Archives of Oral Biology 64 (2016) 39–50

Review

Systemic antibiotics and the risk of superinfection in peri-implantitis

Fernando Verdugoa,*, Theresia Laksmanab, Agurne Uribarric

aDepartment of Periodontics, VA Hospital, Greater Los Angeles Healthcare System, USAbAdvanced Periodontology, University of Southern California School of Dentistry, Los Angeles, CA, USAcDepartment of Oral Medicine, School of Medicine and Odontology, University of Basque Country, Leioa, Spain

A R T I C L E I N F O

Article history:Received 8 July 2015Received in revised form 29 November 2015Accepted 23 December 2015

Keywords:Peri-implantitisSuperinfectionOpportunistic infectionEnterobacteriaceaeAnti-bacterial agentsCandidiasisherpesviridae

A B S T R A C T

Peri-implantitis has emerged in the last few years as a complication difficult to resolve. Theetiopathogenesis consensus is mainly attributed to bacteria. Following the preferred reporting items forsystematic reviews and meta-analysis (PRISMA) guidelines, a PubMed/Medline literature search wasperformed using the US National Library of Medicine database up to 2015 to analyze available scientificdata on the rationale and risk of superinfection associated to systemic antimicrobials in human peri-implant disease. A hand search was also conducted on relevant medical and microbiology journals. Themethodological index for non-randomized studies (MINORS) was independently assessed for quality onthe selected papers. Proposed combined therapies use broad-spectrum antibiotics to halt the diseaseprogression. A major associated risk, particularly when prescribed empirically without microbiologicalfollow-up, is the undetected development of superinfections and overgrowth of opportunistic pathogensdifficult to eradicate. Peri-implant superinfections with opportunistic bacteria, yeast and viruses, areplausible risks associated to the use of systemic antibiotics in immunocompetent individuals. Lack ofmicrobiological follow-up and antibiotic susceptibility testing may lead to ongoing microbial challengesthat exacerbate the disease progression. The increased proliferation of antimicrobial resistance, modernimplant surface topography and indiscriminative empiric antibiotic regimens may promote theescalation of peri-implant disease in years to come. A personalized 3-month supportive therapy may helpprevent risks by sustaining a normal ecological balance, decreasing specific pathogen proportions andmaintaining ideal plaque control.

ã 2015 Elsevier Ltd. All rights reserved.

Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402. Methodology and quality assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413. Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

3.1. Antimicrobial resistance and the risk of thriving superinfecting pathogens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413.2. Ability/inability to disrupt the peri-implant submucosal biofilm and maintain health . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423.3. Systemic antibiotics in the treatment of peri-implantitis (Tables 1 and 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423.4. Surgical treatment of peri-implantitis without systemic antibiotics (Table 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453.5. Summary of systematic review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

4. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Conflict of interest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Author contribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Funding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Competing interest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Ethical approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Contents lists available at ScienceDirect

Archives of Oral Biology

journa l homepage: www.e lsev ier .com/ locate /aob

* Corresponding author at: 2028 North Lake Avenue, Altadena, California 91001,USA. Fax: +1 626 797 0523.

E-mail address: fverdugo@perio.org (F. Verdugo).

http://dx.doi.org/10.1016/j.archoralbio.2015.12.0070003-9969/ã 2015 Elsevier Ltd. All rights reserved.

40 F. Verdugo et al. / Archives of Oral Biology 64 (2016) 39–50

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

1. Introduction

Osseointegrated dental implants have become a predictabletreatment option in providing function in partial or totaledentulism, delivering high success rate outcomes long term(Albrektsson, Zarb, Worthington, & Ericsson, 1986). However, withan estimated twelve million implants placed annually worldwide,peri-implant disease has increasingly become a complication,often, difficult to resolve (Persson, Samuelsson, Lindahl, & Renvert,2010a; Esposito, Grusovin, & Worthington, 2012; Albrektsson,Dahlin, Jemt, Sennerby, Turri, & Wennerberg, 2014).

Controversy exists regarding disease initiation, namely wheth-er specific pathogenic microbiota are indeed the true initiators ofbone loss around implants or if they are secondary to a dis-balanced foreign body reaction coupled with background factorssuch as poorly fabricated implants placed by unqualified clinicians(Albrektsson et al., 2014; Qian, Wennerberg, & Albrektsson, 2012).Nevertheless, the European Federation of Periodontology consen-sus proposed that bacteria are the sole cause of peri-implantdisease with associated risk factors such as poor oral hygiene,history of periodontitis, diabetes or smoking (Lindhe, Meyle, GroupD of European Workshop on Periodontology).

Regardless of the initiating etiological factors, there isagreement that the disease process is exacerbated and maintainedby specific microbial infection with bacteria and possibly viruses(Rams, Degener, & van Winkelhoff, 2014; Verdugo et al., 2015a;Verdugo, Castillo, Castillo, & Uribarri, 2015; Heitz-Mayfield, Salvi,Mombelli, Faddy, & Lang, 2012). Specific microbial contaminationhas been shown to impair osteogenesis, and increased bone loss

Fig. 1. Search strategy flowchart summary of syst

has been associated with the presence of key anaerobic species andsalivary Epstein-Barr virus (EBV) (Verdugo et al., 2012).

Therefore, some research groups have proposed combined,surgical and non-surgical, therapies where systemic antibiotics areadministered to empirically target specific putative bacteria (Ramset al., 2014a; Heitz-Mayfield et al., 2012). The risks associated withempiric therapy are not only potential antibiotic resistance but,most importantly, the development of superinfections difficult toeradicate (Rams, Degener, & van Winkelhoff, 2014a; Rams,Degener, & van Winkelhoff, 2014b). Peri-implant opportunisticinfections may be a significant risk associated with empiric broad-spectrum antibiotic regimens in immunocompetent individuals.The negative impact of antimicrobial agents on the normalprotective microflora has been documented for decades (Sullivan,Edlund, & Nord, 2001). The human oropharyngeal, intestinal andvaginal ecological balance can be altered after antibiotic exposure,favoring the overgrowth of opportunistic pathogens (Sullivan et al.,2001).

Lack of follow-up and antibiotic susceptibility testing may leavespecific ongoing microbial challenges difficult to eliminate,allowing disease progression to perpetuate. So far, superinfectionshave not been documented with the use of broad-spectrumantibiotics in peri-implant disease. However, there have beenreports of rapidly progressive, non-responsive to treatment peri-implantitis, in cases where broad-spectrum antibiotic therapy wasused (Emrani, Chee, & Slots, 2009; van Winkelhoff & Wolf, 2000).Indeed, the increase of subgingival superinfecting agents, such as,Enterobacter,Candida, or Staphylococcus species, can flourish afterthe administration of systemic antimicrobials (Helovuo, Hakkar-ainen, & Paunio, 1993).

ematic review following PRISMA guidelines.

F. Verdugo et al. / Archives of Oral Biology 64 (2016) 39–50 41

The present study was conducted to review available scientificdata on the rationale and to qualitatively assess the potential risk ofsuperinfection after systemic antimicrobials in human peri-implant disease.

2. Methodology and quality assessment

The focused PICO question for the present review is: is there arisk of developing a superinfection in peri-implantitis lesions afterthe use of systemic antimicrobials?

The present systematic review work was conducted followingthe guidelines (www.prisma-statement.org) of the preferredreporting items for systematic reviews and meta-analysis(PRISMA). A literature search was performed on Medline usingthe PubMed database of the US National Library of Medicine,Scielo, Lilacs, OVID and Google Scholar up to 2015. The followingkey words were used: (periimplantitis OR peri-implantitis) AND(treatment OR therapy OR therapeutics) AND (anti-bacterial agentOR antibiotics OR anti-infective agent OR antimicrobial). Thesearch used the MeSH browser and was limited to paperspublished in English; humans; clinical trials; randomized clinicaltrials (RCT); and meta-analysis. The search was further refined byusing the combination of terms: peri-implantitis AND treatmentAND antibiotics AND opportunistic infections AND superinfection.Also; a hand search was performed in the following journals:Clinical Implant Dentistry and Related Research; Clinical OralImplant Research; Clinical Oral Investigations; Journal of ClinicalPeriodontology; Journal of Periodontology; International Journal ofOral and Maxillofacial Implants and Medicina Oral Patologia OralCirugia Bucal. Titles and abstracts were screened for relevance.Papers repeated or with missing data; case reports and animalstudies were excluded. For the purpose of developing scientificdebate and further address the issue on the concept and rational ofantibiotic-associated/induced superinfections, additional scientif-ic articles from the medical literature were selected for evaluation.The methodological index for non-randomized studies (MINORS)was independently assessed for quality on the selected papers(Table 2) by two of the authors.

The quality assurance of the present systematic study wasachieved by conducting the review through independent screeningby two reviewers, resolution of disagreement by consensus,discarding of papers whenever a consensus was not reached,and duplicate data extraction.

3. Results

The initial literature search generated 652 articles of which81 were potentially relevant for analysis (Fig. 1). After screeningtitles and abstracts a total of 19 studies were reviewed. A final full-text evaluation selected 7 clinical studies (Tables 1 and 2) and onereview (Esposito et al., 2012) for analysis based on the aforemen-tioned inclusion criteria. Due to the scarcity of data on theparticular focus question, the heterogeneity of data reported, andlack of microbiological follow-up of most reviewed studies, astatistical meta-analysis is not feasible at this point. Therefore, thepresent systematic review performs a qualitative evaluation of theexisting published scientific data to critically appraise and analyzerelevant information from selected studies to summarize thefindings on a clearly focused area. Furthermore, to enhance thesystematic debate on the concept and rationale of antibiotic-induced superinfections, additional scientific data from themedical literature are selected for evaluation and discussion.

The use of systemic antimicrobials has been indicated indistinct clinical scenarios of severe and aggressive forms of rapidlyprogressive periodontitis in patients presenting with specificmicrobial profiles (Herrera, Alonso, León, Roldán, & Sanz, 2008).

However, there is, in fact, no established protocol for the use ofantibiotic therapy in destructive periodontitis (Haffajee, Socransky,& Gunsolley, 2003). Likewise, a similar lack of protocol exists in thetreatment of peri-implant disease.

3.1. Antimicrobial resistance and the risk of thriving superinfectingpathogens

The reduced vulnerability to anti-infective agents and patho-genic synergism originates from the ability to organize in microbialcommunities or biofilms (Marsh, 2005). If the subgingival biofilmis not sufficiently disrupted, by non-surgical or surgical means, theantimicrobial agent will not be as effective, and thus, thedevelopment of bacterial resistance will be more likely to emerge.

Antibiotic resistance is due to a number of factors, such as, thebiofilm extra-cellular matrix (Mah et al., 2003), the differentbacterial physiological phases within the biofilm (Anderl, Zahller,Roe, & Stewart, 2003), the potential horizontal gene transfer(Roberts, Pratten, Wilson, & Mullany, 1999), quorum sensingcommunication between bacterial cells (Roberts & Mullany, 2006)and their pathogenic ability to invade host cells, such as, epithelialcells and connective tissue (Eick & Pfister, 2004).

Strains of Streptococcus oralis recovered from a subgingivalbiofilm were shown to pass on doxycyline resistance, throughhorizontal gene transfer, to other species, in patients undergoingperiodontal therapy with the antibiotic (Warburton, Palmer,Munson, & Wade, 2007). Similar transfer has been widelydemonstrated between superinfecting bacteria, in particular,Enterococcus faecalis and Staphylococcus aureus, with differentantibiotics (Weigel et al., 2003). Enterobacter species havedeveloped a reputation for their ability to acquire and transfermultidrug resistance to a number of antibiotics such as beta-lactams, tetracyclines, aminoglycosides and even quinolones(Sanders & Sanders, 1997; Choi et al., 2008; Naesens, Ursi, VanSchaeren, & Jeurissen, 2009). Conversely, systemic doxycyclinetherapy in periodontitis patients has yielded a subgingivalovergrowth of a 10-fold increase of superinfecting agents, suchas, enteric rods, yeasts and staphylococci (Rams, Babalola, & Slots,1990).

Certain strains of S. aureus periodontal isolates, one of the mostcommon superinfecting bacteria, have been shown to produce aleukotoxin capable of destroying the human neutrophil first line ofdefense (Iwase, Slots, Berthold, & Taichman, 1990). Their potentendotoxins coupled with their ability to invade human cells andconnective tissue could exacerbate oral tissue breakdown arounddental implants that lack a well-vascularized periodontal ligamentspace (Emrani et al., 2009; van Winkelhoff & Wolf, 2000; Eick &Pfister, 2004; Sanders & Sanders, 1997; Iwase et al., 1990; Martin,Wächtler, Schaller, Wilson, & Hube, 2011).

Absent from healthy implants sites, isolates of Candida spp. andenteric rods have been reported in up to 55% of peri-implantitislesions (Leonhardt, Renvert, & Dahlén, 1999). The pathogenicassets of Candida albicans can make this microorganism difficult toeradicate due to its capacity to invade host cells, form hyphae,secrete proteinases, and interact with commensal streptococci tosynergistically promote its virulence (Martin et al., 2011; Xu et al.,2014). Long term C. albicans infection may induce persistent andchronic tissue destruction through pro-inflammatory cytokine up-regulation (Martin et al., 2011; Dongari-Bagtzoglou, Kashleva, &Villar, 2004). The degree of cytolytic activity seems to triggerinterleukin IL-1alpha from C. albicans-infected oral epithelial cellsto increase cytokine secretion from uninfected epithelial cells(Dongari-Bagtzoglou et al., 2004).

Another superinfecting agent that can exacerbate tissuebreakdown and further alter the ecological balance of peri-implantdiseased tissues is Epstein-Barr virus (EBV). Recent human

42 F. Verdugo et al. / Archives of Oral Biology 64 (2016) 39–50

research has shown that peri-implantitis lesions were 14 timesmore likely to be infected with the virus than healthy sites, and3 times more likely than the patient's saliva within the sameindividual giving EBV a 90% positive predictive value for peri-implantitis infection (Verdugo, Castillo, Castillo, et al., 2015).Notably, research has shown that periodontitis lesions canaggravate, if infected by EBV, correlating disease severity withits presence (Vincent-Bugnas et al., 2013; Kato, Imai, Ochiai, &Ogata, 2013). EBV and Porphyromonas gingivalis have been shownto act synergistically to potentiate disease progression and tissuedestruction (Kato et al., 2013). The likelihood of acquiringperiodontitis was 4.7 times higher when the two pathogens weretogether in deep periodontal pockets of individuals with chronicperiodontitis versus over two times when the pathogens werefound alone (Kato et al., 2013). A different study showed thatpatients with clinical symptoms could be over 3 times more likelyto be infected with EBV than asymptomatic ones, and saliva EBVpositive individuals were 7 and 3.5 times more likely to yieldgranulation tissue contamination with Tannerella forsythia andTreponema denticola, respectively (Verdugo et al., 2015b). Differentvulnerable populations might be at greater risk of herpesvirus-bacterial active infection or reactivation and, thus, prevalence ratesmay substantially fluctuate (Slots, 2010).

Gingival epithelial cells, from the junctional epithelium andsulcus, are commonly infected with EBV and may serve asimportant oral reservoirs of latent EBV-infected cells (Vincent-Bugnas et al., 2013). EBV has the ability to infect and establish alatent phase with a variety of cells, such as epithelial andendothelial cells, lymphocytes and neutrophils. However, whenfacing the innate immune response, the virus seems to be moreprone to induce cellular apoptosis on over 75% of the surroundingneutrophils in less than 24 h post-EBV infection (Larochelle,Flamand, Gourde, Beauchamp, & Gosselin, 1998). Consequently,after down-regulating and disrupting the local immune response,an overgrowth of periodontopathic bacteria and yeast couldpotentiate peri-implant tissue breakdown.

3.2. Ability/inability to disrupt the peri-implant submucosal biofilmand maintain health

In an attempt to eliminate pathogenic biofilms around peri-implantitis lesions and to decontaminate the implant surfaceallowing for the re-establishment of an inflammation-freeenvironment (Mellado-Valero, Buitrago-Vera, Solá-Ruiz, & Fer-rer-García, 2013), open flap surgical access has gained momentum(Esposito et al., 2012; Lindhe et al., 2008; Heitz-Mayfield et al.,2012).

Non-surgical mechanical therapy, using curettes or ultrasonicdevices in peri-implantitis lesions, has shown to be ineffective inreducing bacterial counts at six months (Persson, Samuelsson,Lindahl, & Renvert, 2010b) and would possibly have parallel effectsin virion reduction due to EBV’s capacity to infect epithelial andendothelial cells from the implant biologic width. Nonetheless,when a surgical open flap approach was performed, mechanicaltherapy alone was able to significantly reduce bacterial counts at3 months (Máximo et al., 2009).

Modern implants rough topography would explain the difficul-ty of achieving optimal surface degranulation and decontamina-tion with or without surgical access. Unfortunately, currentavailable scientific literature lacks long-term microbiologicalfollow-up studies showing successful maintenance of peri-implantitis patients. Lack of follow-up and antibiotic susceptibilitytesting may leave specific ongoing microbial challenges difficult toeradicate, allowing peri-implantitis lesions to progress. Multipledocumented clinical research have reported rapidly progressive,non-responsive to treatment peri-implantitis where broad-

spectrum antibiotics were used (Rams et al., 2014a; Emraniet al., 2009; van Winkelhoff & Wolf, 2000; Leonhardt et al., 1999).

Implant surface characteristics seem to influence the progres-sion of peri-implantitis lesions and bone loss due to the difficulty ofachieving optimal surface decontamination. Today's modernimplant surface area roughness values average approximately2.0–2.5 mm pit. Superinfecting bacteria of the Enterobacteriaceaefamily, including, E. coli, Enterobacter aerogenes, Enterobactercloacae, Salmonella enteritidis, Klebsiella pneumonia or Shigelladysenteriae, among others, are Gram negative facultative anaerobicrods, glucose fermenters and nitrate reducers, usually associatedwith intestinal, urinary and respiratory tract infections, but can befound in almost all natural habitats including the oral cavity. Theyhave on average diameters of 0.5-1 mm and lengths of approxi-mately 2 mm and have been found infecting implant and prostheticdevices (Sanders & Sanders, 1997; Choi et al., 2008; Naesens et al.,2009; Rams et al., 1990). These microorganisms are posed toflourish in years to come due to their ability to develop multidrugresistance to a number of broad-spectrum antibiotics such as beta-lactams, tetracyclines, aminoglycosides or even quinolones. Risksthat can lead to the development of these superinfecting agentsinclude, among other factors, prolonged hospital stay, immuno-suppression, nail-biting, the use of contaminated toothbrushes orthe presence of a foreign device such as an implant (Sanders &Sanders, 1997; Rams et al., 1990).

When left untreated, disease progression may be morepronounced on moderately rough surface area implants withSa-values of 2.29 mm than on polished ones with Sa-values of0.35 mm (Berglundh, Gotfredsen, Zitzmann, Lang, & Lindhe, 2007).The amount of bone loss after a period of plaque accumulation wassignificantly larger at implants with anodized surfaces (TiUnite1)than at implants with turned surfaces (Albouy, Abrahamsson, &Berglundh, 2012). The available scientific data suggest that theability to eliminate the pathogenic biofilm from peri-implantitislesions will be more compromised and difficult to achieve on roughimplant surfaces (Charalampakis, Ramberg, Dahlén, Berglundh, &Abrahamsson, 2014). Scanning electron microscopy and microbio-logical analysis showed that the combination of mechanical andchemical cleansing failed to completely remove the bacterialbiofilm from easily accessible titanium discs worn during 4 days byhealthy individuals (Charalampakis et al., 2014).

At present, there is still no study proposing an effective, reliablemethodology for treating peri-implant disease. Treatment inter-ventions for peri-implantitis with follow-ups longer than one yearhave suggested disease recurrence in up to 100% of the treatedindividuals (Esposito et al., 2012). Due to the chronic nature of thedisease and the difficulty to eradicate causative pathogens, re-treatment seems likely (Esposito et al., 2012).

As a result, maintaining healthy peri-implant tissues long-termmight be an uncertain mission. Moreover, periodontal mainte-nance patients tend to harbor significantly higher levels of the redcomplex bacteria and long-term control of aggressive periodonto-pathic bacteria seems a difficult task to attain (Teles, Patel,Socransky, & Haffajee, 2008; Buchmann, Müller, Heinecke, & Lange,2000).

A key aspect in both periodontitis and peri-implantitis patientsis establishing a rigorous and personalized maintenance protocolassessing individual microbial profiles regularly to be able tomonitor potential clinical changes and reduce risks.

3.3. Systemic antibiotics in the treatment of peri-implantitis(Tables 1 and 2)

Lack of clear guidelines from periodontitis studies and scarcityof scientific data from peri-implantitis research, on the use ofsystemic antibiotics, can translate into unsafe science-based

F. Verdugo et al. / Archives of Oral Biology 64 (2016) 39–50 43

clinical decisions. Few peri-implantitis studies have evaluatedtheir use in humans and only one case series study has reportedclinical and microbiological results up to five years (Leonhardt,Dahlén, & Renvert, 2003). A recent study showed that theadditional use of systemic antibiotics did not have a significantclinical impact on the treatment of peri-implant mucositis at6 months as compared to non-surgical debridement alone(Hallström, Persson, Lindgren, Olofsson, & Renvert, 2012). Argu-ably, the selection of the antibiotic, dosage and duration could havepossibly yielded different outcomes. Conversely, a trend forimproved clinical and microbiological results could be observedin individuals with severe periodontitis taking metronidazole andamoxicillin for 14 days instead of the usual 7-day protocol (Feres,

Table 1Clinical peri-implantitis studies using systemic antimicrobials.

Study & follow-up Protocol Outcome

Human 1-yearwithmicrobiologicalfollow-upN = 9 patients

Non-surgical mechanical therapy + 0.5% CHXirrigation + 1 g/day/10days systemicornidazole + home pocket 0.2% CHX irrigation

Immediateimprovemvs. the 42%G+ anaero1 year

Human 5-yearwithmicrobiologicalfollow-upN = 9 patients

Surgical debridement: decontamination with10%hydrogen peroxide + saline solution. Postop 0.2% CHXrinse 2 weeks + individualized systemic antibioticsbased on susceptibility test (amoxicillin + metro;metronidazole; tetracycline;clindamycin;ciprofloxacin) single daily dose for 2 or 4 weeks

Clinical, mtreatment

Periodonto9 treated pnecessary;unchanged

Human 1-yearNomicrobiologicaltestingN = 24 patients

Surgical access + titanium/carbon fibercurettes + irrigation with sterile saline + gauze soakedin sterile saline. Systemic antibiotics 7daysamoxicillin + metronidazole + 0.20% CHX rinse4 weeks

Clinical an3 months fimplants)

at twelve

complete rbone loss

side effect

Human 2-yearNomicrobiologicaltestingN = 31 patients

Resective surgical therapy + osseous re-contouring,implant surface debridement and decontaminationwith CHX irrigation and apically re-positioned flaps;300 mg clindamycin TID 1week, +0.12% CHX rinsetwice/day/2 weeks

From 31 p(77%) withImplants w�5 mm at

implant diHuman 3-yearMicrobiologicaltesting only atbaselineN = 25 patients

Surgical access + autogenous bone grafting & systemicantibiotics administered following baseline microbiolsusceptibility test: 1 week; sites treated with nomembranes or non-resorbable and resorbablemembranesDefects irrigated with 0.2% CHX & citric acid (pH 1)applied for one minute onto the implant surface andthen rinsed with H2O2 and 0.9% saline

Dehiscencstrongly astime;None of thmembrane

Human 1–5 yearNomicrobiologicaltestingN = 36 patientsat 1 yearN = 25 at 5 years

Surgical access + bone substitute (algae derived) usedto fill peri-implant defects with & without resorbablemembranes. Implant decontaminated with 3% H2O2

and rinsed with saline; systemic antibiotics for10 days starting day before surgery: amoxicillin(375 mg TID) + metronidazole (400 mg BID) orclindamycin (300 mg BID) Post-op rinsing 0.1% CHXfor 5 weeks

60% of stuat 1 year iFrequent mimplants aAt 5y follosubstitute

index of 31substitute

RadiograpNo change25). 3-mon5 years.

CHX: chlorhexidine; BOP: bleeding on probing; TID: three times/day; BID: two times/d

Figueiredo, Soares, & Faveri, 2015). Nonetheless, these data needsubstantiation .

Extensive surgical and individualized systemic antimicrobialtherapy has been shown to be insufficient in maintainingpathogen-free peri-implant tissues over a five-year period(Leonhardt et al., 2003). In one study, implants were decontami-nated using 10% hydrogen peroxide followed by sterile salineirrigation, and patients rinsed with 0.2% chlorhexidine twice/dayfor two weeks after surgery. Periodontopathic bacteria were stillpresent in 8 out of the 9 treated patients or 53% of the affected sites(Leonhardt et al., 2003). Microbiological parameters did notimprove by increasing the antibiotic regime to 4 weeks, re-treatment was necessary, and 27% of the study implants were lost

Implant system Author/Year

anaerobic load reduction & clinicalent. At 9 months G-anaerobic rods % up 36%

at pretreatment;bic rods increased from 8.42% to 15.6% at

Titanium hollowcylinder(Straumann)

Mombelli & Lang(1992)

icrobiological and radiographic evaluation:success in 58% of implants treatedpathic bacteria still present in 8 out of theatients (53% of sites); Re-treatment

27% of the study implants lost; the rest/gain or continue to lose bone. No control

BrånemarkSystem (NobelBiocare)

Leonhardt et al.(2003)

d radiological parameters improved afteror up to 12 months; 88% of patients (92% ofwith stable crestal bone levels or bone gainmonths but only 47% of the implants hadesolution of bleeding on probing; ongoingat 12 months in a sub-group of 3 patients;s mostly gastrointestinal in 25%

Brånemarkturned = 5StraumannTPS = 3AstraTiOblast = 2AnodizedTiUnite NobelBiocare = 9StraumannSLA = 11Acid-etchedEntegra/Sybron = 1Plasma-sprayedFrialit-2,Dentsply = 2HA coating,Calcitek = 3

Heitz-Mayfieldet al. (2012)

atients, only 48% had no disease signs; 24 no pockets �6 mm and BOP/suppurationith greater severe bone loss and pocketsbaseline more likely to present peri-sease at follow-up

Brånemark = 122Straumann = 40Astra = 6

Serino & Turri(2011)

e, fistula formation & osseous sequestrumsociated with use of membranes 60% of

e autogenous-only treated sites (without) developed such complications

IMZ & M2,Friadent

Khoury &Buchmann(2001)

dy patients were smokers; bleeding foundn 22–25% of treated implants both groups.embrane exposure at 2 weeks in 43.8% ofnd at 7 weeks (34.4%)w-up, sites treated with bone+ membrane showed increased plaque.5% & bone loss vs. sites treated with boneonlyhic defect fill averaged 1.1–1.3 mm

or loss of bone in 40% of study patients (10/th supportive therapy on all patients for

Brånemarkturned

Roos-Jansåkeret al., (2007);Roos-Jansåkeret al., (2014)

ay; TPS: titanium plasma sprayed; SLA: sand-blasted, large-grit, acid-etched.

Table 2Scores of quality assessment for prospective studies: 12-point MINORS scale.

Study Mombelli & Lang(1992)

Leonhardt et al.(2003)

Heitz-Mayfield et al.(2012)

Serino & Turri(2011)

Khoury & Buchmann(2001)

Roos-Jansåker et al., (2007,2014)

Clear stated aim 2 2 2 2 2 2Inclusion of consecutive patients 2 2 2 2 2 2Prospective collection of data 2 2 2 2 2 2Endpoints appropriate to the aimof study

2 2 2 2 2 2

Unbiased assessment of studyendpoint

2 2 2 2 2 2

Follow-up period appropriateaim

2 2 2 2 2 2

Losses to follow-up less than 5% 2 2 2 1 2 2Prospective calculation of thestudy size

0 0 0 0 0 0

Adequate control group 0 0 0 0 1 0Contemporary groups 2 2 2 2 2 2Baseline equivalence of groups 0 0 0 0 0 2Adequate statistical analyses 1 0 2 2 2 2Total score (out of 24) 17 16 18 17 19 20Study quality Good Good Good Good Good Good

Score 0 (not reported), 1 (reported but inadequate) and 2 (reported and adequate).

44 F. Verdugo et al. / Archives of Oral Biology 64 (2016) 39–50

or continued to lose bone during the 5-year follow-up (Leonhardtet al., 2003). However, microbiological culture monitoring andantibiotic susceptibility testing may have prevented the rise ofimplant superinfections in susceptible individuals harboringenteric rods, including E. coli and E. cloacae, and A. actino-mycetemcomitans at baseline (Leonhardt et al., 2003).

Non-surgical mechanical debridement, local chlorhexidineirrigation and systemic ornidazole (1 g/day/10days) yieldedimmediate improved clinical and microbiological parameters at10 days in a group of nine peri-implantitis patients (Mombelli &Lang, 1992). The authors noted a shift back towards baseline valuesof proportions of Gram-negative anaerobic and facultative rodsthat eventually improved again by the end of the 12-month follow-up. However, at nine months the proportions of these pathogenscombined were up 36% as compared to the pretreatment values of42.5% (Mombelli & Lang, 1992). For Gram-positive anaerobic andfacultative rods, the combined percentages at the end of the12 months were significantly higher than pretreatment levels,15.6% versus 8.4% (Mombelli & Lang, 1992).

Surgical access, for mechanical removal of inflamed granulationtissue and saline implant surface decontamination, coupled withempiric systemic antibiotics (500 mg amoxicillin + 400 mg metro-nidazole 3 times/day/7 days), has been shown to improve clinicalparameters (pocket reduction, bleeding and suppuration) in agroup of 24 peri-implantitis patients (Heitz-Mayfield et al., 2012).

Patients were also instructed to rinse with 0.2% chlorhexidinetwice a day for 4 weeks after surgery and monitored weekly thefirst month and every 3 months thereafter without microbiologicalevaluation throughout the study (Heitz-Mayfield et al., 2012). Theaforementioned non-randomized cohort multi-center studyreported 88% of the patients (92% of implants) having stablecrestal bone levels or bone gain at twelve months but only 47% ofthe implants had complete resolution of bleeding on probing.Three study patients continued to show ongoing bone loss at the12-month follow-up (Heitz-Mayfield et al., 2012). The use ofsystemic amoxicillin and metronidazole was also associated withadverse effects mostly related to gastrointestinal disturbances in25% of the study population (Heitz-Mayfield et al., 2012). Theoropharyngeal as well as intestinal ecological balance can bedisturbed after administration of systemic antibiotics, favoring theovergrowth of opportunistic pathogens (Sullivan et al., 2001;Rashid, Weintraub, & Nord, 2012).

A two year follow-up study reported that resective surgicaltherapy with osseous re-contouring, implant surface debridementand decontamination with chlorhexidine irrigation and apically re-positioned flaps yielded 15 out of the 31 study patients (48%) withno signs of disease and 24 (77%) with no pockets �6 mm and BOP/suppuration (Serino & Turri, 2011). Implants with greater severebone loss and pockets �5 mm at baseline were more likely topresent with peri-implant disease at follow-up. Patients took300 mg of clindamycin three times a day for one week, starting theday before surgery and were instructed to rinse with 0.12%chlorhexidine twice a day for 2 weeks (Serino & Turri, 2011).

A different surgical peri-implantitis approach combiningautogenous bone grafting and systemic antibiotics on 25 patientshas shown controversial results depending on whether mem-branes were used or not for guided bone regeneration (Khoury &Buchmann, 2001). Antibiotics were administered according to amicrobiology susceptibility test performed on each individual atbaseline and were taken for one week starting the day beforesurgery as well as 0.2% chlorhexidine rinse twice/day. Afterdegranulation, peri-implant defects were irrigated with 0.2%chlorhexidine, citric acid (pH 1) applied for one minute onto theimplant surface and then rinsed with hydrogen peroxide and 0.9%saline. Healing complications including dehiscence, fistula forma-tion and osseous sequestrum, were strongly associated with theuse of membranes (resorbable & non-resorbable) 60% of the time.Seventeen out of the 29 membrane treated implants sitesdeveloped early post-operative complications regardless ofsystemic antibiotics administration (Khoury & Buchmann, 2001).In contrast, none of the autogenous-only treated sites (withoutmembrane) developed such complications and probing depthsaveraged 3 mm at the three-year follow-up (Khoury & Buchmann,2001).

The use of an algae derived calcified grafting material has beenused to fill peri-implant defects in a group of 36 patients with andwithout resorbable membranes. Implants were decontaminatedwith 3% hydrogen peroxide and rinsed with saline, and systemicantibiotics were administered for 10 days starting the day beforesurgery, amoxicillin (375 mg TID) + metronidazole (400 mg BID) orclindamycin (300 mg BID). Post-op rinsing with 0.1% chlrohexidinelasted 5 weeks. No microbiological analysis was performed. Themajority of patients (60%) were smokers and the reported bleedingwas found at one year in approximately 22–25% of the treated

F. Verdugo et al. / Archives of Oral Biology 64 (2016) 39–50 45

implants for both groups. Membrane exposure occurred frequentlyat 2 weeks in 43.8% of the treated implants and at 7 weeks (34.4%)(Roos-Jansåker et al., 2007). A 5-year follow-up on the same groupof patients (n = 25) showed that sites treated with the bonesubstitute + membrane had increased bone loss and plaque index(31.5%) versus sites using bone substitute alone. Radiographicdefect fill averaged 1.1–1.3 mm and no change or loss of bone wasobserved in 40% (10/25) of the twenty-five study individuals.Patients followed a personalized 3-month supportive therapy thatallowed maintenance of good plaque control levels (Roos-Jansåkeret al., 2014).

A short 3-month peri-implantitis study evaluating surgicalmechanical therapy without systemic antibiotics has shownsignificant reductions in probing depths, bleeding on probingand bacterial counts (Máximo et al., 2009). Implants were scaledwith Teflon curettes and decontaminated using an abrasive sodiumcarbonate air-power system. Patients were instructed to rinsetwice a day with 0.12% chlorhexidine for one week. Resolution ofinflammation was not successful in 45% of the treated implants andthe main pathogenic species detected at baseline, P. gingivalis, T.denticola, T. forsythia and Parvimonas micra, were still present at theend of the 3 month follow-up (Máximo et al., 2009).

Table 3Clinical peri-implantitis studies without systemic antimicrobials.

Study & follow-up Protocol

Human 1-year Microbiologicaltesting at baseline onlyintra-surgical (pre & postdecontamination)N = 30 patients

Resective surgical therapy + apically re-positionedflaps; debridement & 0.12% CHX vs. salinedecontamination;2 week rinse/2times/day 0.12% CHX + 0.05%CPCwithout alcohol

Human 4-yearNo microbiological testingN = 17 patients

Surgical debridement: surface decontamination Er:Yag laser vs. plastic curets + cotton pellets/sterilesaline + implantoplasty; defects grafted with abovine graft & resorbable porcine membrane;postop rinse 0.2%CHX twice/day/2 weeks

Human 5-yearNo microbiological testingN = 32 patients

Surgical access + decontamination withconventional debridement vs. CO2 laser. Defectsgrafted with beta-TCP + autogenous bone (50:50) orleft alone. Implants receiving grafts were screwretained only & covered with a non-resorbable Gore-Tex membrane & submerged 4 months

3.4. Surgical treatment of peri-implantitis without systemicantibiotics (Table 3)

Resective surgical therapy with osseous re-contouring, implantsurface debridement and decontamination, and apically re-positioned flaps has been shown to improve clinical parametersin a group of 30 individuals, however, complete resolution ofinflammation was almost never achieved at twelve months (DeWaal, Raghoebar, Huddleston Slater, Meijer, Winkel, & vanWinkelhoff, 2013). The authors noted greater immediate anaerobicbacterial reduction using 0.12% chlorhexidine for decontaminationthan the placebo solution (saline) but without superior clinical orradiological results at one year (De Waal et al., 2013). Sixty-six outof the 69 implants present at one year showed at least one site withbleeding on probing and 15 implants with additional suppuration.Treatment was only successful (residual pockets <5 mm with nobleeding and/or suppuration) for 11 patients (38%) and 38 (49%)implants (De Waal et al., 2013) .

A different 6 month study starting with 32 patients and thenfollowed for 4 years in 17 individuals reported no significantimpact of the method of surface decontamination, using Er:Yaglaser vs. plastic curets and cotton pellets/sterile saline, on the

Outcome Implantsystem

Author/Year

Complete resolution of inflammation almost neverachieved for both groupsGreater immediate anaerobic reduction with 0.12%CHX vs. saline decontamination but withoutsuperior clinical or radiological results at 1y.Treatment only successful (residual pockets <5 mmwith no bleeding and/or suppuration) for 11 patients(38%) and 38 implants (49%)

BrånemarkturnedAnodizedTiUnite NobelBiocareStraumannTPS,SLA, SLAactiveAstra TiOblastOsseospeedIMZ Titaniumplasma-sprayedGrit-blastedacid-etchedFriadent plus,Dentsply

De Waalet al.(2013)

Probing depth reductions accounted to 1.3 and1.2 mm and bleeding on probing to 23.5% and 14.8%for both groups, respectively. Due to suppurationand progressive bone loss 4 patients discontinue thestudy

Astra nanotypesurfaceBrånemarkturnedCamlogStraumann,microroughsurfaceKSI machineNobel replace,microroughsurfaceTapered ScrewVent, Zimmer,microroughsurfaceXive, DentsplyFriadent,microroughsurface

Schwarzet al.(2013)

A total of 13 implants (18%) removed. Inflammationreduced initially but increased again by the end ofthe study in every group No long-term differencesbetween the two protocols

IMZFrialit-2,FriadentBrånemarkturnedStraumann

Deppeet al.(2007)

46 F. Verdugo et al. / Archives of Oral Biology 64 (2016) 39–50

clinical outcomes after surgical treatment of advanced peri-implantitis lesions (Schwarz, Sahm, Iglhaut, & Becker, 2011;Schwarz, Hegewald, John, Sahm, & Becker, 2013). Probing depthsreduced by 1.3 and 1.2 mm and bleeding on probing reduced to23.5% and 14.8% for both groups, respectively. Implantoplasty wasperformed on all affected implants and bony defects grafted with abovine material. Due to suppuration and progressive bone loss fourpatients had to discontinue the study. The authors advised that thelong-term clinical stability could be influenced by factors otherthan the method of surface decontamination (Schwarz et al., 2011).

A 5-year clinical report on 32 patients with 73 ailing implantscompared the effects of decontamination using either convention-al debridement or CO2 laser. Defects were either grafted with beta-tricalcium phosphate + autogenous bone (50:50 ratio) or left alone(Deppe, Horch, & Neff, 2007). Implants were covered with a non-resorbable Gore-Tex membrane and submerged. Complications ofedema and severe and chronic infection, resulted in implant loss. Atotal of 13 implants (18%) were removed. Inflammation wasreduced initially but increased again by the end of the study inevery group. No microbiological or antibiotic susceptibility testingwas performed. Although CO2 laser may be more efficacious indeep, narrow bony defects, than conventional debridement, theauthors concluded that there were no differences in the long-termdecontamination effects between the two protocols (Deppe et al.,2007).

3.5. Summary of systematic review

For those few studies reporting microbiological data at follow-up, risk was defined as the persistence of specific periodontopathicbacteria at follow-up. Additionally, for those studies that did notreport such data, risk was evaluated as persistence of inflamma-tion, bleeding, suppuration and progressive bone loss or implantloss (Table 1).

The only two studies (Leonhardt et al., 2003; Mombelli & Lang,1992) with microbiological follow-up have demonstrated that,after surgical and non-surgical therapy with systemic antimicro-bials, opportunistic periodontopathic bacteria (enteric rods, E. coliand E. cloacae, A. actinomycetemcomitans, P. gingivalis) can reappearafter a period of time. Increasing the antibiotic regime to fourweeks is unlikely to prevent specific bacterial overgrowth eitherand re-treatment may become necessary (Leonhardt et al., 2003).Additionally, a combination of amoxicillin and metronidazole forseven days has shown that only 47% of the treated implants hadcomplete resolution of bleeding on probing at one year, withongoing bone loss in three patients and gastrointestinal dis-turbances in 25% of the total of 24 individuals treated (Heitz-Mayfield et al., 2012). Similarly, a group of 31 peri-implantitisindividuals showed only 48% with no signs of the disease (Serino &Turri, 2011). Thus, a strict personalized supportive maintenancetherapy may become critical in preventing disease recurrence,primarily, to keep the proportions of unwanted pathogens low andhelp sustain a normal ecological balance. A recent five-year follow-up study has shown the benefits of a 3-month recall program. Lowbleeding scores and no change or loss of bone in 10 out of the25 study individuals was reported (Roos-Jansåker et al., 2014).

Altogether, the existing limited scientific data suggests that theuse of systemic antimicrobials to treat peri-implantitis will nothelp generate stable long-term outcomes and could allow theovergrowth of superinfecting microorganisms. Opportunisticpathogens, such as S. aureus or EBV, may favor the conversion ofa normal symbiotic ecosystem into a dysbiotic ecosystem bydown-regulating the local innate immune response, thus, allowingthe overgrowth of superinfecting bacteria and yeast. Moreover, theemergence of antimicrobial resistance coupled with indiscrim-inative antibiotic administration could support the escalation of

peri-implant disease in years to come. Identifying opportunisticmicroorganisms, by means of microbial sampling, is essential topreventing superinfections. If systemic antibiotics are deemednecessary, an antimicrobial susceptibility test should be performedto minimize risks.

4. Discussion

The present review on risks associated with the use of systemicantibiotics in peri-implantitis treatment illustrates the importanceof adequate clinical and microbiological follow-up, microbiologicalsusceptibility testing and non-empiric antimicrobial regimens(Rams et al., 2014a; Rams et al., 2014b; Helovuo et al., 1993; Ramset al., 1990; Teles et al., 2008; Buchmann et al., 2000; Leonhardtet al., 2003). Thus far, there has been little documentation of thepotentially deleterious effects of broad-spectrum systemic anti-biotics use in peri-implant disease therapy.

This is due to the lack of studies with long-term microbiologicalfollow-up. The development of chronic peri-implant and peri-odontal superinfections is a complication that may initially beoverlooked but could lead to sustained progressive bone losscompromising dental implant outcomes (Emrani et al., 2009; vanWinkelhoff & Wolf, 2000; Teles et al., 2008; Buchmann et al., 2000;Leonhardt et al., 2003; Botero, González, Mercado, Olave, &Contreras, 2005). The deficiency of clear guidelines from peri-odontitis studies and paucity of scientific data from peri-implantitis research, on the use of systemic antibiotics, can leadto unsafe science-based clinical decisions.

With an estimated twelve million implants being placedannually worldwide, peri-implant bone loss has become, in thelast few years, a complication difficult to resolve (Esposito et al.,2012; Albrektsson et al., 2014). Factors such as excess of cement orpoorly fabricated implants handled by unqualified clinicians canworsen the prognosis and accelerate the progression of bone loss(Albrektsson et al., 2014; Qian et al., 2012; Wilson, 2009).

Clinically, the acknowledged and long-established risk factorsfor periodontitis may be considered as equivalent to those for peri-implantitis. Patients susceptible to periodontitis appear to be morevulnerable to peri-implantitis than those without a history of thedisease (Heitz-Mayfield & Lang, 2010). Regardless of the initiatingetiological factors, the disease process is exacerbated andmaintained by specific microbial infection with bacteria andpossibly yeasts and viruses (Rams et al., 2014a; Verdugo et al.,2015a; Verdugo et al., 2015b; Leonhardt et al.,1999; Heitz-Mayfield& Lang, 2010). Therefore, many clinicians have chosen to treat peri-implantitis as an infectious disease using broad-spectrum anti-biotics (Heitz-Mayfield et al., 2012; Emrani et al., 2009; vanWinkelhoff & Wolf, 2000; Leonhardt et al., 2003; Mombelli & Lang,1992; Serino & Turri, 2011; Khoury & Buchmann, 2001; Roos-Jansåker et al., 2007). Unfortunately, though systemic antimicro-bials have shown to improve therapy outcomes in aggressiveperiodontitis individuals (Sgolastra, Petrucci, Gatto, & Monaco,2012), time and indiscriminating empiric regimens have made therisk of antibiotic resistance development a reality (Rams et al.,2014a, 2014b; Poveda Roda, Bagan, Sanchis Bielsa, & CarbonellPastor, 2007).

The present review shows that every clinical study claimingmore or less successful therapy outcomes after treating peri-implantitis had, at follow-up, a sub-group of implants with eitherpersistent inflammation, residual pockets, suppuration, progres-sive bone loss or implants that had to be removed (Table 1). Mostclinicians performing grafting procedures, such as, guided boneregeneration to treat peri-implant defects, use antibiotics to avoidinfectious complications and membrane contamination (Khoury &Buchmann, 2001; Roos-Jansåker et al., 2007). Yet still, the rate ofinfectious complications was significant, between 44 and 60%. The

F. Verdugo et al. / Archives of Oral Biology 64 (2016) 39–50 47

estimated risk of contamination and infection in these circum-stances can be high due to the difficulty of eliminating 100% thepathogenic biofilm from the contaminated rough implant surface.Moreover, the typical patient population treated are likelysusceptible hosts with a past history of periodontitis, and mostclinicians do not perform a baseline and follow-up microbialsampling (Heitz-Mayfield et al., 2012; Serino & Turri, 2011; Roos-Jansåker et al., 2007; Roos-Jansåker et al., 2014; De Waal et al.,2013; Schwarz et al., 2011; Schwarz et al., 2013; Deppe et al., 2007).

To reduce the risks of microbial recontamination in thesesusceptible populations, personalized periodontal supportivetherapy might help prevent complications and peri-implantitisrelapses. A 3-month recall protocol has show positive outcomes atfive years in a small group of smoker patients with a past history ofperiodontal disease (Roos-Jansåker et al., 2007).

It is plausible to speculate that the rapid progression of boneloss in some studies or the persistent inflammation of others wasdue to infection with superinfecting agents resistant to antimicro-bials (Rams et al., 2014a; Verdugo et al., 2015b; Emrani et al., 2009;van Winkelhoff & Wolf, 2000; Leonhardt et al., 1999; Vincent-Bugnas et al., 2013; Slots, 2010; Leonhardt et al., 2003; Botero et al.,2005; Heitz-Mayfield & Lang, 2010). Previous studies haveidentified superinfecting agents, colonized in the peri-implantsubmucosa, displaying a remarkable antimicrobial resistance(Rams et al., 2014a; Emrani et al., 2009; van Winkelhoff & Wolf,2000; Helovuo et al.,1993; Leonhardt et al., 2003; Heitz-Mayfield &Lang, 2010). As a result, Candida and Staphylococcus spp., andenteric rods, among others, have been frequently isolated fromperi-implantitis lesions (Leonhardt et al., 1999; Leonhardt et al.,2003). Microbiological culture monitoring and antibiotic suscepti-bility testing could prevent the emergence of implant super-infections in susceptible individuals harboring microorganismssuch as E. coli and E. cloacae at baseline (Leonhardt et al., 2003).

The individual human indigenous microbiota or normalmicroflora is fairly constant at each ecological habitat (Sullivanet al., 2001). The normal human microflora acts as a barrier againstcolonization by opportunistic microorganisms or overgrowth ofalready present pathogens like yeasts, Clostridium difficile, orenteric rods. Overgrowth control of opportunistic pathogens, alsocalled colonization resistance, is maintained not only by thenormal indigenous microflora, but also by different physiologicalfactors such as secretion of saliva and gastric acid (Sullivan et al.,2001; Rashid et al., 2012). If we could use only antimicrobials thatdo not alter colonization resistance, then the risk of developmentand spread of resistant strains among patients, and disseminationof resistant elements between pathogens, would be minimized(Rashid et al., 2012).

C. albicans may be particularly difficult to eradicate due to itscapacity to invade host tissues, form hyphae, and ability to interactwith commensal bacteria to synergistically stimulate its virulence(Martin et al., 2011; Xu et al., 2014). Quick antimicrobial therapyshould be delivered when a clinical or subclinical candidiasis isdetected. Prolonged C. albicans infection could induce chronictissue destruction through pro-inflammatory cytokine up-regula-tion (Xu et al., 2014; Dongari-Bagtzoglou et al., 2004). This cytolyticactivity could trigger interleukin IL-1alpha release from yeast-infected oral epithelial cells, increasing cytokine secretion fromuninfected epithelial cells, and thus creating a vicious cycle(Dongari-Bagtzoglou et al., 2004).

The genera of the enterobacteriaceae, a family of Gram-negativefacultative anaerobic rod-shaped bacteria, are among the mostpathogenic and commonly found microorganisms in clinicalmicrobiology (Sanders & Sanders, 1997). Risks that can lead tothe development of these superinfecting agents include, amongother factors, prolonged hospital stay, immunosuppression, nail-biting, use of contaminated toothbrushes and the presence of a

foreign device such as an implant (Sanders & Sanders,1997; Baydaşet al., 2007; Bezirtzoglou et al., 2008). Enterobacter species alsohave a reputation for their ability to develop multidrug resistanceto a number of broad-spectrum antibiotics such as beta-lactamantibiotics, tetracycline, aminoglycosides or even quinolones(Sanders & Sanders, 1997; Choi et al., 2008; Naesens et al., 2009).

Combination antibiotic regimens of amoxicillin and metroni-dazole for 7 days have yielded significant qualitative andquantitative alterations in the normal human indigenous micro-flora, and generated shifts from susceptible to resistant strains andovergrowth of yeast and resistant enterobacteriaceae withpersistence of resistant strains 4 weeks after administration(Adamsson, Nord, Lundquist, Sjöstedt, & Edlund, 1999). Heitz-Mayfield et al. (2012) reported in their study that the use ofsystemic amoxicillin and metronidazole was associated withgastrointestinal disturbances in 25% of the study population. Theyalso reported that, despite 92% of implants showing stable crestalbone levels, only 47% of the treated implants had completeresolution of bleeding on probing and three patients, out of 24 peri-implantitis individuals, continued to show ongoing bone loss at the12-month follow-up. No microbiological evaluation was per-formed (Heitz-Mayfield et al., 2012). In contrast, microbiologicalmonitoring and antibiotic susceptibility testing prevented theemergence of implant superinfections in susceptible patientsharboring enteric rods and A. actinomycetemcomitans at baseline,and yet, pathogenic bacteria were still present in 53% of theaffected sites at five years (Leonhardt et al., 2003). Changing theantibiotic regime to 4 weeks did not improve the microbiologicalparameters, re-treatment was often necessary, and 27% of thestudy implants were lost or continued to lose bone during the 5-year follow-up (Leonhardt et al., 2003).

The mixed microbiota of peri-implantitis lesions resemblessomehow that of periodontal infections, but with some significantdifferences. The peri-implant and periodontal microbiomesrepresent microbiologically distinct ecosystems. A significantdifference is the frequent presence of higher proportions ofstaphylococci and enteric bacteria in peri-implantitis lesions(Belibasakis, 2014; Charalampakis & Belibasakis, 2015). Themicrobial diversity infecting peri-implantitis lesions versushealthy implants is complex and could harbor well over 40 differ-ent genera per sample site of mostly Gram negative and positiveanaerobic opportunistic pathogens and Epstein-Barr virus (Kumar,Mason, Brooker, & O’Brien, 2012; da Silva et al., 2014; Rakic,Grusovin, & Canullo, 2015). Pyrosequencing and Sanger sequencingtechnology have allowed to identifying large arrays of bacteriainfecting peri-implantitis lesions and have shown distinct differ-ences between health and disease. Peri-implantitis seems to be amore microbiologically heterogeneous infection with primarilyGram-negative species and less complex microbiota than peri-odontitis (Kumar et al., 2012).

Considering the average sizes of 0.5–2 mm for most super-infecting bacteria, such as, Enterobacter or Staphylococcus species,and the matching rough implant surfaces micro pits, successfulpathogen eradication seems a questionable quest (Charalampakiset al., 2014). Moderately rough implant surfaces would likely favorthe thriving of superinfecting agents after empiric antibioticregimens. The combination of mechanical and chemical decon-tamination, in healthy subjects, has failed to eradicate bacterialbiofilms from easily accessible titanium discs after only a short 4-day exposure (Charalampakis et al., 2014).

The presence of EBV seems more likely at peri-implantitislesions than healthy implants and even saliva for the sameindividual (Verdugo et al., 2015b). Epstein-Barr virus, as a potentialsuperinfecting agent, can complicate therapy outcomes due to itscapacity to block local neutrophil innate response, affect/infectendothelial cells and damage implant biologic width (Vincent-

48 F. Verdugo et al. / Archives of Oral Biology 64 (2016) 39–50

Bugnas et al., 2013; Kato et al., 2013; Larochelle et al., 1998; Farinaet al., 2014; Savard & Gosselin, 2006). Successful treatment of EBV-associated severe periodontitis using valacyclovir 500 mg/day for10 days has been documented (Sunde, Olsen, Enersen, & Grinde,2008). Therefore, antiviral therapy could be considered in futureresearch protocols for EBV-associated peri-implantitis. Eliminationof herpesviruses from periodontal and peri-implant sites mayimprove individual oral health status and reduce the frequency ofherpesvirus viremia and salivary transmission, possibly loweringthe risk of serious medical diseases and disabilities (Slots, 2015).

A key aspect in peri-implantitis would be to establish preciseand personalized maintenance protocols, eliminate reservoirs ofpathogenic bacteria, particularly on those with past history ofperiodontitis (Roos-Jansåker et al., 2014; Van Winkelhoff, 2012),and frequently evaluate individual microbial profiles so that earlyclinical changes can be monitored and potential risks reduced. It iswell documented that superinfecting agents, such as, Enterobacter,Candida, or Staphylococcus species, can significantly thrive after theadministration of systemic antibiotics (Sullivan et al., 2001;Helovuo et al., 1993; Rashid et al., 2012; Adamsson et al., 1999).Systemic antimicrobials can negatively affect the protectiveoropharyngeal microflora by altering a delicate ecological balanceand favoring the overgrowth of opportunistic pathogens (Sullivanet al., 2001; Rashid et al., 2012; Adamsson et al., 1999).

The increased use of dental implants worldwide coupled withthe upraise of antimicrobial resistance and indiscriminativeantibiotic administration, is likely to support the escalation ofperi-implant disease in years to come, with an already estimatedprevalence of nearly 56% (Lindhe et al., 2008).

An effort should be made to monitor and revise patients’medical history regularly, tracking past antibiotic use, smokinghabits and diabetes status, among other conditions, and considerthe use of probiotics to protect the normal microflora, in order tohelp prevent peri-implant superinfection emergence. Furtherstudies, particularly randomized clinical trials, are urgently neededto develop effective antimicrobial and maintenance protocols inperi-implantitis patients, to identify individuals at risk, and tounderstand the potential role of superinfecting pathogens in theprogression of peri-implant bone loss.

5. Conclusion

There is no proven effective treatment protocol to maintainperi-implatitis patients free of inflammation long-term. Peri-implant superinfections are a potential risk associated with broad-spectrum antibiotics in immunocompetent individuals. Non-responsive to treatment peri-implantitis lesions, associated withrapidly progressive bone loss, are possibly induced and aggravatedby superinfecting agents. Lack of follow-up, antibiotic susceptibil-ity testing, and indiscriminating empiric treatment regimens maylead to specific ongoing microbial challenge that can exacerbateand maintain the disease progression. Personalized 3-monthsupportive therapy may help prevent risks by decreasing specificpathogen proportions and maintaining optimal plaque control.

Conflict of interest

None. All authors have read and approved the final article.

Author contribution

Each author performed the following tasks:1. F. Verdugo: Inception of concept & study design; data

collection/analysis & interpretation of collected scientific data;drafting of article; critical revision of article at all stages & finalrevision & approval. Accountable for all aspects of the work and

will ensure that questions related to the accuracy or integrity of thestudy are appropriately investigated and resolved.

2. T. Laksmana: (1) Acquisition, analysis & interpretation ofcollected data; (2) critical revision of paper; (3) final revision andapproval of paper; (4) agree to be accountable for all aspects of thework.

3. A. Uribarri: (1) Acquisition & analysis of scientific data; (2)critical revision of paper; (3) final revision and approval of paper;(4) agree to be accountable for all aspects of the work.

Funding

None.

Competing interest

None.

Ethical approval

Not required.

References

Adamsson, I., Nord, C. E., Lundquist, P., Sjöstedt, S., & Edlund, C. (1999). Comparativeeffects of omeprazole, amoxycillin plus metronidazole versus omeprazole,clarithromycin plus metronidazole on the oral, gastric and intestinal microflorain Helicobacter pylori-infected patients. Journal of Antimicrobial Chemotherapy,44, 629–640.

Albouy, J. P., Abrahamsson, I., & Berglundh, T. (2012). Spontaneous progression ofexperimental peri-implantitis at implants with different surfacecharacteristics: an experimental study in dogs. Journal of Clinical Periodontology,39, 182–187.

Albrektsson, T., Zarb, G., Worthington, P., & Ericsson, A. (1986). The long-termefficacy of currently used dental implants: a review and proposed criteria forsuccess. International Journal of Oral & Maxillofacial Implants, 1, 11–25.

Albrektsson, T., Dahlin, C., Jemt, T., Sennerby, L., Turri, A., & Wennerberg, A. (2014). Ismarginal bone loss around oral implants the result of a provoked foreign bodyreaction??. Clinical Implant Dentistry and Related Research, 16, 155–165.

Anderl, J. N., Zahller, J., Roe, F., & Stewart, P. S. (2003). Role of nutrient limitation andstationary phase existence in Klebsiella pneumoniae biofilm resistance toampicillin and ciprofloxacin. Antimicrobial Agents and Chemotherapy, 47, 1251–1256.

Baydaş, B., Uslu, H., Yavuz, I., Ceylan, I., & Da�gsuyu, I. M. (2007). Effect of a chronicnail-biting habit on the oral carriage of Enterobacteriaceae. Oral Microbiologyand Immunology, 22, 1–4.

Belibasakis, G. N. (2014). Microbiological and immuno-pathological aspects of peri-implant diseases. Archives of Oral Biology, 59, 66–72.

Berglundh, T., Gotfredsen, K., Zitzmann, N. U., Lang, N. P., & Lindhe, J. (2007).Spontaneous progression of ligature induced peri-implantitis at implants withdifferent surface roughness: an experimental study in dogs. Clinical OralImplants Research, 18, 655–661.

Bezirtzoglou, E., Cretoiu, S. M., Moldoveanu, M., Alexopoulos, A., Lazar, V., & Nakou,M. (2008). A quantitative approach to the effectiveness of ozone againstmicrobiota organisms colonizing toothbrushes. Journal of Dentistry, 36, 600–605.

Botero, J. E., González, A. M., Mercado, R. A., Olave, G., & Contreras, A. (2005).Subgingival microbiota in peri-implant mucosa lesions and adjacent teeth inpartially edentulous patients. Journal of Periodontology, 76, 1490–1495.

Buchmann, R., Müller, R. F., Heinecke, A., & Lange, D. E. (2000). Actinobacillusactinomycetemcomitans in destructive periodontal disease. Three-year follow-up results. Journal of Periodontology, 71, 444–453.

Charalampakis, G., & Belibasakis, G. N. (2015). Microbiome of peri-implantinfections: lessons from conventional, molecular and metagenomic analyses.Virulence, 6, 183–187.

Charalampakis, G., Ramberg, P., Dahlén, G., Berglundh, T., & Abrahamsson, I. (2014).Effect of cleansing of biofilm formed on titanium discs. Clinical Oral ImplantsResearch. http://dx.doi.org/10.1111/clr.12397 [Epub ahead of print].

Choi, S. H., Lee, J. E., Park, S. J., Choi, S. H., Lee, S. O., Jeong, J. Y., et al. (2008).Emergence of antibiotic resistance during therapy for infections caused byEnterobacteriaceae producing AmpC beta-lactamase: implications forantibiotic use. Antimicrobial Agents and Chemotherapy, 52, 995–1000.

da Silva, E. S., Feres, M., Figueiredo, L. C., Shibli, J. A., Ramiro, F. S., & Faveri, M. (2014).Microbiological diversity of peri-implantitis biofilm by Sanger sequencing.Clinical Oral Implants Research, 25, 1192–1199.

De Waal, Y. C., Raghoebar, G. M., Huddleston Slater, J. J., Meijer, H. J., Winkel, E. G., &van Winkelhoff, A. J. (2013). Implant decontamination during surgical peri-implantitis treatment: a randomized, double-blind, placebo-controlled trial.Journal of Clinical Periodontology, 40, 186–195.

F. Verdugo et al. / Archives of Oral Biology 64 (2016) 39–50 49

Deppe, H., Horch, H. H., & Neff, A. (2007). Conventional versus CO2 laser-assistedtreatment of peri-implant defects with the concomitant use of pure-phase beta-tricalcium phosphate: a 5-year clinical report. International Journal of Oral &Maxillofacial Implants, 22, 79–86.

Dongari-Bagtzoglou, A., Kashleva, H., & Villar, C. C. (2004). Bioactive interleukin-1alpha is cytolytically released from Candida albicans-infected oral epithelialcells. Medical Mycology, 42, 531–541.

Eick, S., & Pfister, W. (2004). Efficacy of antibiotics against periodontopathogenicbacteria within epithelial cells: an in vitro study. Journal of Periodontology, 75,1327–1334.

Emrani, J., Chee, W., & Slots, J. (2009). Bacterial colonization of oral implants fromnondental sources. Clinical Implant Dentistry and Related Research, 11, 106–112.

Esposito, M., Grusovin, M. G., & Worthington, H. V. (2012). Treatment of peri-implantitis: what interventions are effective? A Cochrane systematic review.European Journal of Oral Implantology, 5, S21–41.

Farina, A., Cirone, M., York, M., Lenna, S., Padilla, C., McLaughlin, S., et al. (2014).Epstein-Barr virus infection induces aberrant TLR activation pathway andfibroblast-myofibroblast conversion in scleroderma. Journal of InvestigativeDermatology, 134, 954–964.

Feres, M., Figueiredo, L. C., Soares, G. M., & Faveri, M. (2015). Systemic antibiotics inthe treatment of periodontitis. Periodontol. 2000, 67, 131–186.

Haffajee, A. D., Socransky, S. S., & Gunsolley, J. C. (2003). Systemic anti-infectiveperiodontal therapy. A systematic review. Annals of Periodontology, 8, 115–181.

Hallström, H., Persson, G. R., Lindgren, S., Olofsson, M., & Renvert, S. (2012). Systemicantibiotics and debridement of peri-implant mucositis. A randomized clinicaltrial. Journal of Clinical Periodontology, 39, 574–581.

Heitz-Mayfield, L. J., & Lang, N. P. (2010). Comparative biology of chronic andaggressive periodontitis vs. peri-implantitis. Periodontol. 2000, 53, 167–181.

Heitz-Mayfield, L. J., Salvi, G. E., Mombelli, A., Faddy, M., Lang, N. P., & ImplantComplication Research Group (2012). Anti-infective surgical therapy of peri-implantitis. A 12-month prospective clinical study. Clinical Oral ImplantsResearch, 23, 205–210.

Helovuo, H., Hakkarainen, K., & Paunio, K. (1993). Changes in the prevalence ofsubgingival enteric rods, staphylococci and yeasts after treatment withpenicillin and erythromycin. Oral Microbiology and Immunology, 8, 75–79.

Herrera, D., Alonso, B., León, R., Roldán, S., & Sanz, M. (2008). Antimicrobial therapyin periodontitis: the use of systemic antimicrobials against the subgingivalbiofilm. Journal of Clinical Periodontology, 35(8S), 45–66.

Iwase, M., Slots, J., Berthold, P., & Taichman, N. S. (1990). Leukocidal activity ofstaphylococci isolated from human periodontal lesions. Oral Microbiology andImmunology, 5, 233–236.

Kato, A., Imai, K., Ochiai, K., & Ogata, Y. (2013). Higher prevalence of Epstein-Barrvirus DNA in deeper periodontal pockets of chronic periodontitis in Japanesepatients. PLoS One, 26(8), e71990.

Khoury, F., & Buchmann, R. (2001). Surgical therapy of peri-implant disease: a 3-year follow-up study of cases treated with 3 different techniques of boneregeneration. Journal of Periodontology, 72, 1498–1508.

Kumar, P. S., Mason, M. R., Brooker, M. R., & O'Brien, K. (2012). Pyrosequencingreveals unique microbial signatures associated with healthy and failing dentalimplants. Journal of Clinical Periodontology, 39, 425–433.

Larochelle, B., Flamand, L., Gourde, P., Beauchamp, D., & Gosselin, J. (1998). Epstein-Barr virus infects and induces apoptosis in human neutrophils. Blood, 92, 291–299.

Leonhardt, A., Renvert, S., & Dahlén, G. (1999). Microbial findings at failing implants.Clinical Oral Implants Research, 10, 339–345.

Leonhardt, A., Dahlén, G., & Renvert, S. (2003). Five-year clinical, microbiological,and radiological outcome following treatment of peri-implantitis in man.Journal of Periodontology, 74, 1415–1422.

Lindhe, J., Meyle, J., & Group D of European Workshop on Periodontology (2008).Peri-implant diseases: Consensus Report of the Sixth European Workshop onPeriodontology. Journal of Clinical Periodontology, 35(Suppl. 8), 282–285.

Máximo, M. B., de Mendonça, A. C., Renata Santos, V., Figueiredo, L. C., Feres, M., &Duarte, P. M. (2009). Short-term clinical and microbiological evaluations ofperi-implant diseases before and after mechanical anti-infective therapies.Clinical Oral Implants Research, 20, 99–108.

Mah, T. F., Pitts, B., Pellock, B., Walker, G. C., Stewart, P. S., & O'Toole, G. A. (2003). Agenetic basis for Pseudomonas aeruginosa biofilm antibiotic resistance. Nature,426(6964), 306–310.

Marsh, P. D. (2005). Dental plaque: biological significance of a biofilm andcommunity life-style. Journal of Clinical Periodontology, 32, 7–15.

Martin, R., Wächtler, B., Schaller, M., Wilson, D., & Hube, B. (2011). Host–pathogeninteractions and virulence-associated genes during Candida albicans oralinfections. International Journal of Medical Microbiology, 301, 417–422.

Mellado-Valero, A., Buitrago-Vera, P., Solá-Ruiz, M. F., & Ferrer-García, J. C. (2013).Decontamination of dental implant surface in peri-implantitis treatment: aliterature review. Medicina Oral Patologia Oral y Cirugia Bucal, 18, e869–e876.

Mombelli, A., & Lang, N. P. (1992). Antimicrobial treatment of peri-implantinfections. Clinical Oral Implants Research, 3, 162–168.

Naesens, R., Ursi, J. P., Van Schaeren, J., & Jeurissen, A. (2009). In vitro activity oftigecycline against multidrug-resistant Enterobacteriaceae isolates from aBelgian hospital. European Journal of Clinical Microbiology & Infectious Diseases,28, 381–384.

Persson, G. R., Samuelsson, E., Lindahl, C., & Renvert, S. (2010a). Mechanical non-surgical treatment of peri-implantitis: a single-blinded randomizedlongitudinal clinical study. II. Microbiological results. Journal of ClinicalPeriodontology, 37, 563–573.

Persson, G. R., Samuelsson, E., Lindahl, C., & Renvert, S. (2010b). Mechanical non-surgical treatment of peri-implantitis: a single-blinded randomizedlongitudinal clinical study. II. Microbiological results. Journal of ClinicalPeriodontology, 37, 563–573.

Poveda Roda, R., Bagan, J. V., Sanchis Bielsa, J. M., & Carbonell Pastor, E. (2007).Antibiotic use in dental practice. A review. Medicina Oral Patologia Oral y CirugiaBucal, 12, E186–E192.

Qian, J., Wennerberg, A., & Albrektsson, T. (2012). Reasons for marginal bone lossaround oral implants. Clinical Implant Dentistry and Related Research, 14, 792–807.

Rakic, M., Grusovin, M. G., & Canullo, L. (2015). The microbiologic profile associatedwith peri-implantitis in humans: a systematic review. International Journal ofOral & Maxillofacial Implants. http://dx.doi.org/10.11607/jomi.4150.

Rams, T. E., Babalola, O. O., & Slots, J. (1990). Subgingival occurrence of enteric rods,yeasts and staphylococci after systemic doxycycline therapy. Oral Microbiologyand Immunology, 5, 166–168.

Rams, T. E., Degener, J. E., & van Winkelhoff, A. J. (2014a). Antibiotic resistance inhuman peri-implantitis microbiota. Clinical Oral Implants Research, 25, 82–90.

Rams, T. E., Degener, J. E., & van Winkelhoff, A. J. (2014b). Antibiotic resistance inhuman chronic periodontitis microbiota. J Periodontol, 85, 160–169.

Rashid, M. U., Weintraub, A., & Nord, C. E. (2012). Effect of new antimicrobial agentson the ecological balance of human microflora. Anaerobe, 18, 249–253.

Roberts, A. P., & Mullany, P. (2006). Genetic basis of horizontal gene transfer amongoral bacteria. Periodontol. 2000, 42, 36–46.

Roberts, A. P., Pratten, J., Wilson, M., & Mullany, P. (1999). Transfer of a conjugativetransposon, Tn5397 in a model oral biofilm. FEMS Microbiology Letters, 177, 63–66.

Roos-Jansåker, A. M., Revert, H., Lindahl, C., & Revert, S. (2007). Surgical treatment ofperi-implantitis using a bone substitute with or without a resorbablemembrane: a prospective cohort study. Journal of Clinical Periodontology, 34,625–632.

Roos-Jansåker, A. M., Persson, G. R., Lindahl, C., & Renvert, S. (2014). Surgicaltreatment of peri-implantitis using a bone substitute with or without aresorbable membrane: a 5-year follow-up. Journal of Clinical Periodontology, 41,1108–1114.

Sanders, W. E. Jr., & Sanders, C. C. (1997). Enterobacter spp.: pathogens poised toflourish at the turn of the century. Clinical Microbiology Reviews, 10, 220–241.

Savard, M., & Gosselin, J. (2006). Epstein-Barr virus immunossuppression of innateimmunity mediated by phagocytes. Virus Research, 119, 134–145.

Schwarz, F., Sahm, N., Iglhaut, G., & Becker, J. (2011). Impact of the method of surfacedebridement and decontamination on the clinical outcome following combinedsurgical therapy of peri-implantitis: a randomized controlled clinical study.Journal of Clinical Periodontology, 38, 276–284.

Schwarz, F., Hegewald, A., John, G., Sahm, N., & Becker, J. (2013). Four-year follow-upof combined surgical therapy of advanced peri-implantitis evaluating twomethods of surface decontamination. Journal of Clinical Periodontology, 40, 962–967.

Serino, G., & Turri, A. (2011). Outcome of surgical treatment of peri-implantitis:results from a 2-year prospective clinical study in humans. Clinical Oral ImplantsResearch, 22, 1214–1220.

Sgolastra, F., Petrucci, A., Gatto, R., & Monaco, A. (2012). Effectiveness of systemicamoxicillin/metronidazole as an adjunctive therapy to full-mouth scaling androot planing in the treatment of aggressive periodontitis: a systematic reviewand meta-analysis. Journal of Periodontology, 83, 731–743.

Slots, J. (2010). Herpesviral-bacterial interactions in periodontal diseases.Periodontol. 2000, 52, 117–140.

Slots, J. (2015). Periodontal herpesviruses: prevalence, pathogenicity, systemic risk.Periodontol. 2000, 69, 28–45.

Sullivan, A., Edlund, C., & Nord, C. E. (2001). Effect of antimicrobial agents on theecological balance of human microflora. Lancet Infectious Diseases, 1, 101–114.

Sunde, P. T., Olsen, I., Enersen, M., & Grinde, B. (2008). Patient with severeperiodontitis and subgingival Epstein-Barr virus treated with antiviral therapy.Journal of Clinical Virology, 42, 176–178.

Teles, R. P., Patel, M., Socransky, S. S., & Haffajee, A. D. (2008). Disease progression inperiodontally healthy and maintenance subjects. Journal of Periodontology, 79,784–794.

Van Winkelhoff, A. J. (2012). Antibiotics in the treatment of peri-implantitis.European Journal of Oral ImplantologyS43–S50.

van Winkelhoff, A. J., & Wolf, J. W. (2000). Actinobacillus actinomycetemcomitans-associated peri-implantitis in an edentulous patient. A case report. Journal ofClinical Periodontology, 27, 531–535.

Verdugo, F., Castillo, A., Simonian, K., Russo, P., D’Addona, A., Raffaelli, L., et al.(2012). Periodontopathogen and Epstein-Barr virus contamination affectstransplanted bone volume in sinus augmentation. Journal of Periodontology, 83,162–173.

Verdugo, F., Castillo, A., Simonian, K., Castillo, F., Farez-Vidal, E., & D’addona, A.(2015a). Periodontopathogen and Epstein-Barr virus associated periapicalperiodontitis may be the source of retrograde infectious peri-impantitis. ClinicalImplant Dentistry and Related Research, 17, 199–207.

Verdugo, F., Castillo, A., Simonian, K., Castillo, F., Farez-Vidal, E., & D’addona, A.(2015b). Periodontopathogen and Epstein-Barr virus associated periapicalperiodontitis may be the source of retrograde infectious peri-impantitis. ClinicalImplant Dentistry and Related Research, 17, 199–207.

Verdugo, F., Castillo, A., Castillo, F., & Uribarri, A. (2015). Epstein-Barr virusassociated peri-implantitis: a split-mouth study. Clinical Oral Investigations, 19,535–543.

50 F. Verdugo et al. / Archives of Oral Biology 64 (2016) 39–50

Vincent-Bugnas, S., Vitale, S., Mouline, C. C., Khaali, W., Charbit, Y., Mahler, P., et al.(2013). EBV infection is common in gingival epithelial cells of the periodontiumand worsens during chronic periodontitis. PLoS One, 19(8), e80336.

Warburton, P. J., Palmer, R. M., Munson, M. A., & Wade, W. G. (2007). Demonstrationof in vivo transfer of doxycycline resistance mediated by a novel transposon.Journal of Antimicrobial Chemotherapy, 60, 973–980.

Weigel, L. M., Clewell, D. B., Gill, S. R., Clark, N. C., McDougal, L. K., Flannagan, S. E., etal. (2003). Genetic analysis of a high-level vancomycin-resistant isolate ofStaphylococcus aureus. Science, 302, 1569–1571.

Wilson, T. G. Jr. (2009). The positive relationship between excess cement and peri-implant disease: a prospective clinical endoscopic study. Journal ofPeriodontology, 80, 1388–1392.

Xu, H., Sobue, T., Thompson, A., Xie, Z., Poon, K., Ricker, A., et al. (2014). Streptococcalco-infection augments Candida pathogenicity by amplifying the mucosalinflammatory response. Cellular Microbiology, 16, 214–231.

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