Original Article An Investigation of Antibiotic Resistance of Aggregatibacter Actinomycetemcomitans and Porphyromonas Gingivalis in Peri-implantitis Lesions Z. Kadkhoda 1, S. Torabi 2, A. Aliramezani 3. 1 Associate Professor, Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran 2 Assistant Professor, Department of Periodontics, School of Dentistry, Qazvin University of Medical Sciences, Qazvin, Iran 3 PhD Student, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Abstract Background and Aim: It has been shown that anaerobic and capnophilic bacteria play an important role in implant failure and loss. The present study is an in vitro research aimed to investigate the antibiotic resistance of Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) in peri-implantitis lesions of Iranian patients and to find laboratory efficiency of some antibiotic on these two bacteria. Materials and Methods: In this antibiogram study, the plaque samples were obtained from peri-implantitis lesions from patients who referred to implant center of Faculty of Dentistry of Tehran University of Medical Sciences. Nine samples incubated in Aa-specific culture media and 9 samples incubated in Pg-specific culture media under anaerobic and capnophilic conditions. After 48 hours, colonies were verified by microscopic and biomedical examination, and a colony-counting device. Then the specimens were cultured in the specific culture media for antibiogram evaluations by measuring the diameter of growth inhibition zone of antibiotic standard disks of amoxicillin, co-amoxiclav, metronidazole, tetracycline, clindamycin, and ciprofloxacin. Results: There was no statistically significant difference (P=0.74) between the colony count of Aa (84.56±16.65) and Pg (87.67± 21.49). Most of growth inhibition zone ranged between 10 and 35 mm. The Pg specimens were significantly more resistant to studied antibiotics (P0.05) compared to Aa. However, both groups had similar resistance to amoxicillin and tetracycline, P-values were 0.22 and 0.13 respectively. Conclusion: A large number of peri-implantitis lesions contain Aa and Pg bacteria. Moreover, the majority of Aa samples were sensitive to the applied antibiotics, while Corresponding author: almost all Pg specimens were resistant to them. S. Torabi, Assistant Professor, Department of Periodontics, Key Words: Peri-implantitis, Antibacterial Drug Resistance, Aggregatibacter School of Dentistry, Qazvin actinomycetemcomitans, Porphyromonas gingivalis University of Medical Sciences, Qazvin, Iran Downloaded from jidai.ir at 1:20 +0330 on Monday September 27th 2021 [ DOI: 10.30699/jidai.29.4.135 ] Cite this article as: Kadkhoda Z, Torabi S, Aliramezani A. An Investigation of Antibiotic Resistance of [email protected] Aggregatibacter Actinomycetemcomitans and Porphyromonas Gingivalis in Peri-implantitis Lesions. J Islam Dent Assoc Iran. 2017; 29(4):135-140. DOI: 10.30699/jidai.29.4.135 Received: 2 Feb 2017 Accepted: 28 Sep 2017 Introduction depth around the implant and appears by bleeding Peri-implantitis is the condition of pathological and/or pus during probing [1]. Although the inflammatory changes that occur in the soft and etiology of peri-implantitis has not been clearly hard tissues around an implant. It is a progressive identified, environmental factors, such as infected inflammatory destruction of the alveolar bone, dental implants, cigarette smoking, history of which presents as deepening of the pocket probing periodontal disease, the implant soft-tissue Autumn 2017; Vol. 29, No. 4 135 Journal of Islamic Dental Association of IRAN (JIDAI) Autumn 2017 ;29, (4) Kadkhoda et. al interface, genetic factors, systemic diseases, poor peri-implantitis lesions, especially in the case of oral hygiene, lack of frequent dental visits, Aa and Pg probably due to difficulties of anaerobic immune system imbalance, and diabetes are microbial culture techniques. Many clinicians considered risk factors in its occurrence [2]. prefer to use variations of antibiotic regimens for It has been suggested that the tissues surrounding treatment of peri-implantitis lesions without any the implant have weaker natural barriers, and less antibiotic sensitivity tests such as antibiogram test. resistant to infection, compared to those of a tooth In the present study, we have investigated the [3]. Bacterial infection plays an important role in sensitivity of Aa and Pg to some of the antibiotics oral implant failure. The bacterial flora that is by antibiogram test. Results of such studies could present in peri-implantitis is similar to the flora help clinicians to consider some microbial resistant that is observed in periodontal diseases [4]. and choose a suitable antibiotic regimen as an Previous studies have shown that the bacterial flora adjunctive treatment to the mechanical therapy of in failing implants is gram-negative anaerobic peri-implantitis treatment. bacteria, such as Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), and Aggregatibacter Materials and Methods actinomycetemcomitans (Aa), which are also This research was an in-vitro antibiogram study of pathogens of periodontal disease [1]. The specimens collected from peri-implantitis lesions composition of microbial flora present in of patients who treated in the implant center of the peri-implantitis is far more complicated than that School of Dentistry, Tehran University of Medical which is found around healthy implants [5], Sciences (Ethics Committee approval number: Prevalence of peri-implantitis in patients with im- IR-TUMS.REC.1395-2819). Peri-implantitis plants and in implants themselves has been lesions in the patients were previously diagnosed reported as 18.8% and 9.6%, respectively [6]. by a trained periodontist and prosthodontist and The main treatment goals of peri-implant diseases referred to the implant center for sampling and are control of the infection and preventing disease laboratory study. The inclusion criteria were: to progression. Previous studies have reported have at least one peri-implantitis lesion in either successful treatment of peri-implantitis through upper or lower jaw; a minimum of 6 months and antimicrobial regimens in combination with maximum of two years since the implant have been surgical or non-surgical debridement [7]. loaded; no antibiotics consumptions for at least a Amoxicillin and clavulanic acid were month prior to the study; and absence of any recommended for surgical treatment of severe systemic diseases. After obtaining consent peri-implantitis because of some bacterial from the patients and before treatment, lesions with pathogen can potentially complicate these lesions a probing depth of ≥5 mm were examined via x- [8]. Amoxiclav (or amoxicillin and clavulanic ray in order to identify the bone defects and lesions acid) is used in the treatment of infections when with proximal bone loss of two implant threads we have some mixed infection and some resistant were selected for the study. In the present study, to first and general antibiotic therapy (without there was no need for matching the oral hygiene of using any antibiogram). patients and only the presence and detection of Aa Downloaded from jidai.ir at 1:20 +0330 on Monday September 27th 2021 [ DOI: 10.30699/jidai.29.4.135 ] Rams et al. [2] studied some bacterial resistance in and Pg was required. the peri-implantitis lesions and found that at in Samples were collected from each patient after vitro conditions, Prevotella intermedia/nigrescens isolating and cleaning the peri-implantitis lesion by or Streptococcus constellatus were resistant to inserting a sterile paper point in the pockets for 10 clindamycin, amoxicillin, doxycycline, and seconds. The paper points were immediately metronidazole in 46.7%, 39.2%, 25%, and 21.7% placed in thioglycolate medium and transferred to of the peri-implantitis subjects, respectively. In the the laboratory. In the laboratory, samples were in vitro conditions, only 6.7% subjects revealed incubated in Brucella agar medium enriched with resistant to both amoxicillin and metronidazole [2]. sheep blood, vitamin K, hemin, and horse and calf There are not enough laboratory documents about serum for less than half an hour. At this point microbial resistance to antibiotic therapy in patients and cultures were examined, however, not 136 Autumn 2017; Vol. 29, No. 4 Kadkhoda et. al An Investigation of Antibiotic Resistance of … all specimens grew on the anaerobic culture Antibiotic standard disks (mast disc, Mast group medium. Unfortunately, only a few of the Ltd, UK) of amoxicillin (10μg), co-amoxiclav specimens responded to the anaerobic culture (20μg), metronidazole (5μg), tetracycline medium. Successful specimens were frozen and 18 (10μg), clindamycin (10μg), and ciprofloxacin samples were prepared for further experiments, 9 (5 μg) (8,9) were placed on the agar surface. The on Aa and 9 on Pg specific culture medium. plates were incubated for further 48 hours followed Therefore, the sample size was less than it was by measuring the diameter of the inhibition zone in expected because of samples that failed to culture millimeters. due to the sensitivity of anaerobic bacteria to The collected data from colony counting and atmosphere’s O2 during sampling and/or antibiogram test were analyzed using Statistical transferring, or delicacy of their culture conditions. Package for the Social Sciences software, version The Aa-specific