising to the level of fact. the risk of tooth brushing twice a day ditis from a single dental treatment pro- for one year has more than 50,000 cedure rises substantially in persons with The Role of Microbial Resistance times greater risk for exposure to bac- known cardiac risk factors: previous endo- Th e world is in the grip of an epidemic teremia that a single tooth extraction.22 carditis (/95,000); cardiac valve prosthe- of multiple antibiotic resistant microbial

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pathogens resulting in more than 8 mil- IE and places at serious risk any attempt by odontal pathogens are uniquely involved lion deaths annually, not counting AIDS.33 a national registry to document the eff ect in the infection/infl ammation observed in It is often heard regarding antibiotic of these new guidelines on endocarditis in- convoluted, sticky atherosclerotic plaque prophylaxis that “It’s only a single dose!” cidence. If a strict case defi nition of endo- endlessly buff eted by bacteremias is fanci- However, this therapeutic strategy denies carditis is not employed (unlikely without ful in the light of the detection of over the fact that antibiotics are “societal access to patient records to verify the diag- 50 diff erent microbial species in coronary drugs” that aff ect those nearby (family nosis by the Duke Criteria) then the results artery plaque.38 If the data in the AHA members) and others globally by foster- of such a registry will be very misleading. guidelines tell us anything, it is that bacte- ing the creation of resistant microbes and Litigation is likely to continue with rial assault on the human is unremitting the transfer their genes.33,34 Th e prescriber lawyers attempting to “test the waters” and our welfare utterly dependent on our of antibiotic prophylaxis (or therapy) as- innate and acquired immune systems sumes this is the only time the antibiotic along with other factors subsequently is being used (health care professionals discussed, which, from time to time, fail. tend to think very locally rather than glob- EQUALLY REMARKABLE Since the incidence and prevalence ally) when it is actually being employed in is the ability of the of IE has not changed with the advent a similar fashion millions of times per day. of antibiotic therapy, in spite of all our lungs, spleen, liver, and eff orts to reverse this state of aff airs, it The Lawyers reticuloendothelial is likely that other factors are primarily One of the major factors in the over- involved.3 Persons with predisposing use of antibiotics is that they are “drugs system to clear the factors for endocarditis acquisition are of fear” commonly employed to prevent blood of bacteria. subjected to an endless assault of bacte- negligence allegations and to assert remias, yet only a few ever develop IE. that “all was done” to treat the patient.35 Certainly the ability of the microorganism Th is is true with antibiotic prophylaxis to adhere to the valvular vegetation is probably more than any other applica- with “experts” who disagree with the very important as is the possibility of the tion of the drugs. Th is gross overuse of preponderance of evidence in the 2007 organism gaining virulence genes for IE antibiotics has led to the declining effi cacy AHA guidelines. One means of combat- from bacteriophages, plasmids, and trans- of the penicillins particularly against ing these allegations of negligence is to posons.27,33 Th e ability of microorganisms oral microorganisms due to microbial carefully record in the dental records that to transfer genetic information among resistance, making it even less likely “in my best clinical judgment” this was themselves is nothing short of remark- that prophylaxis will be successful.2,27,33 the proper treatment of the patient. Th is able and staphylococci and streptococci need not be restricted to the question of are very adept at sticking to surfaces.33 Other Observations endocarditis prophylaxis but any dental Equally remarkable is the ability of the A recent feature of endocarditis litiga- procedure that could be judged improper lungs, spleen, liver, and reticuloendothe- tion is the appearance of lawsuits against with the faultless wisdom of hindsight. lial system to clear the blood of bacteria. dentists who followed the 997 AHA Dentistry is in danger of creating a One of the more intriguing aspects of guidelines to perfection; also the inability similar situation but in reverse. Some are endocarditis is that it may be a platelet of medicine to commonly employ the Duke attempting to employ the long-discredited disease rather than primarily an infec- Criteria in the diagnosis of IE.36,37 Often Focal Infection Th eory to “prove” the oral tious one. Platelets are at the very center the disease is “diagnosed” on the basis of a cavity, particularly periodontal disease of IE as they, along with fi brin, form the patient-reported fever, one or two positive has “systemic ramifi cations.” Th e current vegetation that extends from the cardiac blood cultures (commonly taken a few min- research is limited at best, and, at worst, valve surface and becomes infected by utes apart) and a cardiac murmur with or faulty in its conclusions. It is unlikely that bacteria. Secondly, the platelets have very without a confi rmatory echocardiogram for weak odds ratios and wide confi dence signifi cant antibacterial activity both in a fl ail vegetation. Th is likely leads to a sub- intervals are going to convince a skeptical the blood and at the interface with micro- stantial overestimation of the incidence of scientifi c community. Claiming that peri- organisms at the surface of the vegeta-

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TABLE 2 Medical conditions for which no antibiotic prophylaxis is recommended before dental treatment.40-42 tion. Thirdly, once the vegetation becomes the risk-benefit ratio is even less than IE.2 ■ Arterial grafts fully established, the antibacterial platelet The subject of other cardiovascular activity and host defenses may be insuf- infections due to transient bacteremias ■ Asplenia ficient to overcome the rapidly multiply- has been addressed by another AHA ■ ing bacteria.39 Thus, the loss of platelet publication with no prophylaxis prior Breast and penile implants antimicrobial activity, a deficient innate to dental treatment for pacemakers and ■ Cardiac pacemakers and implanted and acquired immune response, failure implantable cardioverter-defibrillators, defibrillators to clear the blood of microorganisms, peripheral vascular stents, prosthetic bacterial adhesion factors, and microbial vascular grafts, coronary artery stents, ■ Cerebrospinal fluid shunts 40 virulence may be at the heart of IE (no and left ventricular assist devices. There ■ Dacron carotid patches pun intended) rather than the bactere- is no data to support prophylaxis in these mia per se, since it occurs endlessly and situations and the risk from bactermias is ■ Diabetes mellitus rarely produces a problem. As with most very low, if at all. A recent comprehensive ■ HIV/AIDS calamities, it takes a confluence of del- study by Lockhart et al. has methodically eterious events to create the misfortune explored the scientific evidence for antibi- ■ Immunosuppression secondary to cancer/ rather than a single untoward mishap. otic prophylaxis prior to dental treatment cancer chemotherapy Another interesting aspect of anti- in patients with cardiac-native heart valve ■ biotic prophylaxis is the scant attention disease; prosthetic heart valves and pace- Left ventricular assist devices paid to the millions who receive the makers; hip, knee, and shoulder prosthet- ■ Orthopedic pins and screws antibiotics but will never benefit from ic joints; renal dialysis shunts; vascular them since the disease to be “prevented” grafts; immunosuppression secondary to ■ Orthopedic prosthetic joints is so rare. Antibiotic prophylaxis in a cancer and cancer chemotherapy; sys- ■ Peripheral and coronary artery stents large population is a poor public health temic lupus erythematosus; and insulin- measure since, unlike fluoridation and dependent (Type I) diabetes mellitus.4 ■ Renal dialysis shunts immunization, where almost all benefit The authors found little or no evi- ■ and the risk-benefit ratio is very favorable, dence to support antibiotic prophylaxis in Solid organ transplants without cardiac valvulopathy antibiotic prophylaxis is rarely, if ever, these patients or that it prevents distant successful except in hospital situations for site infections for any of these eight ■ Systemic lupus erythematosus surgical infection prevention, and then groups of patients.4 Other situations for only under a strict protocol. The prin- which there is no documented benefit of ciples of antibiotic prophylaxis are well antibiotic prophylaxis include breast and that 7), temporal associations are the established but rather poorly followed.2 penile implants and asplenia42 (TABLE 2). weakest of all epidemiologic correlations.26 Certainly the tendency of the health Other Antibiotic Prophylaxis Situations How Did This All Happen? sciences to concentrate only on the situ- Questions naturally arise as to wheth- The propensity for blaming dental ation at hand (a patient) to the exclusion er the AHA guidelines apply to other med- treatment procedures for IE arose from of any other more global considerations ical conditions that have been proposed several observations and events: ) the is very common. That antibiotic prophy- for antibiotic prophylaxis. The answer advent and then demise of the Focal laxis and antibiotics in general are drugs is generally “no.” However, the lessons Theory of Infection; 2) the discovery that that affect the entire world population learned can be applied to prophylaxis for dental procedures induce bacteremias is of little importance. All that counts dental patients with prosthetic orthopedic particularly with VGS; 3) that VGS are a is this patient in front of me. All must joints with even less risk of infection, if common cause of IE; 4) the failure to be done to save this one patient to the any at all, from dental treatment-induced appreciate random spontaneous bactere- exclusion of any deleterious effects bacteremias. There still is no documented mias; 5) inattention to the incubation on others in the population. Even the case of a prosthetic joint infection from a period of IE; 6) the necessity to find a best of intentions are no substitute dental treatment-induced bacteremia and culprit for the IE, hopefully, a dentist; and for logic and the scientific method.

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Dentistry in its passivity basically sat All who receive a statin will likely cheat What to Do With the Patient and on its hands for more than 50 years and death from coronary artery disease. Th e Physician allowed medicine to avoid the necessity reality is that probably for only a limited Th e most obvious questions about the to say “I don’t know” by blaming us for number of persons is this true.43,44 new AHA endocarditis guidelines is what endocarditis. One wonders what they A NNT analysis will determine the to say to the patient who has taken antibi- say when there is no one to blame it on. actual number of persons in a given otic prophylaxis previously before dental A corollary is that putting the blame on population who will benefi t from the treatment, or their physician who refuses dentists avoids involvement in litigation. drug or procedure, and the NNH the to abide by these guidelines. Th e guide- number harmed by the therapy.43,44 lines list several talking points as listed Lessons Learned previously regarding the much greater risk Be wary of the tendency as described from random daily bacteremias, the lim- by Einstein for “the theory to determine ited effi cacy of antibiotic prophylaxis, its what we observe.” Often, scientists BE WARY OF potential harm, and the potential benefi ts fi nd what they want to fi nd, not what of good oral health. Th is will certainly help they should fi nd. Th ere is an incredible the tendency as to explain the changes and may be all that amount of “reverse investigation” going described by Einstein is necessary. However, these do not ad- on where the fi nal result is predeter- dress the recalcitrant patient or physician. mined and only data that supports this for “the theory Toward this end, the following state- conclusion is accepted. Be suspicious to determine what ment may be appropriate, “Th ese new when the theory has not passed the test 2007 American Heart Association (AHA) of biologic plausibility (biologic sense). we observe.” guidelines for the prevention of infective Does it make sense to give antibi- endocarditis may be confusing to patients otic prophylaxis to 00,000 to a million who have taken antibiotic prophylaxis in individuals to try to save one from IE? the past prior to dental treatment and are What does one do about the 99,999 to now advised that it is unnecessary. Th ese 999,999 who will not benefi t and will How many patients will it take to new recommendations are based upon the possibly suff er harm? Does it make sense prevent one acute myocardial infarc- best current scientifi c evidence regarding to blame the dentist when it is impossible tion by “dental treatment”? Is it /0, risk, benefi t and effi cacy of antibiotic pro- to determine which bacteremia caused /00, /000, /0,000 (assuming it phylaxis to prevent infective (bacterial) en- the IE? Does it make sense to say oral has any benefi t at all), or in the case docarditis. If the physician and/or patient bacteria causes cardiovascular disease of endocarditis prevention approach- chooses not to follow these recommenda- when this disorder is one of the compli- ing infi nity? What will the cost be to tions, they do so on their own authority. cated known to science with up to 200 “save” this one person: $000, $0,000, If the advice of the dentist and AHA are real or potential markers or risk factors? $ million?45 We simply don’t know. Yet in confl ict with that of the physician, then An important statistical device that is our patients have a right to know this. the physician can prescribe the antibiotic rarely employed today in clinical stud- Th e cost to “save” one person from prophylaxis on their own authority.” ies since it would seriously undermine an endocarditis death using the 990 With any dental treatment or decision most health-associated therapies is the AHA guidelines was estimated to be $3 that may be subjected to the infallible concept of the “numbers needed to treat million per life saved and $300,000 for hindsight judgment of a plaintiff attor- (NNT)” or conversely the “numbers each case prevented (VGS-associated ney or a critical “expert,” it would again needed to harm (NNH).” Th is is particu- IE is about 0 percent or less fatal).42 be wise to place in the dental records the larly true for chronic diseases that require A numbers needed to treat analysis of statement that this was determined “by long-term longitudinal studies that, all proposed clinical therapies should my best clinical judgment.” Th is demon- unfortunately, are rarely done. It is often be mandatory in this day and age of strates particular attention to a poten- assumed that every person who receives unbridled “scientifi c” hype, particularly tially controversial judgment decision. It periodontal therapy benefi ts from it. when “published by press release.” will be tempting to just go along with the

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ill-advised advice of the physician, but two 5. Podgrell MA, Welsby PD, The dentist and prevention of 28. Strom BL, Abrutyn E, et al, Dental and cardiac risk factors infective endocarditis. Br Dent J 139:12-6, 1975. for infective endocarditis: A population-based, case-control wrongs do not make a right . A primer by 6. Everett ED, Hirschman JV, Transient bacteremia and study. Ann Int Med 129:761-9, 1998. Brown et al. addresses the proper format endocarditis prophylaxis: A review. Medicine (Baltimore) 29. Lacassin F, Hoen B, et al, Procedures associated with infec- for the dentist-physician consultation.46 56:61-7, 1977. tive endocarditis in adults: A case control study. Europ Heart J 7. Oakley C, Somerville W, Prevention of infective endocardi- 16:1968-74, 1995. tis. Br Heart J 45(3):233-5, 1981. 30. van der Meer JT, Van Wijk W, et al, Efficacy of antibiotic Clinical Caveats 8. Guntheroth WG, How important are dental procedures as prophylaxis for prevention of native-valve endocarditis. If the antibiotic dosage is inadvertently a cause of infective endocarditis? Amer J Cardiol 54:797-801, Lancet 339:135-9, 1992. 1984. 31. Duval X, Alla F, et al, Estimated risk of endocarditis in not administered before the procedure, the 9. Kaye D, Prophylaxis for endocarditis: An update. Ann Int adults with predisposing cardiac conditions undergoing dental drug may be administered up to two hours Med 104:419-23, 1986. procedures with or without antibiotic prophylaxis. Clin Infect after the procedure.27 There is no data to 10. Pallasch TJ, A critique of antibiotic prophylaxis. J Calif Dent Dis 42:e102-7, 2006. Assoc 14:28-36, 1986. 32. Steckelberg JM, Wilson WR. Risk factors for infective support the concept that preprocedural 11. Tzukert AA, Leviner E, Banoliel R, et al, Analysis of the endocarditis. Infect Dis Clin North Am 7:9-19, 1993. oral antibacterial rinses prevent IE and are American Heart Association’s recommendations for preven- 33. Pallasch TJ, Antibiotic resistance. Dent Clin North Am not recommended.27 Routine dental proce- tion of infective endocarditis. Oral Surg Oral Med Oral Path 47:665-79, 2003. 62:276-9, 1986. 34. Levy SB, The antibiotic paradox. 2nd ed., Plenum Publish- dures should be scheduled, if possible, at 12. Oakley CM, Controversies in the prophylaxis of infective ing, Cambridge, Mass., 2002 least 0 days apart if the same prophylactic endocarditis. J Antimicrob Chemother 20(Suppl A):99-104, 35. Kunin CM, Editorial response: Antibiotic armageddon. Clin antibiotic is employed. Alternately, for 1987. Infect Dis 25:240-1, 1997. 13. Young SEJ, Aetiology and epidemiology of infective endo- 36. Durack DT, Lukes AS, Bright DK, Duke Endocarditis shorter intervals another approved antibi- carditis. J Antimicrob Chemother 20 (Suppl A):7-14, 1987. Service. New criteria for diagnosis of infective endocarditis: otic (e.g., clindamycin) can be employed.27 14. Pallasch TJ, A critical appraisal of antibiotic prophylaxis. Int Utilization of specific endocardiographic findings. Amer J Med Dent J 39:183-96, 1989. 96:200-29, 1994. 15. McGowan DA, Dentists and endocarditis. Br Dent J 169:69, 37. Li JS, Sexton DJ, et al, Proposed modification to the Duke Conclusions 1990. criteria for the diagnosis of infective endocarditis. Clin Infect The 2007 AHA endocarditis prevention 16. Pallasch TJ, Slots J, Antibiotic prophylaxis for medical-risk Dis 30:633-8, 2000. guidelines are a meticulous and expert patients. J Periodontol 62:227-31, 1991. 38. Ott SJ, El Mokhtari NE, et al, Detection of diverse bacterial 17. Simmons NA, Ball AP, et al, Antibiotic prophylaxis and infec- signatures in atherosclerotic lesions of patients with coronary presentation of the scientific data regard- tive endocarditis. Lancet 339:1292-3, 1992. heart disease. Circulation 113:929-37, 2006. ing the prevention of endocarditis by 18. Wahl MJ, Myths of dental-induced endocarditis. Ann Int 39. Fitzgerald JR, Foster TJ, Cox D, The interaction of bacterial antibiotic prophylaxis. It also establishes, Med 154:137-44, 1994. pathogens with platelets. Nature Rev Microbiol 4:445-57, 19. Pallasch TJ, Slots J, Antibiotic prophylaxis and the medi- 2006. finally, that dental treatment is very rarely, cally compromised patient. Periodontol 2000 10:107-38, 1996. 40. Baddour LM, Bettmann MA, et al, Nonvalvular cardiovascu- if at all, a cause of IE, and that antibiotic 20. Pallasch TJ, Antibiotic prophylaxis: The clinical significance lar device-related infections. Circulation 108:2015-31, 2003. prophylaxis is not established as preven- of its recent evolution. J Calif Dent Assoc 25:619-32, 1997. 41. Lockhart PB, Loven B, et al, The evidence base for the ef- 21. Durack DT, Antibiotics for prevention of endocarditis ficacy of antibiotic prophylaxis in dental practice. J Amer Dent tive and should only be employed in the during dental treatment: Time to scale back. Ann Int Med Assoc 138:458-74, 2007. very highest risk patients for the sequellae 129:829-31, 1998. 42. Pallasch TJ, Antibiotic prophylaxis. In: Pharmacology and to IE. The guidelines are strictly evidence- 22. Roberts GJ, Dentists are innocent! “Everyday” bacteremia therapeutics for dentistry (Yagiela JA, Dowd FL, Neidle EA, is the real culprit: A review and assessment of the evidence eds.) 5th ed., Elsevier Mosby, St. Louis, 2004. based. Assurances are given that sound that dental surgical procedures are a principal cause of bacte- 43. Ebrahim S, The use of numbers needed to treat derived new data will be reviewed and incorporated rial endocarditis in children. Pediat Cardiol 20:317-25, 1999. from systematic reviews and meta-analysis: Caveats and in future guidelines when appropriate 23. Lockhart PB, Durack DT, Oral microflora as a cause of pitfalls. Eval Health Professions 24:152-64, 2001. endocarditis and other distant site infections. Infect Dis Clin 44. Barratt A, Wyer PC, et al, Tips for learners of evidence- as science is a long evolutionary process North Am 13(4):833-50, 1999. based medicine: 1. Relative risk reduction, absolute risk of discovery. The American Heart As- 24. Lockhart PB, The risk of endocarditis in dental practice. reduction and number needed to treat. Canad Med Assoc J sociation has done well in following the Periodontol 2000 23:127-35, 2000. 171:353-8, 2004. 25. Pallasch TJ, Antibiotic prophylaxis. Endodontic Topics 45. Hamilton J, The link between periodontal disease and data. Its critics should do the same. 4:46-59, 2003. systemic diseases: State of the evidence. J Calif Dent Assoc 26. Wahl MJ, Pallasch TJ, Dentistry and endocarditis. Curr 33:29-38, 2005. REFERENCES Infect Dis Reports 7:251-6, 2005. 46. Brown RS, Farquharson AA, Pallasch TJ, Medical consulta- 1. Ashrafian H, Bogle RG, Antimicrobial prophylaxis for endo- 27. Wilson W, Taubert KA, et al, Prevention of infective endo- tions for medically complex dental patients. J Calif Dent Assoc carditis: Emotion or science? Heart 93:5-6, 2007. carditis. Guidelines from the American Heart Association. A 35:343-9, 2007. 2. Pallasch TJ, Antibiotic prophylaxis: Problems in paradise. guideline from the American Heart Association rheumatic fe- Dent Clin North Am 47:665-79, 2003. ver, endocarditis and Kawasaki disease committee, council on TO REQUEST A PRINTED COPY OF THIS ARTICLE, PLEASE 3. Pallasch TJ, Wahl M, The focal infection theory: Appraisal cardiovascular disease in the young, and the council on clinical CONTACT Thomas J. Pallasch, DDS, MS, 343 Helmuth Lane, and reappraisal. J Calif Dent Assoc 28:194-200, 2000. cardiology, council on cardiovascular surgery and anesthesia, Alexandria, VA 22304. 4. Pallasch TJ, Wahl M, Focal infection: New age or ancient and the quality of care outcomes research interdisciplinary history? Endodontic Topics 4:32-45, 2003. working group. Circulation 2007 Single reprint, (800) 242-8721.

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No Apologies!

That phrase is viewed as Auto insurance companies have very medicine has established that time spent explicit instructions for their clients who cooling one’s heels in the reception room an admission of guilt in may be involved in an accident. More or in subsequent examination cells does important than the exchange of licenses not require an “I’m sorry” response. This legalese just the same as and insurance information is the admoni- proved so popular, the concept came to in- it is in your marriage. tion to never volunteer the words, “I’m clude nose jobs, tummy tucks, and pillow sorry.” Even if you were obviously at lips, as well as a host of other procedures fault driving under the influence on the with potentially untoward results. wrong side of the freeway with a 2-pack ProMutual Group, a Boston company , of empty beer bottles floating around the that insures 8,000 physicians, dentists, Robert E. driver’s compartment, “I’m sorry” is an and healthcare facilities in the Northeast, Horseman, inflammatory phrase that will return to warns its clients against apologies that ad- DDS bite you in the fundament. So says the mit guilt — even in states that have laws insurance company; so agrees the entire protecting doctors who say they are sorry. ILLUSTRATION legal defense team. The concept of “not What! There are states that have such BY CHARLIE O. guilty” is so prevalent in today’s society laws? Yes! At least 27 states have passed HAYWARD with the decline in good manners and laws protecting doctors that allow them common courtesy, one might assume it to use the “S” word when things go wrong only surfaced during the turbulent ’60s. without having fear their words will be Not so. Way back in the beginning used against them in court. By extension, of medicine before Harvey and Jenner, this includes “I apologize.” That phrase is before Osler and Lister, before Welby viewed as an admission of guilt in legalese and McDreamy, professional use of “I’m just the same as it is in your marriage. sorry” has been a no-no. A basic canon of CONTINUES ON 529

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Trial lawyers, as you might expect, DR. BOB, CONTINUED FROM 530 As such, it is seldom, if ever, heard. It is are against anything ment to encourage doctors to promptly so difficult to utter that the last recorded and fully inform patients of errors in an instance of a physicians offering it was an they didn’t initiate effort to stave off lawsuits. At the same Egyptian doctor to the royal court who time the practitioners are warned never mistook tincture of asp venom for pow- themselves. to admit errors and to delete the words dered rhinoceros horn. He was promptly “mistake,” “fault,” and “negligence” from entombed in an embarrassingly cheesy the way things turned out, but in no way their vocabularies. Trial lawyers, as you pyramid while still pleading “’I’m sorry” to is this to be considered an apology for might expect, are against anything they the late pharaoh’s irate family. personally being the cause of that result. didn’t initiate themselves. It has become necessary for commis- If this seems to be treading a very fine It might be well for medical graduates eration to be more sharply defined. While line, it might be well to have an attorney finishing their residencies to seriously lawmakers in Rhode Island and seven present before you open your mouth. “The consider postponing practice until they more states are readying laws exempting devil made me do it,” is not considered a have completed the entire curriculum for a doctors who, in a freshet of impetuos- valid argument in a court of law except in law degree. Or, better yet, skip med school ity, recklessly confess they are sorry for certain remote villages in Tanzania. altogether and go straight to law. Lawyers something. “Sorry” is not in the same The medical industry is said to favor can say anything they want and only other boat with “apology.” You can be sorry for this wave of “I’m sorry” laws as a move- lawyers can understand them.

House

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