Effects of a Single and Low Dose of Mifepristone on Integrin Expression in Human Endometrium During the Peri-implantation Period

Objective In order to gain further information about the mechanism of emergency contraception, during the peri-implantation period the effect of single and low dose of Mifepristone on the expression of integrin level in endometrium of healthy women were observed Materials ＆ Methods Eleven healthy women, proven fertility, were randomly divided into two groups: group LH-2 (n = 5) and LH+ 2 (n = 6). During the control and treatment cycle, placebo or 10 mg Mifepristone were given orally to group LH- 2 on cycle day LH- 2 or to group LH + 2 on cycle day LH - 2, respectively. One endometrial tissue specimen was obtained in both the control and the treatment cycle on cycle day LH+ 7.In this study, the endometrial specimens were assessed by immunohistochemistry analysis to measure the change of integrin α1, α4 and β3 subunits expression on the endometrium after using Mifepristone.Results Mifepristone increased the expression of α1 and α4 subunit in glandular epithelium only in group LH- 2. The expression of β3 integrin subunit remain the same in our experiments.Conclusion Treatment with Mifepristone interferes with integrin distribution during the implantation period, which may imply that the contraceptive effect of Mi fepristone is primarily due to impaired endometrial receptivity.

Laboratory Models for the Study of the Peri-implantation Period

The greatest risks to mammalian pregnancy occur during the peri-implantation period (passage through the uterotubal junction, blastulation, zona shedding, embryonic signaling and recognition, blastocyst attachment, postattachment events initiating placentation). Conventional markers and screening methods do not provide the means to clarify the relationship between exposure of a reproductively competent woman to a xenobiotic compound and the specific error in the functional expression of an embryogenetic process identified by impairment or deletion of that process. Laboratory models which provide the flexibility of in vitro culture methods and allow integration of cellular and molecular techniques have identified cell-specific, stage-specific markers that could focus on the mechanism of xenobiotic action. In vitro models have been used to define postattachment trophoblast cell differentiation. Trophoblast specific peptide hormones prove to be valid markers of established pregnancy. They provide no assessment of the risk to the embryo during the peri-implantation period. The relationship between developmental time of exposure and risk is discussed in terms of trophoblast differentiation.

Histopathological and Immunohistochemical Study of Peri-Implant Epithelium

Background: Human beta-defensins (HBDs), epithelial-derived antimicrobial peptides, contribute to gingival health and periodontal disease. Particularly, the upregulation of HBD-3 expression in periodontal tissues is described to contribute to periodontal tissue regeneration. Specifically, the upregulation of HBD-3 expression in periodontal tissues is described to contribute to periodontal tissue regeneration. But there has been insufficient investigation of the inner epithelium in peri-implantitis, especially the HBD expression patterns as protection against oral infection. Objectives: The purpose of this study was to investigate the histopathological characteristics of the inner implant epithelium in peri-implantitis using histopathological and immunohistochemical methods and to compare it with the inner marginal epithelium in periodontitis. Materials and Methods: The biopsied cases consisted of 10 peri-implantitis, 11 periodontitis, and 10 controls. HE observation, measurement of the thickness of the inner epithelium, and immunohistochemical analysis for Ki-67 and HBD-3 were conducted. Results: Concerning the thickness of the inner epithelium, it was significantly higher in periodontitis (156.2 [138.0, 186.4] μm) than in peri-implantitis and control, 70.7 [67.5, 97.5] μm and 80.7 [76.6, 89.4] μm, respectively (p Conclusion: Decreased production of HBD-3 in keratinocytes composing the inner implant epithelium may be one of the factors affecting tissue repair in peri-implantitis.

Investigation of Bacteria Species Most Involved in Peri-Implantitis

Purpose: Currently, bacteriological examinations of implant treatments target periodontopathic bacteria such as red complex bacteria, including Porphyromonas gingivalis, and detect them qualitatively or quantitatively. However, it seems that those examinations do not reflect the peri-implant tissue conditions precisely, because periodontopathic bacteria are also frequently detected from healthy peri-implant sites. The purpose of the present study was to investigate bacteria species most involved in peri-implantitis using a PCR method. Methods: Polymerase chain reaction (PCR) primers in this study were designed based on partial sequences of 16S rDNA of bacteria species involved in peri-implantitis that were described in numerous previous studies. Peri-implant sulcus fluid (PISF) samples were collected from thirty periodontally healthy patients with implants (HI) and thirty patients with peri-implantitis (PI). Each detection frequency of bacteria species in PISFs of both groups was investigated using a PCR method, and was compared using Fisher’s exact test. Results: In PI group, detection frequencies of Corynebacterium durum, Fretibacterium fastidiosum and Slackia exigua were significantly higher than those of HI group (p P. gingivalis and Tannerella forsythia belonging to red complex were frequently detected in the PISF samples of HI group (p > 0.05). Conclusion: It was suggested that monitoring C. durum and F. fastidiosum levels in PISF samples was useful as a clinical indicator for the evaluation of peri-implant tissue conditions.

Comparative Cytological and Histopathological Study of Peri-Implantitis and Periodontitis

Peri-implant diseases, such as peri-implant mucositis and peri-implantitis, pose significant challenges to the long-term prognosis of dental implants. This study aimed to comprehensively compare peri-implantitis with periodontitis from cytological and histopathological perspectives, shedding light on the morphological characteristics associated with peri-implantitis. Thirteen patients, including six with peri-implantitis and seven with periodontitis, were included in the study. Cytological examination of affected gingival mucosa revealed distinct differences between the two conditions. Peri-implantitis exhibited an inflammatory background predominantly composed of neutrophils with lobulated nuclei, accompanied by stratified squamous epithelial cells showing signs of keratinization. In contrast, periodontitis showed a similar neutrophilic inflammatory background but with non-keratinized epithelial cells. Histopathological examination further confirmed these differences, with peri-implantitis showing keratinized epithelium in the inner epithelial layer. This histological finding aligns with the notion that peri-implantitis has a distinct mucosal profile compared to periodontitis. Additionally, cytological analysis revealed that peri-implantitis had a lower occurrence rate of Light green-positive cells, indicating a tendency toward keratinization. This finding suggests that the presence of keratinized mucosa might be associated with peri-implant health, although further research is needed to clarify this relationship. Overall, this study demonstrates the potential of cytological examination and Papanicolaou staining for assessing mucosal inflammatory conditions and distinguishing between keratinized and non-keratinized cells. These findings underscore the utility of oral mucosal smears as a valuable tool for diagnosing peri-implantitis and enhancing our understanding of its pathogenesis.

In vitro antimicrobial effects of grape seed extract on peri-implantitis microflora in craniofacial implants

Objective:To determine the antimicrobial effects of grape seed on peri-implantitis microflora.Methods:The grape seed extract was tested against peri-implantitis microflora most commonly found in craniofacial implants including reference strains of Staphylococcus aureus(S.aureus),Escherichia coli(E.coli),Candida albicans(C.albicans)and clinical strains of S.aureus,Klebsiella pneumonia(K.pneumonia)and Candida parapsilosis(C.parapsilosis)by disk diffusion test.Minimum inhibitory concentrations(MIC)and minimum cidal concentrations(MCC)were determined using modified agar dilution millpore method.The extract was further combined with polyethylene glycol and propylene glycol,and was tested for antimicrobial effects.Results:Grape seed extract showed positive inhibitory effects with S.aureus at MIC of 0.625 mg/mL and MCC of1.25 mg/mL respectively.However the extracts showed minimal or no reactivity against strains of E.coli,K.pneumonia,C.parapsilosis and C.albicans.The use of grape seed extract in combination with polyethylene glycol and propylene glycol also showed dose dependent inhibitory effect on S.aureus.Conclusions:The results of the study showed that grape seed has potential antimicrobial effects which can be further studied and developed to be used in the treatment of infected skinabutment interface of craniofacial implants.

Expression of cellular fibronectin mRNA in adult periodontitis and peri-implantitis: a real-time polymerase chain reaction study

Cellular fibronectin （cFn） is a type of bioactive non-collagen glycoprotein regarded as the main substance used to maintain periodontal attachment. The content of cFn in some specific sites can reflect the progress of periodontitis or peri-implantitis. This study aims to evaluate the expression of cFn messenger RNA （mRNA） in tissues of adult periodontitis and peri-implantitis by real-time fluorescent quantitative polymerase chain reaction （PCR） and to determine its clinical significance. A total of 30 patients were divided into three groups of 10： healthy, adult periodontitis and peri-implantitis. Periodontal tissue biopsies （1 mmx I mmx I mm） from each patient were frozen in liquid nitrogen. Total RNA was extracted from these tissues, and the content, purity and integrity were detected. Specific primers were designed according to the sequence, and the mRNA expression levels of cellular fibronectin were detected by real-time PCR. The purity and integrity of the extracted total RNA were both high, and the specificity of amplified genes was very high with no other pollution. The mRNA expression of cFn in the adult periodontitis group （1.526＋0.441） was lower than that in the healthy group （3.253＋0.736）. However, the mRNA expression of cFn in the peri-implantitis group （3.965＋0.537） was significantly higher than that in the healthy group. The difference revealed that although both processes were destructive inflammatory reactions in the periodontium, the pathomechanisms were different and the variation started from the transcription level of the cFn gene.

Peri-implantitis and periodontitis: Use of bacteriological test in dental practice

Peri-implantitis has been defined as an inflamematory condition involving dental implants, surrounding mucosa and bone, which lose supporting bone. Although high success rates for endosseous implants have been reported, failures occur, and some implants are lost or removed. At least 10% of the failures have been suggested to be the result of peri-implantitis. One of the major causes of the peri-implantitis is the bacterial colonization of implant surfaces but additional risk factors such as periodontitis, poor oral hygiene, tobacco consumption, prepost operative therapies and genetic susceptibility should be considered. In the present study a real-time PCR bases assay was designed to detect and quantify red complex species, then used to investigate 307 periodontal pocket samples from 127 periodontitis patients and 180 controls. Results demonstrated a significant higher prevalence of red complex species and increased amount of Porphyromonas gingivalis and Treponema denticolain periodontal pocket of periodontitis. Since a higher risk of peri-implantitis occurs in periodontally affected patients, detection and treatment of bacteria is a fundamental objective to ensure dental implant survival.

Investigation of Peri-implant Status and Risk Variables for Implant Failure in Body of Maxilla after Oral Tumor Surgery

The aim of this study was to assess the peri-implant parameters and evaluate the clinical status with the survival of dental implants in body of maxilla after treatments of oral tumor. A follow-up examination included 27 patients who underwent the ablative tumor and （or） reconstructive surgery during a 5-year period. The follow-up protocol included clinical examination, radiological evaluation, and an interview using a standardized questionnaire. The reasons related to implant failure were studied by comparing the amount of failure with the value of marginal bone resorption, probing pocket depth, and plaque index using statistical t-test. The relationship between smoking and implant failure was analyzed statistically by chi-square test. The results showed among the 112 implants observed after implant loading, 29 have failed with the failure rate being 22.14 %. There was no significant correlation between the peri-implant status and the implant failure （P〉0.05）, however, the association of smoking and implant failure was statistically tested （P〈0.05）. It was suggested that the association of peri-implant status and implant failure in the maxilla after tumor surgery can＇t be statistically tested, however smoking was still a mainly significant factor.

Effect of tea polyphenols combined with photodynamic therapy on the efficacy and RANKL and Shh levels in patients with early peri-implantitis

Objective: To analyze the effect of tea polyphenols combined with photodynamic therapy on the efficacy and RANKL and Shh levels in patients with early peri-implantitis. Methods:Eighty patients with early peri-implantitis admitted to our hospital from January 2017 to December 2018 were randomly divided into the observation group and the control group;the control group was treated with photodynamic therapy, and the observation group was treated with tea polyphenols combined with photodynamic therapy. The levels of mPLI, PPD, mSBI and BOP were measured before treatment and 3 months after the treatment, and the levels of CRP, TNF-α, IL-6, RANKL and Shh in the gingival crevicular fluid were measured. Results:The levels of mPLI, PPD, mSBI and BOP in the observation group were significantly lower than those in the control group, and the difference was statistically significant (P<0.05). The levels of CRP, TNF-α, IL-6, RANKL and Shh in the gingival crevicular fluid were observed in the observation group. The differences were significantly lower than the control group, and the difference was statistically significant (P<0.05). Conclusions: The combination of tea polyphenols and photodynamic therapy for patients with early peri-implantitis can significantly improve clinical efficacy and reduce the inflammatory response, and can effectively improve the levels of RANKL and Shh in gingival crevicular fluid.

Health Indicator Bacteria That Is Useful for Risk Assessment of Peri-Implantitis

We established a novel identification method for oral Rothia species using one-step multiplex PCR analysis to investigate whether the monitoring of oral Rothia species levels is useful for peri-implantitis risk assessment, and to examine the oxygen concentration that these organisms need for growth in vitro. The mean number and proportion of Rothia aeria in peri-implant sulcus fluid (PISF) samples was significantly higher in the healthy implant group than in the peri-implantitis group (P < 0.05). Moreover, R. aeria under aerobic conditions vigorously grew compared with those under anaerobic conditions, and this organism grew only at the upper layer where high oxygen concentrations existed in a semi-liquid nutrient medium. Therefore, the monitoring of R. aeria levels may be suitable as an indicator of healthy peri-implant tissue conditions for the prevention of peri-implantitis.

Study on matrix metalloproteinase-2, 9 in peri-implant sulcular fluid

Objective: To study the expression of matrix metalloproteinases-2, 9 (MMP-2, MMP-9) of healthy implant and peri-implant sulcular fluid (PISF) by enzyme-linked immunosorbent assay (ELISA) method, and evaluate the level of MMP-2 and MMP-9 in sulcular fluid as an objective indicator of tissue inflammation around implants. Methods: A total of 40 implants were selected from 30 patients who were treated with dental implants and were divided into two groups: the inflammatory group and the healthy control group with 20 pieces respectively. ELISA double antibody sandwich method was used to detect the levels of MMP-2 and MMP-9 in PISF. Results: The MMP-2 and MMP-9 expressions were significantly different between the healthy implant group and the peri-implant group (p < .05). The concentration of MMP-2, MMP-9, and the amount of sulcular fluid in the inflammatory implant group were positively correlated with the clinical parameters (probing depth [PD], modified sulcus bleeding index [mSBI]). Conclusions: Under physiological conditions, the levels of MMP-2 and MMP-9 were low. When the periodontal tissue was stimulated by inflammation, the expression levels of MMP-2 and MMP-9 were increased, which could reflect the severity of inflammation. The increase levels of MMP-2 and MMP-9 in PISF could better reflect the health status of peri-implant tissues, which could be used as an objective indicator to assist in the diagnosis of peri-implant inflammation.

Dental Implant Patients Grouped by the Brinkman Index: Their Attitude toward Smoking, Nicotine Dependence, and Knowledge of Peri-Implantitis

Purpose: This study investigated the attitude of patients, grouped by the Brinkman index, towards smoking by using the Kano Test for Social Nicotine Dependence (KTSND) and their knowledge of peri-implantitis. Methods: The participants were 3093 new patients who visited the Tokyo Medical and Dental University Hospital from January 2012 to December 2013 for an oral implant. The methodology included a questionnaire about sex, age, smoking status, daily average number of cigarettes, years of smoking, knowledge of peri-implantitis, and the KTSND. The patients were grouped according to their smoking status by calculating their Brinkman index (over 200 or not): current smokers with the possibility of nicotine dependence (BI(+)CS), current smokers with no possibility of nicotine dependence (BI(-)CS), ex-smokers (ES), and non-smokers (NS). The Brinkman index is obtained by multiplying one’s daily average number of cigarettes by the number of years they have been smoking. Results: Data were collected from 2182 respondents (response rate = 71%). The KTSND scores of BI(+)CS (16.89 ± 4.26) were significantly higher than the scores of ES (11.99 ± 4.52) and NS (11.53 ± 5.01). In current smokers, there were no significant differences between BI(+)CS and BI(-)CS. The patients replied “I don’t know” about peri-implantitis most often in all groups;however, there were no significant differences between the groups. Discussion: BI(+)CS were more dependent on nicotine in social situations than the other groups were. In Japan, a Brinkman index over 200 is required for a nicotine-dependence management fee to be instituted for health insurance treatment. This is a major concern for young smokers, who may be excluded from treatment because their years of smoking are substantially less. Results revealed that there were no significant differences between BI(+)CS and BI(-)CS. Therefore, it was suggested that the Brinkman index did not sufficiently group the participants.

Platelet-rich plasma for regeneration of neural feedback pathways around dental implants: a concise review and outlook on future possibilities

Along with the development of new materials, advanced medical imaging and surgical techniques, osseointegrated dental implants are considered a successful and constantly evolving treatment modality for the replacement of missing teeth in patients with complete or partial edentulism. The importance of restoring the peripheral neural feedback pathway and thus repairing the lack of periodontal rnechanoreceptors after tooth extraction has been highlighted in the literature. Nevertheless, regenerating the nerve fibers and reconstructing the neural feedback pathways around osseointegrated implants remain a challenge. Recent studies have provided evidence that platelet-rich plasma （PRP） therapy is a promising treatment for musculoskeletal injuries. Because of its high biological safety, convenience and usability, PRP therapy has gradually gained popularity in the clinical field Although much remains to be learned, the growth factors from PRP might play key roles in peripheral nerve repair mechanisms. This review presents known growth factors contributing to the biological efficacy of PRP and illustrates basic and （pre-）clinical evidence regarding the use of PRP and its relevant products in peripheral nerve regeneration. In addition, the potential of local application of PRP for structural and functional recovery of iniured peripheral nerves around dental implants is discussed.

The effect of platform switching on the levels of metal ion release from different implant–abutment couples

The improved peri-implant bone response demonstrated by platform switching may be the result of reduced amounts of metal ions released to the surrounding tissues. The aim of this study was to compare the levels of metal ions released from platform-matched and platform-switched implant-abutment couples as a result of accelerated corrosion. Thirty-six titanium alloy （Ti-6AI-4V） and cobalt-chrome alloy abutments were coupled with titanium cylinders forming either platform-switched or platform-matched groups （n = 6）. In addition, 18 unconnected samples served as controls. The specimens were subjected to accelerated corrosion by static immersion in 1% lactic acid for 1 week. The amount of metal ions ion of each test tube was measured using inductively coupled plasma mass spectrometry. Scanning electron microscope （SEM） images and energy dispersive spectroscopy X-ray analyses were performed pre- and post-immersion to assess corrosion at the interface. The platform-matched groups demonstrated higher ion release for vanadium, aluminium, cobalt, chrome, and molybdenum compared with the platform-switched groups （P〈 0.05）. Titanium was the highest element to be released regardless of abutment size or connection （P〈0.05）. SEM images showed pitting corrosion prominent on the outer borders of the implant and abutment platform surfaces. In conclusion, implant-abutment couples underwent an active corrosion process resulting in metal ions release into the surrounding environment. The highest amount of metal ions released was recorded for the platform-matched groups, suggesting that platform-switching concept has a positive effect in reducing the levels of metal ion release from the implant-abutment couples.

Marginal bone loss around non-submerged implants is associated with salivary microbiome during bone healing

Marginal bone loss during bone healing exists around non-submerged dental implants. The aim of this study was to identify the relationship between different degrees of marginal bone loss during bone healing and the salivary microbiome. One hundred patients were recruited, and marginal bone loss around their implants was measured using cone beam computed tomography during a 3-month healing period. The patients were divided into three groups according to the severity of marginal bone loss.Saliva samples were collected from all subjected and were analysed using 16 SMiSeq sequencing. Although the overall structure of the microbial community was not dramatically altered, the relative abundance of several taxonomic groups noticeably changed. The abundance of species in the phyla Spirochaeta and Synergistetes increased significantly as the bone loss became more severe. Species within the genus Treponema also exhibited increased abundance, whereas Veillonella, Haemophilus and Leptotrichia exhibited reduced abundances, in groups with more bone loss. Porphyromonasgingivalis, Treponemadenticola and Streptococcus intermedius were significantly more abundant in the moderate group and/or severe group. The severity of marginal bone loss around the non-submerged implant was associated with dissimilar taxonomic compositions. An increased severity of marginal bone loss was related to increased proportions of periodontal pathogenic species. These data suggest a potential role of microbes in the progression of marginal bone loss during bone healing.

Potential Antimicrobial Effects of Gatifloxacin on Periodontopathic Bacteria in Vitro

The aim of this study was to identify the potential antibacterial effects of gatifloxacin on periodontal pathogens including Aggregatibacter actinomycetemcomitans, Porphyromonas gingi-valis, and Prevotella intermedia. The minimum inhibitory concentrations (MIC) of gatifloxacin and its bactericidal effects were investigated. Gatifloxacin inhibited the growth of all three kinds of periodontopathic bacteria tested in broth. The MIC value of 2.5 nM was found to be the most effective in inhibiting A. actinomycetemcomitans. An adenosine triphosphate biolumi-nescence assay revealed that gatifloxacin exhibited bactericidal effects on the tested bacteria in a time-dependent manner. The safety of gatifloxacin in mammalian cells was evaluated by assessing the viability of normal human dermal fibroblast (NHDF) cells treated with gatifloxacin. Almost all NHDF cells survived after 2-d culture, while 81% of the cells survived after 4-d culture when treated with 1.0 × 103 nM gatifloxacin. These results indicate that gatifloxacin is a possible drug for local administration to prevent periodontal infection.

Subtrochanteric fractures after retrograde femoral nailing

Secondary fractures around femoral nails placed for the management of hip fractures are well known. We report, two cases of a fracture of the femur at the interlocking screw site in the subtrochanteric area after retrograde femoral nailing of a femoral shaft fracture. Only a few reports in the existing literature have described these fractures. Two young men after sustaining a fall presented to us with pain, swelling and deformity in the upper thigh region. On enquiring, examining and radiographing them, peri-implant fractures of subtrochanteric nature through the distal interlocking screws were revealed in both patients who also had histories of previous falls for which retrograde intramedullary nailing was performed for their respective femora. Both patients were managed with similar surgical routines including removal of the existing hardware, open reduction and ace cephallomedullary antegrade nailing. The second case did show evidence of delayed healing and was additionally stabilized with cerclage wires. Both patients had uneventful postoperative outcomes and union was evident at the end of 6 mo postoperatively with a good range of motion at the hip and knee. Our report suggests that though seldom reported, peri-implant fractures around the subtrochanteric region can occur and pose a challenge to the treating orthopaedic surgeon. We suggest these be managed, after initial stabilization and resuscitation, by implant removal, open reduction and interlocking intramedullary antegrade nailing. Good results and progression to union can be expected in these patients by adhering to basic principles of osteosynthesis.

Preventing Implant Bacterial Infections with Interconnected 3D Porous Structures (I3D)— A Proof-of-Concept Study

Oral antibiotics are often prescribed to prevent infection after implant surgery;however, only a small fraction of the antibiotics can reach the implants. Thus, there are concerns about overusing antibiotics. We designed and fabricated porous implants with interconnecting 3D structures (I3D) and hypothesized that such I3D structures could serve as a depository for antimicrobial agents to prevent infection locally. The implants were either treated with antibiotics or coated with silver nanoparticles (AgNPs) by electrodeposition to test this hypothesis. The antimicrobial assay was conducted, and bacterial growth zones of inhibition (ZOIs) were monitored. Overall, I3D implants resulted in larger ZOIs than did the solid implants, and the center I3D (cI3D)-implant produced the largest ZOI. In the antibiotic treatment testing, the diameters of ZOIs of the solid implant vs. I3D implant were about 14 mm vs. 15 to 18 mm on day 2;however, the diameter quickly reduced to 9 mm on day 3 and 5 mm on days 6 and 8 for the solid implant, while no obvious change of the zone was seen for I3D implants. For the AgNPs coated implants, the ZOIs for the I3D implants were generally greater than the solid implant over four weeks of incubation. A significantly larger ZOI (~1 - 2 mm larger on average) was seen for AgNPs coated I3D implants at 0.1 V - 0.01 M, 0.3 V - 0.01 M, and 1.5 V - 0.01 M treatments compared to AgNPs coated solid implants. Given that we have previously shown that I3D implants can reserve chemoattractants to recruit stem cells to enhance osseointegration, we conclude that implants with the I3D structures could be beneficial not only for osseointegration but also in preventing infection.

Ca (II)-EDTA shows antimicrobial activity against periodontopathic bacteria

Ethylenediamine-N,N,N’,N’-tetraacetic acid calcium (II) disodium salt (Ca (II)-EDTA) was investigated for its antibacterial activity against the periodontal pathogens Aggregatibacter actinomycetemcomitans, Prevotella intermedia and Porphyromonas gingivalis. We determined the minimum inhibitory concentrations (MIC) of Ca (II)-EDTA and its bactericidal activity. Ethylenediamine-N,N,N’,N’-tetraacetic acid calcium (II) disodium salt inhibited the growth of all the periodontopathic bacteria tested in broth. An MIC of 60 mM was the most effective against P. gingivalis. An adenosine triphosphate bioluminescence assay revealed that Ca (II)-EDTA showed bactericidal activity against the bacteria tested in a time-dependent manner. To determine its safety in mammalian cells, we investigated the viability of murine L929 cells subjected to Ca (II)-EDTA treatment. At 75 mM, 93% ± 0.13% of the cells survived. These results indicate that Ca (II)-EDTA is a candidate chelating agent for prevention of infection by periodontopathic bacteria.