plants

and chemotherapy

complicatio

obert A. arr, DDS,a Donald C. Kramer, MS, DDS,b and ela EL Toth, MS, DDSC University of Texas M.D. Anderson Cancer Center, Department of Dental Oncology, Houston, Texas The cancer patient receiving chemotherapy often suffers severe oral complications related to the administration of antineoplastic drugs. Cancer patients who also have transmucosal or endosseous dental implants pose special problems for medical oncologists and dentists, both when planning for chemotherapy and when providing supportive care during the course of treatment. The relationship between dental implants and cancer chemotherapy is described and complications experienced by implant patients treated with chemotherapy at The University of Texas M.D. Anderson Cancer Center are reviewed. Recommendations on various aspects ement involving implant evaluation and the removal or retention of dental implants are discussed. (J PROSTHET DENT 1992;67:683-7.)

mplanta increase the retention and stability of prostheses for patients with compromised oral anatomy or function. As success rates for dental implants improve, increasing numbers of patients are having these devices used in their prosthodontic rehabi1itation.l Likewise, systemic chemotherapy has become increasingly important in the treatment of cancer. It was estimated that 557,000 patients received chemotherapy in 1989.2 Unfortunately,

with the use of cytotoxic

anticancer

drugs comes

adverse oral effects such as infection, hemorrhage, mucositis, and pain. 3s4 In addition to morbidity and mortality directly related to these complications, interruption or delay of chemotherapy because of such side effects can create equally serious sequela. The incidences of edentulism and cancer are age-related.jz 6 Given the aging U.S. population, it is logical to conclude that medical oncologists and dentists will be seeing more (and older) patients with cancer. More of these patients will be receiving chemotherapy and more will have dental implants-implants that will contribute to an increased incidence of oral complications if the patient is not managed correctly. ELATED

COMPLICATIONS

Six patients with dental implants have been seen in the Department of Dental Oncology at The University of Texas M.D. Anderson Cancer Center just before or during treatment with cytotoxic drugs. The presence of these implants czclsed problems both in planning and delivering chemo-

aDental Oncology Fellow. bDental Oncologist, Associate Professor of Dental Oncology, and Chief, Dental Oncology Training Programs. CDental Oncologist (Oral Pathology and General Dentistry) and Associate Professor of Dental Oncology. 10/P/35786

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therapy and in attempting to prevent or manage oral complications. Infectious complications occurred in four patients. Each had implants prone to fibrous encapsulation: three had subperiosteal or blade implants supporting fixed restorations, and one had blade implants supporting a combination of fixed and removable prostheses. The complications ranged from painful localized periimplant infections to numerous episodes of fever and to documented septicemia with organisms of the Streptococcus virielens group. Chemotherapy was delayed for 4 weeks in one patient when severe infection around subperiosteal implants required extensive surgery that resulted in oral-a&al fistulae. In another patient substantial mandibular bone was removed to free a failing blade implant. All four patients with infeetion exhibited bone loss, implant mobility, and signs and symptoms of chronic peri-implant disease. Hemorrhage and mucositis were associated. Two patients had implants that painfully abraded and then lacerated the atrophic oral mucosa, resulting in profuse bleeding. One patient had a mandibular staple implant and the other had endosseous root-form implants in the anterior mandible implants. These implants, both considered osseointegrated types, were not associated with infection. Chemotherapy was twice interrupted because of severe mucositis and hemorrhage caused by the root-form implants injuring the lip and tongue. In both patients the implants were abutments for complete dentures that were exposed when the prostheses were removed because of mucositis. A custom mouth guard could have prevented or reduced these complications. However, when the patients were referred, severe oral pain precluded making dental impressions. Utility wax, periodontal packing, soft denture relining material, light-polymerized acrylic resin and moist gauze were considered to cover the implants. Unfortu-

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nately, all of these coverings are either easily dislodged or involve painful tissue manipulation during placement and replacement when mucositis is present. All of the infectious, hemorrhagic, and mucosal complications followed the cytotoxic and myelosuppressive cycle induced by chemotherapy. Peri-implant infections were chronic and quiescent until local exacerbation, fever, and septicemia flared during periods of granulocytopenia. Similarly, oral bleeding became pronounced only when thrombocytopenia became profound. Sepsis may have been improved with systemic antibiotics, and control of hemorrhage was intermittently achieved with hemostatic agents and platelet transfusions. However, acute infection and bleeding subsided only with hematologic recovery. None of the six patients had prechemotherapy dental evaluation. Four patients (three of whom started therapy at other institutions) were not referred until oral complications arose. Two others were referred for “routine examination,” but only on the day before or the day after chemotherapy began. Two patients were hospitalized for 15 days before therapy was scheduled without being referred for dental evaluation. This lack of pretherapy assessment was unfortunate because preexisting dental conditions and potential sources of oral trauma could have been recognized and eliminated before therapy. All six patients also bad poor oral hygiene regardless of implant or prosthesis type. In five of the six patients, the initial attending physician made no note of the presence of implants. During historytaking, the patients themselves often did not mention having dental implants inserted. One patient related three other surgical interventions in her lifetime but omitted any reference to implant surgery. In three patients, oncologists were reluctant to initiate corrective dental care because cancer therapy might be delayed. During subsequent chemotherapy, these patients experienced significant episodes of oral infection, fever, and septicemia. AGEMENT

RECOMMENDATIONS

Proper management of a dental implant patient about to undergo chemotherapy requires that the implants either be removed before therapy or retained with protective care provided. This decision can only be made after clinical and radiographic examination by a dentist who has some understanding of cancer and its therapies, potential complications, and dental implants. E~al~~tio~

of implants

A precbemotherapy dental evaluation should be included in the preparatory medical workup when the patient often has unused hours waiting for test results and final reports. Definitive dental procedures may be provided to eliminate infections or hemorrhagic foci. If time or medical conditions will not permit treatment or if anticancer

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therapy has already started, the evaluation still provides baseline information that will allow the dentist to plan preventive and palliative measures for oral complications that arise. It is important to have a dentist with expertise in oncology perform the dental assessment. Inexperienced clinicians may be unaware of the sometimes crucial impact of apparently innocuous dental conditions. Physicians should not be expected to fully understand dental implants or their ramifications in patients about to receive cytotoxic drugs. They also may not realize that simple and expedient dental measures can greatly reduce the risk of implantrelated complications. When a patient with dental implants is referred for a prechemotherapy oral assessment, the dentist must first determine the status of the implants. Because scientific investigation has lagged behind empirical use, some uneertainty exists regarding the suitability of current dental methods for evaluating implants.7-g Controversy about implant serviceability is often based on exacting radiographic and clinical measurements, mathematical comparisons of various periodontal indices, histologic section or electron microscopic studies, and statistical analysis that has become necessary to prove or disprove the validity ofimplantsystem success. More realistically, the implant patient scheduled to receive cytotoxic chemotherapy faces a very real threat from any oral infection or less-than-optimal tissue condition. Bacteria associated with failing implants include St&~ylococcus aureus, Pseudomonas aeroginosa, KlebsielEa pneumonia, Enterobacter cloacae, Bacteroides sp., and spirochetes. Yeast infection has also been detected around failing implants.g Any of these can be opportunistic pathogens and cause dangerous septicemias in immunocompromised patients. The dentist must recognize any evidence of implant failure, realizing that early manifestations may be subtle. There is general agreement that peri-implant radiolucency, implant mobility, and signs and symptoms of pain and infection are the most frequently seen indications of implant failure.7, 8,lo-l2 To a lesser extent, paresthesia, violation of vital anatomical structures, persistent gingival inflammation, and other tissue abnormalities have also been cited as serious problems requiring implant removal.i2-i5 Although there has been no consistent agreement about the use of periodontal probing in the evaluation of implants, it is one method for assessingpotentially deleterious changes in the peri-implant environment. lo-i3 Dental implants with pocket depths of 6 mm should be removed. Some allowance can be made for implants penetrating unattached mucosa, as long as the supporting tissues are healthy and the area can be cleaned. Blade and subperiosteal implants that enter the antrum create a risk of fistulization and should be removed. However, some osseointegrated root-form implants may either penetrate the maxillary antrum without complication or be placed in proximity to the antrum after the floor is “raised” surgically. If a chemotherapy patient has implants of this type and they appear radiographically sound, are immobile, and have healthy surrounding tissue, they should be left in place. Removal would entail risk of sinus exposure.15 In the absence of further experience, implants that penetrate the nasal cavity should be managed in the same manner. After careful assessment of any dental implants present, the dentist must then decide on retention or removal. Surgical techniques have evolved to salvage or maintain failing implants. Normally, these methods are probably justifiable in light of the patient’s and practitioner’s investment.15However, because of the obvious urgency to proceed with cancer care, it is not realistic to expect an oncologist to defer chemotherapy for several weeks while a patient undergoes corrective dental surgery. When peri-implant infection can be eliminated by prophylaxis, curettage, or other minor local measures with complete healing achieved within 7 to 10 days, implants can be retained. In all other instances, it is strongly recommended that they be removed.

emoval

of implants

If surgical removal is planned, the oncologist must know the number of postoperative days to be allowed for oral healing before chemotherapy can safely begin. To properly advise the physician, the dentist must estimate the degree of difficulty that may be encountered in removing individual implants, taking into consideration tissue conditions and implant design. Any oral surgery should be performed as atraumatically as possible. Primary closure of the surgical site is beneficial. If closure cannot be achieved, figureeight sutures are helpful in retaining clots. Surgical packing for hemostasis should not be used unless absolutely necessary, as these materials may provide a nidus for infection. Antibiotic coverage should be commensurate with the degree of infection present and is required whenever an indwelling venous catheter is in place. The patient should be followed up closely until adequate wound granulation will permit the initiation of chemotherapy. In the event chemotherapy cannot be delayed to allow for removal of an implant associated infection, septic complications may be noted when myelosuppression occurs. If septicemia should become life-threatening, oral surgery may be necessary despite a cornpromised hematologic status. Such

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patients generally require coordinated medical support and are best managed on an inpatient basis.

Retention

of implants

If a decision is made to retain healthy dental implants, the dentist is responsible for (1) protection of the oral tissues and (2) implant hygiene. Tissue protection. Dental implants that are designed to support or retain removable prostheses may protrude from the mucosa and traumatize adjacent soft tissue. If implants are serving as an abutment for a fixed prosthesis, the artificial crowns are usually smooth and rounded enough to avoid tissue injury. However, if the fixed prosthesis bas been fractured or dislodged or has not yet been placed over the implants, the potential for trauma remains. If the implant superstructure can be detached from the submucosal component, the potential for tissue injury may be reduced. If the implant superstructure cannot be detached easily or completely, a protective covering is needed. Some root-form implants have smooth-surfaced caps or cover screws that are used after abutment connection. If these are available and can be manipulated into position, they may be adequate. However, the best protection would be a soft custom mouth guard made prior to chemotherapy. The technique for providing such a mouth guard is not difficult and has been described.16 Efficacious use of the mouth guard must begin before painfE1 chemotherapy-induced mucositis. Wearing existing dentures over exposed implants might be considered a way to protect oral tissues when there is risk of mucositis. Unfortunately, most patients cannot wear removable prostheses when painful oral ulcerations are present. Also, if a denture is ill-fitting, it may cause tissue injury, bleeding, and infection during myeiosuppressive chemotherapy. Even well-fitting dentures can abrade the compromised oral mucosa, and all oral prostheses are fomites for pathogenic organisms. Tissue-conditioners or resilient denture liners may allow a faulty denture to be used over an exposed implant. However, these materials must be changed frequently or they become an irritant and a focus for microbial growth. It is often difficult to change the material every few days. Using permanent relining, material or making a new denture might also ‘be options. Unfortunately, during chemotherapy there are often changes in the denture-bearing structures tbat are not reversible when treatment is completed. These changes may be due to rapid weight loss resulting from disease-related cachexia and therapy-related anorexia. Dentures that are initially well-adapted can quickly become unstable or nonretentive and lead to complications. In addition, time constraints rarely allow for fabrication of new dentures before chemotherapy begins, and patients can bave a host of problems if this is attempted during chemotherapy. Missed appointments because of malaise and illness and less-than-

686

XWRR,

optimal impressions or jaw relationship records due to nausea, vomiting, or mucositis will invariably lead to poor prosthodontic results. These procedures should be deferred when the patient is receiving chemotherapy. Implant hygiene. It is important that a high level of oral hygiene be maintained during chemotherapy. The accumulation of plaque and calculus around implants can lead to infection, pain, and bleeding in immunocompromised patients. The dentist must educate the patient on the importance of hygiene. The patient must have the ability and the commitment to maintain meticulous oral hygiene. Compliance may be unlikely in view of previous lack of interest. Malaise and oral discomfort also make it difficult to maintain acceptable oral hygiene during chemotherapy, and implant prostheses may be difficult to clean. The dentist must recommend simple yet efficient hygiene methods, instruct the patient in their proper use, and closely follow up, aid, and encourage the patient during periods of difficulty. A variety of measures for maintaining peri-implant hygiene and gingival health have been advocated, including the use of sulcular, interdental, and rotary brushes, and dental flos~.~,15,I79l8 If mechanical plaque control is ineffective, chlorhexidine with an irrigator has been recommended.3 Other antimicrobial adjuncts to home care include stannous fluoride, tetracyclines, and metronidazole.i5 Any use of antibiotics for dental purposes during chemotherapy should be discussed with the oncologist. Oral hygiene measures may require modification if a patient become severely myelosuppressed or suffers from extensive mucositis. Mechanical cleaning methods may elicit bacteremia or bleeding in granulocytopenic and thrombocytopenic patients. Even the use of an irrigator can cause transient bacteremia. The patient may be limited to the use of extra-soft toothbrushes or sponge-tipped swabs. If severe mucositis is present, the alcohol content of chlorhexidine and the acidic pH of stannous fluoride may not be tolerable. Dilutions of chlorhexidine (1:l ratio) or hydrogen peroxide (1:5 ratio) with water may be acceptable. If not, a mild saline or bicarbonate solution is suggested until the mucosa heals.

At M. D. Anderson Cancer Center, patients treated with antineoplastic drugs who also had dental implants experienced complications of infection, pain, tissue injury, and hemorrhage directly related to the implants. With the increasing use of both dental implants and cancer chemotherapy, dentists invariably will seemore patients with oral and systemic complications because of the presence of implants. Because a preventive approach is the most cost-effective in all regards, it is imperative that dental evaluation be the standard of care before chemotherapy is administered. The examining dentist should be knowledgeable

686

XRAMEB,

AND

TOTH

about the interrelationship between oral conditions and oncologic disease and therapy. When making treatment decisions regarding dental implants that are already in place, the dentist must realize that patients will periodically be myelosuppressed and immunocompromised. Esoteric distinctions as to which evaluation parameters truly indicate implant success or failure serve little purpose when the individual is at great risk from any oral infection or trauma. Implants that exhibit clinical or radiological evidence of infection to a degree that cannot be quickly eliminated by simple dental procedures should be removed. When removal of implants is in order, the dentist must advise the oncologist of the time needed for both the surgery and an adequate healing period. If time will not permit removal of an infected implant before cbemotherapy begins, supportive care should be provided as necessary. Implants that will remain in place during chemotherapy should be evaluated for their potential to abrade atrophic oral tissues. It is preferable to fabricate a custom mouthguard to cover exposed implant components during these periods. If dental implants are to be retained, the patient must understand and be committed to stringent implant hygiene during chemotherapy and close follow-up thereafter. During a 1986 American Dental Association panel discussion on the status of dental implants, it was stated that it would be important to discover whether implant patients undergoing chemotherapy would have special complications or management problems.ig In our experience, these patients do develop complications, frequently of a serious nature. However, it is also apparent that both major and minor problems related to dental implants could be greatly reduced or eliminated with proper prechemotherapy evaluation and interceptive management.

REFERENCES 1. National Institutes of Health Consensus Development Conference statement: dental implants. J Am Dent Assoc 1988;117:509-12. 2. DeVita VT Jr. Principles of chemotherapy. In DeVita VT Jr, Hellman S, Rosenberg SA, eds. Cancer: principles and practice of oncology, vod 1. 3rd ed. Philadelphia: JB Lippincott, 1989:276-300. 3. Dreizen S, Bodey GP, Rodriquez V. Oral complications of cancer chemotherapy. Postgrad Med 1975;58:75-82. 4. Toth BB, Frame RT. Dental oncology: the management of disease and treatment related oral/dental complications associated with chemotherapy. Current Problems in Cancer 1.983;7:7-35. 5. Meskin LH, Brown LJ. Prevalence and patterns of tooth !oss in U.S. employed adult and senior populations, 1985-86. J Dent Educ 1988;52:686-91. 6. Newell GR. Epidemiology of cancer. In DeVita VT Jr, Hellman S, Rosenberg SA, eds. Cancer: principles and practice of oncology, ~011. 2nd ed. Philadeiphia: JB Lippincott, 1985:151-95. 7. Shulman LB, Rogoff GS, Savitt ED, Kent RL. Evaluation in reconstructive implantology. Dent Clin North Am 1986;30:327-49. 8. Cox JF, Zarb GA. The longitudinal clinical efikacy of osseointegrated dental implants: a 3-year report. Int J Oral Maxillofac Implant 1987; 2:91-100.

9. Newman MG, Flemmig TF. Periodontal considerations of implants and implant associated microbiota. J Dent Educ 1988;52:737-44. 10. Meffert RM. Endosseaus dental implantology from the periodontist’s viewpoint. J Periodontol 1986;57:531-6. 11. Shulman LB. Surgical considerations in implant dentistry. J Dent Educ 1988;52:712-20. 12. Albrektsson T, Zarb G, Worthington P, Eriksson A. The long-term efficacy of currently used dental implants: a review and proposed criteria of success. Int J Oral Maxillofac Implants 1986;1:11-25. 13. Schnitman PA, Schulman LB. Recommendations of the Consensus Development Conference on Dental Implants. J Am Dent Assoc 1979; 98:373-7. 14. Kreutz RW, Carr SJ. Bilateral oronasal fistulas secondary to an infected maxillary subperiosteal implant: report of a case. Oral Surg Oral Med Oral Path01 1986;61:230-2. 15. Gammage DD, Bowman AE, Meffert RM. Clinical management of failing dental implants: four case reports. J Oral ImplantolI989;15:124-31.

rajectory

surgical

Eric D. Adrian, DMD,a John William A. Krantz, DDSC U.S. Army DENTAC, Atlanta, Ga.

16. Yard RA, Netti CA, Bender PJ. Dental implant night guard. J PROSTHE~DENT 1987;58:71l. 17. Maxson B, Sindet-Pedersen S, Tideman II, Fonseca RJ, Zijlstra 6. Multicenter follow-up study of the transmandibular implant. J Oral Maxillofac Surg 1989;47:785-9. 18. Meffert RM. The soft tissue interface in dental implantology. J Dent Educ 198&52:810-l. 19. Kapnr KK. Emphasis. Advances in dentistry: implants. J Am Dent Assot 1986;113:872-9. Reprint requests to: DR. DONALDKRAMER DEPT.• FDENTALONCOLOGY,BOX~ UNI~.OFTE~ASM.D.ANDERSONC.~N~ERCENTER ~~~~HOLCOMBEBLVD. HOUSTON,TX 77030

guide stent for implant R. Ivanhoe,

DDS,b

Fort Gordon, Ga., and Emory University,

placeme

and School of Postgraduate

Dentistry,

This article describes a new implant placement surgical guide that gives both implant location and trajectory to the surgeon. Radiopaque markers are placed on diagnostic dentures and a lateral cephlometric radiograph is made that shows the osseous anatomy at the symphysis and the anterior tooth location. The ideal implant location and trajectory data are transferred to a surgical stent that programs the angle and location of the fixtures at time of surgery. The stent has the additional benefit of acting as an occlusion rim, a mouth prop, and tongue retractor. Use of this stent has resulted in consistently programming the placement of implant fixtures that are prosthodontically ideal. (J PROSTHET DENT 1992;67:68791.)

he success of any implant system is highly dependent on the degree of cooperation between the surgeon placing the implants and the prosthodontist constructing the prosthesis. Lack of communication may result in fixture placement that compromises esthetics and function and may not be usable. The prosthodontist should treatment plan the proposed implant patient and convey to the

The opinions or assertions contained herein are those of the authors and are not to be construed as official or as reflecting the views of the Department of the U.S. Army. aLieutenant Colonel, U.S. Army, DC, Assistant Chief, Removable Prosthodontic Service, Fort Gordon, Ga. bAssociate Professor, Department of Prosthodontics, Emory University, School of Postgraduate Dentistry. cColonel, U.S. Army, DC; Chief, Removable Prosthodontic Service, Fort Gordon, Ga. 10/1/3x362

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surgeon (I) the type of final restoration, fixed or removable, (2) the number and approximate location of the fixtures, and (3) the fixture angulation. Various stents have been suggested to aid the surgeon, but many have proved impractical.1-4 ing protruding pins as paralleling guides interfere with rotary instrumentation and cannot provide placement guidance in the mouth-open, surgical position. Stems using holes to locate fixtures5 are impractical because they give the surgeon no leeway in buccal-lingual placement to avoid mandibular concavities, and they give no angular information. In frustration, surgeons have resorted to “eye-balling” fixture placement relative to the maxillary anterior ridge, which often leads to lingually tipped fixtures. Tbe angle between a line drawn from the anterior maxillae to the mandibular ridge becomes more acute as the mandible is opened. This change in angulation tends to lead the

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