dental procedures and subsequent prosthetic joint infections …€¦ · an endodontist, who also...

29JADA Middle East vol 3 No 2 Mar-Apr 2012 54 JADA Middle East vol 2 No 5 Sep-Oct 2011

Neuralgia-inducing cavitationalosteonecrosis A possible diagnosis for an orofacial pain complaint?

Gary D. Klasser, DMD; Joel B. Epstein, DMD, MSD, FRCD(C)

JADA 142(6) http://jada.ada.org June 2011 651

A45-year-old woman visited her generaldentist because of severe pain in theright mandibular posterior region. Herfirst molar contained a large mesial-

occlusal-distal amalgam restoration, and thepatient experienced symptoms consistent withirreversible pulpitis. In addition, radiographsshowed changes associated with the mesial root.The second molar contained a conservativeocclusal amalgam restoration, and the premo-lars contained no restorations. The clinicianperformed endodontic therapy in the patient’sfirst molar; the pain remitted for a few weeksafter treatment but then returned.

The dentist performed endodontic treatmentagain in the first molar, which resulted in nochange in the patient’s pain. He referred her toan endodontist, who also treated the toothendodontically, then performed an apicoectomyand a retrograde sealing of the tooth. Again, thepatient experienced short-term pain relief, butowing to pain recurrence, the patient’s generaldentist extracted the tooth.

The patient continued to experience pain, andher general dentist performed endodontic treat-ment in the second molar. However, the pain per-sisted. The dentist referred her again to theendodontist, who concluded that the second pre-molar was the source of the pain and performedendodontic therapy in that tooth. Subsequently,the patient’s general dentist extracted the secondpremolar and second molar, but the pain con-tinued. The patient later sought care from hergeneral dentist for persistent severe pain in theedentulous right side of the posterior mandible.

Did this patient experience the phenomenonknown as neuralgia-inducing cavitationalosteonecrosis (NICO), or did her pain complaintrepresent another orofacial pain condition?

EXPLANATIONReview of NICO concepts. Ischemicosteonecrosis (literally “dead bone from poorblood flow”) is a condition reported in the ortho-pedic literature as not being a true bone dis-ease. Instead, researchers believe it is a resultof systemic and local disorders or events thatultimately lead to ischemia and infarction ofbone marrow, bone or both.1,2 Proponents ofNICO have extended similar concepts to themaxillofacial region with the claim thatosteonecrosis can occur in the maxilla and man-dible as a result of trauma and infection. Forexample, Bouquot and McMahon3 reported thata patient with NICO might have experiencedpulpal, periodontal or sinus infections; under-gone tooth extractions, endodontic procedures orperiodontal surgeries; experienced blows to thefacial region; received vasoconstrictors duringprocedures involving administration of localanesthetics; or a combination of these.

In the 1840s, Bond4 explored concepts relatedto maxillofacial osteonecrosis, which Noel5 latertermed “bone caries.” Other practitioners haveused terms such as “bone cavities” to describeconditions associated with bone destruction, butwithout inflammatory signs.6-8 These bone cavi-ties often were located in old extraction sitesand were accompanied by neuralgialike pain.6-8

Ratner and colleagues9 expanded this conceptby reporting that these lesions usually were notdetectable radiographically and that the eti-

CLINICAL PROBLEM

P A I N U P D A T EC L I N I C A L P R A C T I C E

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To Add On page 12 add: © 2011 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 2, 24-125 On page 16 add: © 2011 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 2, Page 137-149 On page 30 add: © 2011 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2010, Volume 141, No 10, Page 1250-1256 On page 38 add: © 2010 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 2, Page 194-195 On page 41 add: © 2011 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 1, Page 66-68 On page 45 add: © 2011 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 2, Page 150-158 On page 55 add: © 2010American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 1, Page 53-56 On page 60 add: © 2010American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 2, Page 170-172 On page 63 add: © 2010American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 1, Page 88-90 On page 66 add: © 2010American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 1, Page 111 10 JADA Middle East vol 2 No 2 March-April 2011

To Add On page 12 add: © 2011 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 7, Page 790-792 On page 20 add: © 2011 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 6, Page 612-620 On page 30 add: © 2011American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 6, Page 658-665 On page 39 add: © 2011 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 6, Page 668-671 On page 43 add: © 2011 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 6, Page 635-645 On page 55 add: © 2011 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 6, Page 651-653 On page 58 add: © 2011 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 6, Page 654-656 On page 62 add: © 2011 American Dental Association. Republished by Medical Online Publication SAL with permission of American Dental Association. All rights reserved. JADA 2011, Volume 142, No 6, Page 646-650 10 JADA Middle East vol 2 No 4 July-August 2011

Debate continues con-cerning the need forantibiotic prophylaxisto prevent patients

from developing prostheticjoint infections (PJIs) afterundergoing dental pro-cedures. The 2009 AmericanAcademy of Orthopaedic Sur-geons’ (AAOS’) recommendedthat clinicians consider pre-scribing antibiotic prophy-laxis for all patients who haveundergone total joint arthro-plasty before those patientsundergo any invasive pro-cedures that may cause bac-teremia, regardless of thetime since joint implantation,because of the potential foradverse outcomes and cost oftreating PJIs.1 The AAOSstatement did not define inva-sive dental procedures thatfrequently produce a tran-sient bacteremia. Previousstatements promulgatedjointly by the AAOS and theAmerican Dental Association2,3

(ADA) did not advocate thatclinicians consider prescribingantibiotic prophylaxis forinvasive dental proceduresthat are associated with ahigh incidence of bacteremiatwo years after the patienthas had total joint arthro-plasty, except for patients

Dr. Skaar is an assistant professor, Department of Developmental and Surgical Sciences, School of Dentistry, University of Minnesota, 7-368 Moos HealthSciences Tower, 515 Delaware St. SE, Minneapolis, Minn. 55455, e-mail “[email protected]”. Address reprint requests to Dr. Skaar.Ms. O’Connor is a research fellow, Division of Health Policy and Management, School of Public Health, University of Minnesota, Minneapolis.Dr. Hodges is an associate professor, Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis.Dr. Michalowicz is a professor and holder of the Erwin Schaffer Chair in Periodontal Research, Division of Periodontology, Department of Developmentaland Surgical Sciences, School of Dentistry, University of Minnesota, Minneapolis.

Dental procedures and subsequentprosthetic joint infectionsFindings from the Medicare Current Beneficiary Survey

Daniel D. Skaar, DDS, MS, MBA; Heidi O’Connor, MS; James S. Hodges, PhD; Bryan S. Michalowicz, DDS, MS

A B S T R A C TBackground. The publication of the 2009 AmericanAcademy of Orthopedic Surgeons’ (AAOS’) guidelines forantibiotic prophylaxis after joint replacement (arthro-plasty) has renewed debate concerning appropriate pro-phylaxis for dental patients. The authors examined anadministrative data set to assess whether dental procedures were asso-ciated with prosthetic joint infections (PJIs). Methods. Using data for the years 1997 through 2006 from theMedicare Current Beneficiary Survey (MCBS), the authors identified par-ticipants who had undergone total joint arthroplasty and those who hadexperienced a PJI. They explored associations between dental proceduresand subsequent PJIs by using time-to-event analyses (N = 1,000). Anested case-control study included case participants who had had PJIs (n = 42) and matched control participants who had had total arthroplastybut had no PJIs (n = 126). The authors calculated hazard ratios (HRs) and odds ratios (ORs). Results. Control participants (people without PJIs) were more likelythan were case participants (those with PJIs) to have undergone an inva-sive dental procedure, though this trend was not statistically significantin either the time-to-event analysis (HR = 0.78; 95 percent confidenceinterval [CI], 0.18-3.39) or the case-control analysis (OR = 0.56; 95 percentCI, 0.18-1.74). Only four of 42 case participants had undergone an inva-sive dental procedure in the 90 days before the infection occurred. Consid-eration of all dental procedures yielded similar results. Conclusions. Dental procedures were not associated significantly withsubsequent risk for PJIs, although this study’s power was somewhat low.The clinical importance of prophylactic antibiotics in dentistry for patientswho have undergone joint arthroplasty, therefore, may be questioned. Clinical Implications. These results support the view that the 2009AAOS Information Statement on antibiotic prophylaxis for people withprosthetic joints should be reconsidered for patients in that populationwho are receiving oral health care. Key Words. Prosthetic joint arthroplasty; prosthetic joint infection;antibiotic prophylaxis; dental procedures.JADA 2011;142(12):1343-1351.

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with any of the following conditions:dthose who are immunocompromised;dthose who have had a previous prostheticjoint infection;dthose who have high-risk comorbidities.

The AAOS statement has been criticized4-6

for its lack of input from organized dentistryand its reliance on several assumptions: dPJIs can arise from dental procedures thatinduce bacteremias associated with oral flora; da temporal relationship exists between dental procedures and PJI; dantibiotic prophylaxis may prevent dentalprocedure–related bacteremias and subse-quent PJIs; dcomparisons between late PJI and infectiveendocarditis are questionable because of dif-fering anatomy, blood supply, microorganismsand infection mechanisms.

More than 750,000 total joint arthroplastiesare completed annually in the United States;about 7 percent of these are revisions involvingthe replacement of existing prosthetic joints.7

Given the aging U.S. population, the demandfor primary and revision total hip and kneearthroplasties is expected to rise substantially.Between 2005 and 2030, Kurtz and colleagues8

projected, the number of primary total hiparthroplasties will increase an estimated 174percent to 572,000 cases annually and thenumber of total knee arthroplasties will in -crease an estimated 673 percent to 3.48 million.During this period, Kurtz and colleagues8 esti-mated, the total number of hip and knee revi-sions will grow by 137 percent (96,700 casesannually) and 601 percent (268,200 cases annu-ally), respectively. In addition to patient mor-bidity, the financial burden of revision arthro-plasties is substantial. Medical costs alone forrevision procedures have been estimated to be4.8 times higher than the costs for primary jointarthroplasties.9

The need for antibiotic prophylaxis for pa -tients who have undergone total joint arthro-plasty has been debated at length without producing a consensus.10 Previous recommenda-tions have been based on relatively limiteddata,11-13 and several authors have questionedthe need for antibiotic prophylaxis because ofthe lack of supporting data.14,15 The 1997 and2003 ADA/AAOS advisory statements attemptedto clarify clinical decision making by providingguidelines to assist dentists in determiningwhich patients undergoing which dental pro-cedures could benefit from antibiotic prophy-laxis and by providing appropriate antibioticregimens.2,3 The 2009 AAOS statement appears

contrary to some of the previous recommenda-tions and has created confusion and uncertaintyfor oral health care providers treating patientswho have a history of total joint arthroplasty.

To address the renewed controversy sur-rounding the need to provide antibiotic prophy-laxis before dental procedures to prevent PJI,we used a nationally representative administra-tive data set—that from the Medicare CurrentBeneficiary Survey (MCBS), which is sponsoredby the Centers for Medicare and Medicaid Serv-ices16 (CMS)—to assess the prevalence of totaljoint arthroplasty and PJIs in adults seekingoral health care. We also aimed to test for asso-ciations between dental procedures and PJIs.With the recent finding that high- and low-riskdental procedures were not associated with PJIsin a tertiary care hospital,17 we hypothesizedthat dental procedures, including invasive onesassociated with a higher risk of experiencingbacteremia, were not associated with an in -creased risk of developing PJIs in a nationallyrepresentative sample of Medicare beneficiarieswho are aged or have disabilities.

METHODSThe MCBS is an annual, continuous, nationallyrepresentative survey of the U.S. Medicare pop-ulation that includes all beneficiaries 65 yearsand older and people with disabilities youngerthan 65 years.16 The data are collected from theCMS Medicare enrollment file and disseminatedby WESTAT (Rockville, Md.). The MCBS filegives a continuous, complete profile of demo-graphic characteristics, health care and dentalservice utilization, health outcomes and pre-scribed drugs. The survey’s rotating paneldesign allows approximately 12,000 participantsto be interviewed three times annually for up tofour consecutive years. Approximately 4,000participants exit the study annually because ofdeath, refusal to participate and rotation out ofthe survey; they are replaced. For this study, weanalyzed data from the 1997-2006 MCBS Costand Use files for community-dwelling benefici-aries.16 Given that the MCBS is a deidentifiedpublic data set, the University of MinnesotaInstitutional Review Board determined that thestudy protocol was exempt from review.

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ABBREVIATION KEY. AAOS: American Academy ofOrthopaedic Surgeons. ADA: American Dental Asso-ciation. CMS: Centers for Medicare and MedicaidServices. ICD-9-CM: International Classification ofDiseases (Ninth Revision, Clinical Modification). JR: Joint replacement. LRD: Last relevant date.MCBS: Medicare Current Beneficiary Survey.PJI: Prosthetic joint infection.


31JADA Middle East vol 3 No 2 Mar-Apr 2012


We used data forthe years 1997through 2006, datathat described dentalvisits and procedures,inpatient hospitaliza-tion for joint replace-ments and infections,antibiotic prescrip-tions and sociodemo-graphic characteris-tics. We identifiedinpatient hospitalization procedure codes,including total joint arthroplasty and infection,according to diagnostic codes from the Interna-tional Classification of Diseases, Ninth Revi-sion, Clinical Modification18 (ICD-9-CM) (Table1). Dental procedures recorded in the surveyinclude radiographs, teeth cleaning, exami-nations, restorations (called “fillings” in theMCBS), extractions, endondontic procedures(called “root canals” in the MCBS), crowns,bridges and complete and removable dentures,orthodontics and other services. The surveyincluded periodontal procedures in the “teethcleaning” category. We designated as invasivethe following procedures: teeth cleanings,extractions and endodontic procedures. Theseprocedures frequently involve “manipulation ofgingival tissue or the peri-apical region of teethor perforation of oral mucosa,” as described inthe 2007 American Heart Association guidelinesregarding procedures likely to result in bac-teremias.19 We considered all other procedures,including restorations, to be noninvasive. Anti -biotic prescriptions for drugs commonly pre-scribed for joint prophylaxis (such as oral amox-icillin, cephalexin, cephradine and clindamycin)were recorded in the survey according to brandand generic names.

We used two approaches to test for associa-tions between demographic variables, dentalprocedures and PJIs. First, we identified allparticipants who had undergone total jointarthroplasty while they were enrolled in thesurvey, some of whom experienced a subsequentPJI. We conducted time-to-event analyses todetermine if having a dental procedure in thepreceding 90- and 180-day periods was asso-ciated with PJI. We considered dental-visitstatus a time-varying covariate (predictor)because a participant’s status—that is, whetherhe or she had undergone a dental procedure inthe preceding 90 or 180 days—changed acrosstime. We considered each dental procedure andthe designated invasive dental procedures indi-vidually. Thus, we performed four time-to-event

analyses, considering any dental procedure per-formed in the preceding 90 days and 180 daysand considering only invasive dental proceduresperformed in the same periods. Because of thesmall number of PJI events recorded in thiscohort (see the Results section), our adjustedtime-to-event analyses included only a singleadjuster at a time, either education (12 years orless versus more than 12 years), age in years, orscore on the Charlson comorbidity index.20 Thisvalidated, weighted index is used widely; it isbased on a number of comorbid medical condi-tions of increasing severity. Investigators use itin longitudinal studies to predict mortality risk.We calculated hazard ratios (HRs), computed inthe natural log scale and back-transformed, fordental visits versus no dental visits in the pre-ceding periods.

Next, we conducted a nested case-controlanalysis after identifying all participants whohad experienced a PJI in the 10-year surveyperiod. This included participants in the time-to-event analyses in addition to those who expe-rienced a PJI while in the survey but who hadundergone total joint arthroplasty at some inde-terminable time before entering the survey. Weselected three participants who did not have aPJI as controls for each case participant. Con-trol participants had undergone total jointarthroplasty while taking part in the surveyand were matched to case participants accord -ing to age groups (0-44, 45-64, 65-69, 70-74, 75-79, 80-84 and 85 years or older), sex andnumber of comorbid conditions (which wedefined arbitrarily as four or fewer or more thanfour). We compared case and control partici-pants according to receipt of any dental pro-cedure and any invasive dental procedure in the90 and 180 days before the last relevant date.The last relevant date for case participants wasthe date of the reported PJI and for control par-ticipants was their date of death or Dec. 31 ofthe last year in which they were enrolled in thesurvey. We compared the receipt of dental pro-cedures (any or none) during the preceding

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TABLE 1

ICD-9-CM* joint replacement and infectiondiagnosis codes.PROCEDURE OR DIAGNOSIS ICD-9-CM PROCEDURE OR

DIAGNOSIS CODES

Joint Replacement 81.5, 81.51, 81.52, 81.54, 81.56,81.57, 81.80, 81.81, 81.84, 81.9

Infection and Inflammatory Reaction Due toInternal Prosthetic Device Implant and Graft

996.66

* ICD-9-CM: International Classification of Diseases, Ninth Revision, Clinical Modification.18


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periods of interest between case and control par-ticipants by using Mantel-Haenszel tests strati-fied by groups formed by a case participant andhis or her three matching control participants.We considered P values of less than .05 to besignificant.

RESULTSParticipants who underwent total jointarthroplasty while enrolled in the MCBS.For the years 1997 through 2006, 1,000 partici-pants (358 men, 642 women) underwent pri-mary total joint arthroplasty surgery while par-

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TABLE 2

Characteristics of Medicare beneficiaries with primary joint replacement(JR) procedures and subsequent prosthetic joint infections (PJIs).PARTICIPANT CHARACTERISTIC NO. (PERCENTAGE) OF BENEFICIARIES, ACCORDING TO CONDITION

With JR(n = 1,000)

With JR and Subsequent PJI (n = 18)

With JR but WithoutSubsequent PJI (n = 982)*

Age (in Years)Younger than 65 66 (6.6) 2 (11.1) 64 (6.5)65 to 74 359 (35.9) 6 (33.3) 353 (36.0)75 to 84 412 (41.2) 7 (38.9) 405 (41.2)85 or older 163 (16.3) 3 (16.7) 160 (16.3)

SexMale 358 (35.8) 12 (66.7) 346 (35.2)Female 642 (64.2) 6 (33.3) 636 (64.8)

RaceWhite 905 (90.5) 16 (88.9) 889 (90.5)Nonwhite 95 (9.5) 2 (11.1) 93 (9.5)

Income0 to $25,000 582 (58.2) 14 (77.8) 569 (57.9)$25,001 or more 418 (41.8) 4 (22.2) 413 (42.1)

EducationHigh school graduate or less 639 (63.9) 14 (77.8) 625 (63.6)More than high school 361 (36.1) 4 (22.2) 357 (36.4)

Marital StatusNot married 498 (49.8) 7 (38.9) 491 (50.0)Married 502 (50.2) 11 (61.1) 491 (50.0)

Census Bureau Region of Residence†

Northeast 150 (15.0) 1 (5.6) 149 (15.2)Midwest 284 (28.4) 6 (33.3) 278 (28.3)South 375 (37.5) 6 (33.3) 368 (37.5)West South Central 182 (18.2) 4 (22.2) 179 (18.2)Puerto Rico 9 (0.9) 1 (5.6) 8 (0.8)

Self-Reported HealthExcellent/Very good/Good 691 (69.1) 11 (61.1) 679 (69.1)Fair/Poor 284 (28.4) 7 (38.9) 278 (28.3)Data missing/Unknown 25 (2.5) 0 (0.0) 25 (2.5)

Number of Comorbid ConditionsNone to three 580 (58.0) 11 (61.1) 568 (57.8)Four or more 393 (39.3) 7 (38.9) 387 (39.4)Data missing/Unknown 27 (2.7) 0 (0.0) 27 (2.7)

Charlson Comorbidity Index Score‡

0 18 (1.8) 0 (0.0) 18 (1.8)1 to 3 560 (56.0) 12 (66.7) 548 (55.8)4 or higher 398 (39.8) 6 (33.3) 392 (40.0)Data missing/Unknown 24 (2.4) 0 (0.0) 24 (2.4)

* Of these 982 participants in the Medicare Current Beneficiary Survey, 404 were followed for less than one year after undergoing arthroplasty,320 were followed for one to less than two years and 258 were followed for two to less than three years.

† Source: U.S. Census Bureau.21

‡ Source: Charlson and colleagues.20


33JADA Middle East vol 3 No 2 Mar-Apr 2012


ticipating in the MCBS. Two participants exper -ienced a PJI before undergoing arthroplastywhile enrolled in the survey, which indicatedthat they had entered the survey with a pros-thetic joint. We included these two participantsin the time-to-event analysis, with their “clock”starting at the date of the arthroplasty recordedin the MCBS data set; neither participant had asubsequent PJI recorded during the MCBS.

Among the 1,000 participants, 468 hadreceived hip prostheses, 501 had received kneeprostheses and 31 had undergone replacement ofanother joint. Eighteen of these people experi-enced a subsequent PJI while taking part in thesurvey (1.8 percent; 95 percent confidence in -terval [CI], 1.0 percent-2.6 percent). The per-centage of participants who had experienced aPJI was similar for those who reported havinghad a dental visit after undergoing total jointarthroplasty (seven of 457 [1.5 percent]; 95 per-cent CI, 0.4 percent-2.7 percent) and those whodid not (11 of 543 [2.0 percent]; 95 percent CI, 0.8percent-3.2 percent). Table 2 lists selected demo-graphic and dental visit characteristics for par-ticipants who had undergone a total joint arthro-plasty while taking part in the MCBS and forthose who subsequently had experienced a PJI.

Case and matched control participants.Overall, 42 PJIs were recorded in the MCBSdataset. This total includes the 18 participantswho experienced a PJI after undergoing totaljoint arthroplasty while they were enrolled inthe MCBS and 24 who underwent arthroplastybefore entering the survey (two of whom experi-enced a PJI and follow-up arthroplasty whilethey were enrolled in the survey). Table 3 pro-vides characteristics of the 42 case and 126matched control participants without PJIs,including basic demographic information suchas age, sex, education and U.S. Census Bureau21

region of residence as well as the number ofcomorbid conditions and their scores on theCharlson comorbidity index.20

Time-to-event analyses involving 1,000participants who had undergone totaljoint arthroplasty. Prior dental procedureswere not associated with PJI. HRs for pro-cedures performed within 90 or 180 days beforethe PJI were not significant (Table 4, page1349). HRs were less than 1.0 for all dental pro-cedures and invasive procedures, indicatingthat participants reporting having undergoneany dental procedure in the preceding periodwere less likely to experience a PJI than werethose who did not report having undergone adental procedure. None of the HRs were statisti-cally significantly different from 1.0. Adjust-

ment for individual characteristics did notchange the results appreciably (Table 4).

Case-control analyses. Only four case par-ticipants had undergone invasive dental pro-cedures in the 90-day period preceding the PJI.In the same years in which they experiencedtheir PJIs, all four of these participants receivedan antibiotic typically used for prophylaxis, al -though the date of their receipt of the antibioticis unknown.

Of the 42 participants with a PJI, 20 hadtheir PJI at least one year after total jointarthroplasty or entry into the survey; eightexperienced their PJI at least two years afterundergoing arthroplasty or entering the study.Of these 20 “late” infections (defined here asoccurring two or more years after joint arthro-plasty), five participants underwent a dentalprocedure and two underwent an invasivedental procedure in the 90 days before the PJIdeveloped. Both participants who reportedhaving undergone an invasive procedure had aprescription for an antibiotic appropriate forprophylaxis during the year of the invasivedental procedure (data not shown).

Four of 42 case participants (9.5 percent) and20 of 126 control participants (15.9 percent) hadundergone an invasive dental procedure in the90 days preceding the PJI (for case participants)or study exit (for control participants) (Table 5,page 1350). For each of the comparisons shownin Table 5, the estimated odds ratio (OR) wasless than 1.0, indicating that case participantswere less likely than control participants tohave undergone dental procedures, although not significantly so.

DISCUSSIONWe hypothesized that dental procedures werenot associated with risk for PJI. The results ofthe time-to-event analyses showed no signifi-cant associations between participants’ dentalvisits and PJIs in the 90 and 180 days precedinga PJI. The comparisons of case and control par-ticipants according to dental visits or invasiveprocedures experienced 90 and 180 days beforePJI or survey exit showed that participants inthe control group were more likely to have haddental visits involving any procedure and in -volving more invasive procedures, although notsignificantly so. We used similar analyses (datanot shown) to measure the association betweencase-control status and occurrence of dentalvisits at any time between entry into the studyor joint replacement (whichever occurred later)and either the infection or exit from the studyand to measure the association between case-

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control status and the rate of dental visits. Allanalyses yielded similar results: either no asso-ciation at all or a nonsignificant trend for con-trol participants to have had more dental visits.Although none of these findings individuallyrules out the possibility that dental proceduresare risk factors for PJIs, the evidence was con-sistent and does not support the hypothesis thatdental procedures are a common cause of or

even associated with PJIs. Given an aging U.S. population with in -

creasing demand for prosthetic joint arthroplas-ties as well as the substantial morbidity andtreatment costs associated with PJI, it is appro-priate that the AAOS periodically review andupdate antibiotic prophylaxis guidelines.8,9

Although the 2009 AAOS1 Information State-ment recommended only that health care

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TABLE 3

Selected characteristics of prosthetic joint infection case participantsand age-, sex- and medical comorbidity–matched control participants.PARTICIPANT CHARACTERISTIC NO. (PERCENTAGE) OF CASE

PARTICIPANTS (n = 42)NO. (PERCENTAGE) OF MATCHED

CONTROL PARTICIPANTS (n = 126)*

Age (in Years)Younger than 65 5 (11.9) 15 (11.9)65 to 74 13 (31.0) 39 (31.0)75 to 84 18 (42.9) 54 (42.9)85 and older 6 (14.3) 18 (14.3)

SexMale 26 (61.9) 78 (61.9)Female 16 (38.1) 48 (38.1)

RaceWhite 36 (85.7) 115 (91.3)Nonwhite 6 (14.3) 11 (8.7)

Annual Income0 to $25,000 30 (71.4) 83 (65.9)$25,001 or higher 12 (28.6) 43 (34.1)

EducationHigh school graduate or less 29 (69.0) 95 (75.4)More than high school 13 (31.0) 31 (24.6)

Marital StatusNot married 25 (59.5) 54 (42.9)Married 17 (40.5) 72 (57.1)

Census Bureau Regions†

Northeast 3 (7.1) 21 (16.7)Midwest 10 (23.8) 28 (22.2)South 20 (47.6) 57 (45.2)West South Central 8 (19.0) 20 (15.9)Puerto Rico 1 (2.4) 0 (0.0)

Self-Reported HealthExcellent/Very good/Good 23 (54.8) 82 (65.1)Fair/Poor 18 (42.9) 42 (33.3)Data missing/Unknown 1 (2.4) 2 (1.6)

Number of Comorbid ConditionsNone to three 20 (47.6) 57 45.2)Four or more 22 (52.4) 66 (52.4)Data missing/Unknown 0 (0.0) 3 (2.4)

Charlson Comorbidity Index Score‡

0 1 (2.4) 3 (2.4)1 to 3 23 (54.8) 59 (46.8)4 or higher 18 (42.9) 62 (49.2)Data missing/Unknown 0 (0.0) 2 (1.6)

* Of these matched control participants in the Medicare Current Beneficiary Survey, 63 participants were followed for less than one year afterundergoing total joint arthroplasty, 35 were followed for one to less than two years and 28 were followed for two to less than three years.

† Source: U.S. Census Bureau.21

‡ Source: Charlson and colleagues.20


35JADA Middle East vol 3 No 2 Mar-Apr 2012JADA 142(12) http://jada.ada.org December 2011 1349

providers “consider” the new guide-lines as a supplement to their clin-ical judgment rather than requirethat they follow the guidelines, thepractical result likely is to beincreased prescribing of antibioticsas clinicians seek to minimizemedicolegal risks. Adding to theuncertainty is the new statement’sfailure to define what is meant by“invasive dental procedures.” Majorconcerns raised in recent editorialresponses to the new guidelinesinclude the lack of collaboration withorganized dentistry in producingthem and an absence of evidence-based support for the changes madeto the joint 2003 ADA/AAOS advi-sory statement.4-6

The importance of dental pro-cedures as an ultimate cause of latePJIs remains unresolved. Researchershave shown transient bacteremias tobe caused by several dental pro-cedures (extractions, periodontalprobing, ultrasonic scaling, brushing),but bacteremias also are caused bydaily activities such as chewing.22-24

Some investigators have proposedthat poor oral health and routinedaily activities may create a greaterrisk of experiencing bacteremias thanmay dental procedures.25,26 Also, themajority of late PJIs are associated with staphy-lococci, including Staphylococcus aureus andStaphylococcus epidermidis, which make up asmall percentage of the oral microbiota.17,27

Prosthetic joint infections have been vari-ously classified as early, delayed and lateaccording to time of onset after surgery.6,28,29

Early infections generally are defined as occur-ring within three months of surgery and arethought to be related to the implantation pro-cedure. Late PJIs purportedly result fromhematogenous seeding from bacterial sourcesthat include the skin, the respiratory and uri-nary tracts, and the mouth.22 Late infectionshave been defined variably as occurring aftersix to 24 months after surgery.15,28-30 Defininglate infections as occurring more than one yearafter surgery in our study, we found only two of20 participants with a late infection underwentan invasive dental procedure in the 90-dayperiod before the PJI occurred, suggesting thatlate PJIs are preceded infrequently by invasivedental procedures.

Limitations. This study has several limita-

tions. The MCBS data set includes records ofdental visits and antibiotic use derived fromself-reports or proxy reports, which are subjectto recall error. Recall bias likely is minimizedbecause the survey conducts periodic partici-pant interviews and collects receipts and claimforms; nonetheless, dental care use and antibi-otic use may be underestimated. Also, theMCBS records antibiotic prescriptions onlyaccording to calendar year, and we could notdetermine the dates when prescriptions werewritten or filled, or whether the participantused the antibiotic. Therefore, we could notascertain directly from the MCBS data partici-pants’ antibiotic use for prosthetic joint prophy-laxis. Overall, 234 of 512 participants (45.7 per-cent) who had undergone an invasive dentalprocedure received an antibiotic appropriate forprophylaxis in the same year. Eleven of the 42case participants who had PJI received a pre-scription for an antibiotic appropriate for pro-phylaxis in the year in which they experiencedtheir PJI, including the four participants whounderwent invasive dental procedures within 90

S T O R YC O V E R

TABLE 4

Hazard ratios for dental procedures and risk for prosthetic joint infection.VARIABLE(S) IN THE ANALYSIS, ACCORDINGTO TYPE OF DENTAL PROCEDURE

HAZARD RATIO (95%CONFIDENCE INTERVAL*)

All Dental ProceduresAny in preceding 90 daysProcedures only 0.50 (0.12-2.18)Procedures and education† 0.57 (0.13-2.51)Procedures and age‡ 0.49 (0.11-2.14)Procedures and comorbidities§ 0.49 (0.11-2.12)

Any in preceding 180 daysProcedures only 0.56 (0.18-1.71)Procedures and education 0.66 (0.21-2.05)Procedures and age 0.55 (0.18-1.69)Procedures and comorbidities 0.54 (0.18-1.66)

Invasive Dental Procedures¶



* Wald interval on the log-hazard ratio scale back-transformed to the hazard ratio scale.† Twelve years or less or more than 12 years.‡ Years, entered as a continuous measure.§ According to score on the Charlson comorbidity index (Charlson and colleagues20) and

entered as a continuous measure. ¶ Teeth cleanings, extractions and endodontic procedures only.


36 JADA Middle East vol 3 No 2 Mar-Apr 20121350 JADA 142(12) http://jada.ada.org December 2011

days of their PJI. The MCBS does not record dentulous status,

and some participants reporting a dental visitmay have been edentulous. Invasive proceduresas we defined them, however, would not havebeen reported for edentulous participants. As anadministrative claims data set, the MCBS alsodoes not provide information regarding specificbacteria isolated from infected prostheses. Wedo not know which, if any, of the 42 PJIs wereassociated with oral bacteria.

We could not reliably estimate prevalenceand incidence rates for PJIs because more thanone-half of the PJI case participants underwentarthroplasty before entering the survey. More-over, those who underwent arthroplasty whilein the survey were followed for variableamounts of time, depending on the timing oftheir joint replacement surgery. Nevertheless,the nationally representative MCBS provides aunique opportunity to analyze longitudinalassociations between total joint arthroplasties,dental procedures and the occurrence of PJIs.

For infrequent events (such as invasivedental procedures performed in the 90 daysbefore a PJI), confidence intervals for the HRsand ORs (Tables 4 and 5) are broad and includeclinically relevant values. Thus, we cannotexclude the possibility that dental visits wereassociated with a slight increase in the risk ofdeveloping PJI. Nonetheless, the estimated HRsand ORs were less than one, suggesting thatthis study’s null findings did not arise from alack of statistical power. (Note, too, that theprospective and case-control analyses were notindependent; some of the same participants

appeared in bothanalyses.)

A further limita-tion of the case-control study is thatthe exposure of par-ticular interest—dental procedures’occurring within aninterval precedingthe joint infection—is defined by meansof the bad outcomethat case partici-pants necessarilyexperienced and con-trol participants didnot. To address thisdifference betweencase and control par-ticipants, we consid-

ered a variety of definitions of exposure, all ofwhich gave qualitatively the same result.

Finally, the MCBS includes Medicare benefi-ciaries who are aged or institutionalized or havedisabilities. Although medical comorbiditieswere fairly frequent in this group, our resultsmay have differed had we studied only peoplewho were more medically compromised or wereliving in institutional settings.

A critical need in assessing the clinical valueof antibiotic prophylaxis to prevent PJIs is thedevelopment of more evidence-based study pro-tocols. The results of placebo-controlled, ran-domized clinical trials would provide moredefinitive guidance regarding which patientsneed prophylaxis. However, investigators con-ducting such studies would face ethical concernsrelated to withholding antibiotic prophylaxisfrom people, an action that may increase thepatient’s risk of experiencing a serious infectionand the logistical challenges of recruiting alarge study population, given the low frequencyof PJIs. Practically, more helpful information forfuture practice guidelines may need to comefrom additional prospective case-control orcohort studies.

CONCLUSIONSIn this retrospective MCBS database analysis,which we conducted across a 10-year period, wefound 42 participants who had PJIs and a lowoverall rate of subsequent PJIs (1.8 percent)among those who had undergone total jointarthroplasty while participating in the survey.We found no significant increase in risk ofdeveloping PJI after dental visits, including

S T O R YC O V E R

TABLE 5

Association between preceding dental visitprocedures and prosthetic joint infection (PJI).DENTALPROCEDURE

PARTICIPANTS, NO. (PERCENTAGE) ODDS RATIO(95% CI)*

PVALUE†

Case Participants (n = 42)

Control Participants(n = 126)

Any DentalProcedure90 days before LRD‡ 5 (11.9) 26 (20.6) 0.52 (0.19-1.45) .26180 days before LRD 8 (19.0) 41 (32.5) 0.49 (0.21-1.15) .12

Invasive DentalProcedure§

90 days before LRD 4 (9.5) 20 (15.9) 0.56 (0.18-1.74) .45180 days before LRD 6 (14.3) 30 (23.8) 0.53 (0.20-1.39) .28

* This confidence interval (CI) does not account for the clustering of a case participant with his or herthree matched control participants.

† From Mantel-Haenszel test.‡ LRD: Last relevant date. For participants with PJI, the LRD is the date of infection; for control

participants, the LRD is the date of death or Dec. 31 of the last year in which they took part in the survey.

§ Teeth cleanings, extractions and endodontic procedures only.


37JADA Middle East vol 3 No 2 Mar-Apr 2012JADA 142(12) http://jada.ada.org December 2011 1351

those involving more invasive procedures. Thestudy results support the contention that the2009 AAOS Information Statement on antibioticprophylaxis for patients with prosthetic jointsshould be reconsidered for patients in that pop-ulation who are receiving oral health care.4-6

�

Disclosure. None of the authors reported any disclosures.

The research described in this article was supported in part by theErwin Schaffer Chair in Periodontal Research (held by Dr. Bryan S.Michalowicz).

The authors thank Marc F. Swiontkowski, MD, professor,Orthopaedic Surgery, University of Minnesota, Minneapolis, for hiscontributions.

1. American Academy of Orthopaedic Surgeons. Information state-ment: antibiotic prophylaxis for bacteremia in patients with jointreplacements. “www.aaos.org/about/papers/advistmt/1033.asp”.Accessed Sept. 27, 2011.

2. American Dental Association, American Academy of OrthopaedicSurgeons. Antibiotic prophylaxis for dental patients with total jointreplacements. JADA 1997;128(7):1004-1008.

3. American Dental Association, American Academy of OrthopaedicSurgeons. Antibiotic prophylaxis for dental patients with total jointreplacements. JADA 2003;134(7):895-899.

4. Marek CL, Ernst EJ. The new American Academy of OrthopaedicSurgeons’ recommendations regarding antibiotic prophylaxis: where’sthe evidence? Spec Care Dentist 2009;29(6):229-231.

5. Napenas JJ, Lockhart PB, Epstein JB. Comment on the 2009American Academy of Orthopaedic Surgeons’ information statementon antibiotic prophylaxis for bacteremia in patients with jointreplacements. J Can Dent Assoc 2009;75(6):447-449.

6. Little JW, Jacobson JJ, Lockhart PB; American Academy of OralMedicine. The dental treatment of patients with joint replacements:a position paper from the American Academy of Oral Medicine. JADA2010;141(6):667-671.

7. Buie VC, Owings MF, DeFrances CJ, Golosinskiy A. NationalHospital Discharge Survey: 2006 summary. National Center forHealth Statistics. Vital Health Stat 2010;13(168).

8. Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of pri-mary and revision hip and knee arthroplasty in the United Statesfrom 2005 to 2030. J Bone Joint Surg Am 2007;89(5):780-785.

9. Bozic KJ, Katz P, Cisternas M, Ono L, Ries MD, Showstack J.Hospital resource utilization for primary and revision total hiparthroplasty. J Bone Joint Surg Am 2005;87(3):570-576.

10. Curry S, Phillips H. Joint arthroplasty, dental treatment, andantibiotics: a review. J Arthroplasty 2002;17(1):111-113.

11. Segreti J. Is antibiotic prophylaxis necessary for preventingprosthetic device infection? Infect Dis Clin North Am 1999;13(4):871-817, vii.

12. Rubin R, Salvati EA, Lewis R. Infected total hip replacementafter dental procedures. Oral Surg Oral Med Oral Pathol 1976;41(1):18-23.

13. Sullivan PM, Johnston RC, Kelley SS. Late infection after totalhip replacement, caused by an oral organism after dental manipula-tion: a case report. J Bone Joint Surg Am 1990;72(1):121-123.

14. Lockhart PB, Loven B, Brennan MT, Fox PC. The evidence basefor the efficacy of antibiotic prophylaxis in dental practice. JADA2007;138(4):458-474.

15. Uckay I, Pittet D, Bernard L, Lew D, Perrier A, Peter R. Antibi-otic prophylaxis before invasive dental procedures in patients witharthroplasties of the hip and knee. J Bone Joint Surg Br 2008;90(7):833-838.

16. Centers for Medicaid and Medicare Services. Medicare CurrentBeneficiary Survey (MCBS): overview. “www.cms.gov/mcbs/”.Accessed Sept. 27, 2011.

17. Berbari EF, Osmon DR, Carr A, et al. Dental procedures as riskfactors for prosthetic hip or knee infection: a hospital-based prospec-tive case-control study. Clin Infect Dis 2010;50(1):8-16.

18. National Center for Health Statistics, Centers for Medicare andMedicaid Services. International Classification of Diseases, 9th Revi-sion, Clinical Modification. Baltimore: Centers for Medicare andMedicaid Services; 2010.

19. Wilson W, Taubert KA, Gewitz M, et al. Prevention of infectiveendocarditis: guidelines from the American Heart Association—aguideline from the American Heart Association Rheumatic Fever,Endocarditis and Kawasaki Disease Committee, Council on Cardio-vascular Disease in the Young, and the Council on Clinical Cardi-ology, Council on Cardiovascular Surgery and Anesthesia, and theQuality of Care and Outcomes Research Interdisciplinary WorkingGroup. JADA 2007;138(6):739-745, 747-760.

20. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A newmethod of classifying prognostic comorbidity in longitudinal studies:development and validation. J Chronic Dis 1987;40(5):373-383.

21. U.S. Census Bureau. Census regions and divisions of theUnited States. “www.census.gov/geo/www/us_regdiv.pdf”. AccessedOct. 30, 2011.

22. Jacobson JJ, Millard HD, Plezia R, Blankenship JR. Dentaltreatment and late prosthetic joint infections. Oral Surg Oral MedOral Pathol 1986;61(4):413-417.

23. Kinane DF, Riggio MP, Walker KF, MacKenzie D, Shearer B.Bacteraemia following periodontal procedures. J Clin Periodontol2005;32(7):708-713.

24. Lockhart PB, Brennan MT, Sasser HC, Fox PC, Paster BJ,Bahrani-Mougeot FK. Bacteremia associated with toothbrushing anddental extraction (published online ahead of print June 9, 2008). Cir-culation 2008;117(24):3118-3125. doi:10.1161/CIRCULATIONAHA.107.758524.

25. Oswald TF, Gould FK. Dental treatment and prosthetic joints:antibiotics are not the answer! J Bone Joint Surg Br 2008;90(7):825-826.

26. Lockhart PB, Brennan MT, Thornhill M, et al. Poor oralhygiene as a risk factor for infective endocarditis-related bacteremia.JADA 2009;140(10):1238-1244.

27. Forner L, Larsen T, Kilian M, Holmstrup P. Incidence of bac-teremia after chewing, tooth brushing and scaling in individuals withperiodontal inflammation. J Clin Periodontol 2006;33(6):401-407.

28. LaPorte DM, Waldman BJ, Mont MA, Hungerford DS. Infec-tions associated with dental procedures in total hip arthroplasty. J Bone Joint Surg Br 1999;81(1):56-59.

29. Zimmerli W, Trampuz A, Ochsner PE. Prosthetic-joint infec-tions. N Engl J Med 2004;351(16):1645-1654.

30. Waldman BJ, Mont MA, Hungerford DS. Total knee arthro-plasty infections associated with dental procedures. Clin OrthopRelat Res 1997;(343):164-172.

S T O R YC O V E R



days of their PJI. The MCBS does not record dentulous status,

and some participants reporting a dental visitmay have been edentulous. Invasive proceduresas we defined them, however, would not havebeen reported for edentulous participants. As anadministrative claims data set, the MCBS alsodoes not provide information regarding specificbacteria isolated from infected prostheses. Wedo not know which, if any, of the 42 PJIs wereassociated with oral bacteria.

We could not reliably estimate prevalenceand incidence rates for PJIs because more thanone-half of the PJI case participants underwentarthroplasty before entering the survey. More-over, those who underwent arthroplasty whilein the survey were followed for variableamounts of time, depending on the timing oftheir joint replacement surgery. Nevertheless,the nationally representative MCBS provides aunique opportunity to analyze longitudinalassociations between total joint arthroplasties,dental procedures and the occurrence of PJIs.

For infrequent events (such as invasivedental procedures performed in the 90 daysbefore a PJI), confidence intervals for the HRsand ORs (Tables 4 and 5) are broad and includeclinically relevant values. Thus, we cannotexclude the possibility that dental visits wereassociated with a slight increase in the risk ofdeveloping PJI. Nonetheless, the estimated HRsand ORs were less than one, suggesting thatthis study’s null findings did not arise from alack of statistical power. (Note, too, that theprospective and case-control analyses were notindependent; some of the same participants

appeared in bothanalyses.)

A further limita-tion of the case-control study is thatthe exposure of par-ticular interest—dental procedures’occurring within aninterval precedingthe joint infection—is defined by meansof the bad outcomethat case partici-pants necessarilyexperienced and con-trol participants didnot. To address thisdifference betweencase and control par-ticipants, we consid-

ered a variety of definitions of exposure, all ofwhich gave qualitatively the same result.

Finally, the MCBS includes Medicare benefi-ciaries who are aged or institutionalized or havedisabilities. Although medical comorbiditieswere fairly frequent in this group, our resultsmay have differed had we studied only peoplewho were more medically compromised or wereliving in institutional settings.

A critical need in assessing the clinical valueof antibiotic prophylaxis to prevent PJIs is thedevelopment of more evidence-based study pro-tocols. The results of placebo-controlled, ran-domized clinical trials would provide moredefinitive guidance regarding which patientsneed prophylaxis. However, investigators con-ducting such studies would face ethical concernsrelated to withholding antibiotic prophylaxisfrom people, an action that may increase thepatient’s risk of experiencing a serious infectionand the logistical challenges of recruiting alarge study population, given the low frequencyof PJIs. Practically, more helpful information forfuture practice guidelines may need to comefrom additional prospective case-control orcohort studies.

CONCLUSIONSIn this retrospective MCBS database analysis,which we conducted across a 10-year period, wefound 42 participants who had PJIs and a lowoverall rate of subsequent PJIs (1.8 percent)among those who had undergone total jointarthroplasty while participating in the survey.We found no significant increase in risk ofdeveloping PJI after dental visits, including

S T O R YC O V E R

TABLE 5

Association between preceding dental visitprocedures and prosthetic joint infection (PJI).DENTALPROCEDURE

PARTICIPANTS, NO. (PERCENTAGE) ODDS RATIO(95% CI)*

PVALUE†

Case Participants (n = 42)

Control Participants(n = 126)

Any DentalProcedure90 days before LRD‡ 5 (11.9) 26 (20.6) 0.52 (0.19-1.45) .26180 days before LRD 8 (19.0) 41 (32.5) 0.49 (0.21-1.15) .12

Invasive DentalProcedure§

90 days before LRD 4 (9.5) 20 (15.9) 0.56 (0.18-1.74) .45180 days before LRD 6 (14.3) 30 (23.8) 0.53 (0.20-1.39) .28

* This confidence interval (CI) does not account for the clustering of a case participant with his or herthree matched control participants.

† From Mantel-Haenszel test.‡ LRD: Last relevant date. For participants with PJI, the LRD is the date of infection; for control

participants, the LRD is the date of death or Dec. 31 of the last year in which they took part in the survey.

§ Teeth cleanings, extractions and endodontic procedures only.


dental procedures and subsequent prosthetic joint infections …€¦ · an endodontist, who also...

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