A multicenter prospective cohort study on the effect of smoking cessation on periodontal therapies in Japan

Few prospective studies have reported the effects of periodontal therapy on patients who attempted to quit smoking. This study aimed to assess how smoking cessation affects periodontal therapy. Twenty-five smokers with periodontitis were investigated by dividing them into two groups, a smoking cessation support group and a continued smoking group. Those in the support group received counseling and nicotine replacement therapy, followed by periodontal treatment conducted by dentists who had completed an e-learning course on smoking cessation. Clinical parameters were measured at baseline, 3, and 6 months. Most clinical parameters improved for those in the smoking cessation support group. There were no significant improvements in bleeding on probing (BOP) or the number of severe periodontal disease sites in the continued smoking group. Probing pocket depth (PPD) and clinical attachment levels (CAL) at sites that received scaling and root planing (SRP) significantly improved in all subjects. BOP did not improve at reevaluation in the smoking relapse subgroup. Patients in the smoking cessation support program led by dental professionals showed more improvement in BOP than those in the continued smoking group.

Dental implant care and trouble among dependent patients based on the questionnaire survey among Japanese dental practitioners

Background

Self-care and professional care of implants may prove difficult for elderly people who require nursing care. However, the actual state of care and problems remains unknown. In this study, we investigated the actual state of implant problems in elderly people living in their own home or in a nursing home who received visiting dental treatment.

Methods

We mailed questionnaire survey forms to 2339 representatives or specialists who were members of the Japanese Society of Oral Implantology, the Japanese Society of Gerodontology or the Japan Prosthodontic Society. We narrowed down the respondents to those who provided visiting dental treatment, and analyzed the actual state of implants observed during visiting dental treatment (type, care, problems, countermeasures, etc.).

Results

Of the 924 dentists who responded to the questionnaire survey, 291 (22%) provided visiting dental treatment. While the majority of implant types encountered in the previous 12 months were root-form implants, there were still a certain number of blade and subperiosteal implants. Daily implant care involved mostly cleaning with a toothbrush + auxiliary tools. The most frequent implant problems encountered in the past were difficulty in cleaning and peri-implantitis. Medication and antiphlogistic treatment were most frequently adopted as countermeasures to implant problems, followed by observation. When we classified the results into those for the dentists who provided implant treatment and those for the dentists who did not, we found that many of the dentists who did not provide implant treatment opted for observation or medication, while those who provided implant treatment also implemented removal of superstructure, retightening of screws, repair and so forth.

Conclusions

We found that many of the implant troubles encountered by dentists who provided visiting dental care were difficulty in cleaning or peri-implantitis, and that the actions taken against these troubles varied depending on the experience of the dentist performing the implant treatment. Our study also revealed that dentists who provide visiting dental care need to acquire knowledge and skills of implant treatment, to have actions prepared in case they encounter such cases, or to closely coordinate with dentists who specialize in implants.

The effects of intensive oral care before surgery for gastric cancer patients

OBJECTIVES

Oral function management has been recognized as important strategy for preventing postoperative complications. In this historical cohort study, we focused on the patients who planed gastrectomy, and investigated the appropriate duration and frequency of preoperative oral care to prevent complications after surgery.

METHODS

Patients who planed surgery for gastric cancer between 2012 and 2018 were enrolled. We defined intensive oral care (IOC) as initial intervention at least three weeks before surgery and follow-up intervention within a week before surgery. As the primary outcome, the incidence of postoperative infectious complications was compared between the IOC and non-intensive oral care groups.

RESULTS

A total of 576 patients were enrolled, including 66 with IOC. The incidence of infectious complications was 2/66 (3.0%) in the IOC group and 64/510 (12.5%) in the non-intensive oral care group. After adjusting for confounding factors, patients with IOC exposure had a lower chance of developing postoperative infectious complications (odds ratio; 0.217, 0.051-0.927).

CONCLUSIONS

Intensive oral care can help prevent postoperative infectious complications after gastrectomy. These findings suggest that appropriate preoperative oral care includes at least two interventions: three weeks or more before and within one week before surgery.

Oral infectious bacteria in dental plaque and saliva as risk factors in patients with esophageal cancer

BACKGROUND

High levels of periodontopathic bacteria as well as Streptococcus anginosus were detected in cancer tissue from patients with esophageal cancer. An association between oral infectious bacteria and esophageal cancer has been reported.

METHODS

Characteristics of the oral microbiota and periodontal conditions were studied as clinicopathologic factors in patients with esophageal cancer. The study included 61 patients with esophageal cancer and 62 matched individuals without any cancers. Samples of subgingival dental plaque and unstimulated saliva were collected to evaluate the prevalence and abundance of the following oral bacteria using a real-time polymerase chain reaction assay: Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Treponema denticola, and S. anginosus.

RESULTS

In the cancer group, the prevalence of all bacteria, with the exception of F. nucleatum, in dental plaque; the prevalence of A. actinomycetemcomitans in saliva; the abundance of all bacteria, with the exception of F. nucleatum and P. intermedia, in dental plaque; and the abundance of A. actinomycetemcomitans and S. anginosus in saliva were significantly higher. Furthermore, a logistic regression analysis suggested that the prevalence of T. forsythia and S. anginosus in dental plaque and of A. actinomycetemcomitans in saliva, as well as a drinking habit, were associated with a high risk of esophageal cancer, with a high odds ratio.

CONCLUSIONS

The current findings have potential implications for the early diagnosis of esophageal cancer.

Clinical comparison of an electric-powered ionic toothbrush and a manual toothbrush in plaque reduction: A randomized clinical trial

OBJECTIVES

This study aimed to evaluate the plaque removal efficacy of a newly developed electric-powered ionic toothbrush vs. a manual toothbrush.

MATERIALS AND METHODS

Manual or electric-powered ionic toothbrushes were randomly assigned to 30 healthy volunteers divided into two groups (Phase I). After 2 min of brushing, all tooth surfaces were stained with a plaque staining solution, and blinded examiners performed scoring using the Rustogi Modification of the Navy Plaque Index. Plaque removal rate was calculated at the central incisors, first premolar and first molar, as representative teeth, in the maxilla and mandibula. One week following Phase I, the same examinations were repeated in all subjects using another toothbrush (Phase II), as a crossover design.

RESULTS

Electric ionic toothbrushes demonstrated a significantly higher plaque removal rate than manual toothbrushes in the premolar and molar areas (p < .05). However, in the central incisor area, no statistically significant difference was observed.

CONCLUSIONS

Compared with manual toothbrushes, electric-powered ionic ones were significantly efficient in removing plaque in the premolar and molar areas.

The effect of antimicrobial photodynamic therapy using yellow-green LED and rose bengal on Porphyromonas gingivalis

INTRODUCTION

This study aimed to investigate the effects of a new antimicrobial photodynamic therapy (aPDT) system using yellow-green light-emitting diode (YGL) and rose bengal (RB) on Porphyromonas gingivalis (Pg) in vitro.

MATERIALS AND METHODS

Pg suspension mixed with RB was irradiated with YGL (565 nm) or blue light-emitting diode (BL, 470 nm) at 428 mW/cm² in comparison with chlorhexidine (CHG) treatment. The cells were cultured anaerobically on agar plates, and the number of colony-forming units (CFU) was determined. The treated suspension was anaerobically incubated, and the cell density (OD_600nm) was monitored for 24 h. Also, the viability of treated human gingival fibroblast (HGF-1) was measured using WST-8 assay. Pg morphology was observed with a scanning electron microscope. The RNA integrity number of aPDT-treated Pg was determined and gene expressions were evaluated by quantitative real-time polymerase chain reaction.

RESULTS

RB + YGL (aPDT) demonstrated a significantly higher reduction of CFU, compared to RB + BL (aPDT) and CHG, furthermore the OD value rapidly decreased. Morphological changes of Pg with RB + YGL were more severe than with CHG. Although RB + YGL reduced HGF-1 viability, aPDT's impact was significantly lower than CHG's. With RB + YGL treatment, RIN values decreased; furthermore, gene expressions associated with DNA replication and cell division were remarkably decreased after 12 h.

CONCLUSION

The results of this study demonstrated that a novel aPDT system using RB + YGL may have potential as a new technical modality for bacterial elimination in periodontal therapy.

Association between circulating tumor necrosis factor receptors and oral bacterium in patients receiving hemodialysis: a cross-sectional study

BACKGROUND

High levels of tumor necrosis factor (TNF) receptors (TNFRs; TNFR1 and TNFR2), markers of inflammation, have been reported as significant predictors of mortality in hemodialysis patients. Porphyromonas gingivalis is a major pathogenic bacterium involved in periodontitis, which induces systemic inflammation. We investigated the association between the abundance of P. gingivalis in saliva and serum TNFR levels in hemodialysis patients.

METHODS

A cross-sectional study was conducted on 121 hemodialysis patients visiting a clinic in the Tokyo metropolitan area. Medical interviews and examinations, comprehensive dental examinations, bacterial examinations for P. gingivalis in saliva, and measurements of circulating TNFR levels were conducted. Multiple linear regression analysis was performed to evaluate the association between the number of P. gingivalis and circulating TNFR levels.

RESULTS

TNFR1 and TNFR2 were positively correlated with high-sensitivity C-reactive protein (hsCRP). Severe periodontitis was significantly associated with the number of P. gingivalis in saliva but not serum TNFR levels. The number of P. gingivalis was significantly associated with both TNFR1 and TNFR2 levels in sera after adjusting for age, sex, body mass index, smoking status, history of diabetes, prior cardiovascular disease events, serum levels of hsCRP and albumin, and severity of periodontitis [for TNFR1: coefficient 0.76, 95% confidence interval (CI) 0.14-1.37, p = 0.02; for TNFR2: coefficient 0.95, 95% CI 0.09-1.80, p = 0.03].

CONCLUSION

Circulating TNFR levels are associated with the number of P. gingivalis in saliva after adjusting for relevant clinical factors.

Detection of hepatocyte growth factor in oral rinses using water for possible periodontal diagnosis

The aim of this study is to analyze the relationship between Hepatocyte Growth Factor (HGF) levels in oral rinses using water and clinical parameters of periodontitis; and furthermore, to evaluate the potential of a prototype HGF immunochromatographic paper test strip (HGF-TS) for screening of periodontitis, in comparison with a commercially-available occult blood (hemoglobin) test strip (Hb-TS). Clinical periodontal parameters were recorded, and oral rinses were collected, from 125 subjects. Then, the presence of HGF, and hemoglobin (Hb), in each sample was detected using a prototype HGF-TS and an Hb-TS. In addition, the concentrations of HGF and Hb were also determined in each sample is necessary HGF concentrations in oral rinses showed significant correlations with clinical parameters of periodontitis. The positive rate and read value on HGF-TS showed significantly high values in cases of severe periodontitis compared to healthy subjects. Hb-TS showed generally higher positive rates than HGF-TS; however, it showed false positive results in healthy subjects. The concentration of HGF in oral rinses showed close association with the severity of periodontitis, suggesting that the prototype HGF-TS has potential for use in the diagnosis of periodontitis, although further refinement of the test strip is required to increase the sensitivity.

Phylogenetic diversity in fim and mfa gene clusters between Porphyromonas gingivalis and Porphyromonas gulae, as a potential cause of host specificity

Background

Periodontopathic bacteria Porphyromonas gingivalis in humans and Porphyromonas gulae in animals are phylogenetically close and commonly have FimA and Mfa1 fimbriae. However, little is known about how fimA and mfa1 are phylogenetically different between P. gingivalis and P. gulae. Here, we examined phylogenetic diversity in their fim and mfa gene clusters.

Methods

Twenty P. gulae strains were isolated from the periodontal pocket of 20 dogs. For their genomic information, along with 64 P. gingivalis and 11 P. gulae genomes, phylogenetic relationship between the genotypes of fimA and mfa1 was examined. Variability of amino acid sequences was examined in the three-dimensional structure of FimA. The distance between strains was calculated for fim and mfa genes.

Results

Some fimA genotypes in P. gulae were close to particular types in P. gingivalis. Two types of mfa1 were classified as 70-kDa and 53-kDa protein-coding mfa1. The variable amino acid positions were primarily at the outer part of FimA. The genes encoding the structural proteins and the main component were similarly distant from the reference strain in P. gingivalis, but not in P. gulae.

Conclusions

The differences in the gene clusters between P. gingivalis and P. gulae may result in their host specificity.

The periodontopathic bacteria in placenta, saliva and subgingival plaque of threatened preterm labor and preterm low birth weight cases: a longitudinal study in Japanese pregnant women

OBJECTIVES

This study determined the quantity of periodontopathic bacteria in saliva, subgingival plaque, and placenta on the threatened preterm labor (TPL) and preterm low birth weight (PLBW) subjects in order to identify specific periodontal pathogens with high association to adverse pregnancy outcomes.

METHODS

We used real-time PCR with TaqMan probe and ELISA to detect the amount of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, and Prevotella intermedia in subgingival plaque, saliva, and placenta tissue, in addition to serum IgG titers against these bacteria in 28 patients with TPL and 36 healthy pregnant women.

RESULTS

Thirteen of 64 births delivered PLBW infants. All 6 periodontopathic bacteria were detected in the placenta samples. The amount of F. nucleatum and detection frequency of T. denticola in placental samples was significantly higher in the TPL group than in the healthy group. Meanwhile, the age, anti-P. gingival IgG in serum, amount of P. gingivalis and T. forsythia in plaque samples, detection frequency of P. intermedia in saliva, and percentage of pocket probing depth ≥ 5 mm were higher in TPL-PLBW births than those in TPL-Healthy delivery (HD) group and/or in H-HD group. Ordinal logistic regression analysis revealed that the presence of F. nucleatum in placental tissues was significantly associated with TPL, while the maternal age was significantly associated with PLBW in TPL.

CONCLUSION

Our findings suggested all 6 bacteria may access the placenta. The increased presence of F. nucleatum in placenta might be related to TPL, while advanced maternal age might be associated with PLBW in TPL.

CLINICAL RELEVANCE

Periodontal therapy should be applied to reduce the deep periodontal pocket sites and the colonization of periodontal pathogens in high-risk population.

Enhanced new bone formation in canine maxilla by a graft of electrically polarized β-tricalcium phosphate

We succeeded in the electrical polarization of β-tricalcium phosphate (β-TCP) granules and performed an unprecedented attempt to implant them into maxillary bone defects in canines to confirm their ability to facilitate new bone formation. Two holes were drilled into each maxilla half of a canine and filled with electrically polarized and nonpolarized β-TCP granules (grouping assignment was decided randomly). The implanted specimens were dissected en bloc and used for microcomputed tomography (μCT) observations and histological analyses 4 and 8 weeks after the operation. New bone ingrowth in the bone hole progressed over time from the superficial layer of the cortex toward the inner cancellous bone. The percentage area of new bone in the bone hole, as measured by μCT in the sagittal plane, was significantly larger after 4 and 8 weeks, and that measured by H&E-stained specimens in the transverse plane after 4 weeks was significantly larger in the polarized group than in the nonpolarized group. In addition to the structural stability and chemical characteristics of the β-TCP granules, electrical stimulation bears influence not indirectly but directly on osteogenic and vessel cells, which might work cooperatively for the early initiation of the bone formation process.

The relationship between the anti-Porphyromonas gingivalis immunoglobulin G subclass antibody and small for gestational age delivery: a longitudinal study in pregnant Japanese women

BACKGROUND

Maternal serum IgG antibody against Porphyromonas gingivalis is an indicator of both periodontitis and adverse pregnancy outcomes. This study aims to evaluate the anti-P. gingivalis IgG and IgG subclasses1-4 in threatened preterm labour (TPL) patients and their association with small for gestational age (SGA).

METHODS

Serum, saliva and subgingival plaque samples were collected from 47 TPL patients compared with 48 healthy pregnant women. The amount of P. gingivalis was measured in saliva and plaque using real-time polymerase chain reaction. The serum anti-P. gingivalis IgG titre and anti-P. gingivalis subclasses IgG 1-4 concentration were measured using enzyme-linked immunosorbent assay.

RESULTS

The amount of anti-P. gingivalis IgG-1 was significantly lower in the TPL group than in the healthy group. Fourteen subjects delivered SGA infants in the TPL group. The pocket probing depth (PPD), clinical attachment loss, PPD ≥ 5 mm%, amount of P. gingivalis in plaque, anti-P. gingivalis IgG and anti-P. gingivalis IgG-4 were significantly higher in the TPL-SGA group than in the TPL-normal weight group. Moreover, logistic regression analysis revealed the detection frequency of P. gingivalis in plaque and placenta weight were significantly correlated with SGA in TPL. In the receiver operating characteristic curve analysis, an amount of P. gingivalis in plaque ≥ 86.45 copies showed a sensitivity of 0.786 and a specificity of 0.727 (AUC 0.792) for predicting SGA in TPL.

CONCLUSION

Lower anti-P. gingivalis IgG-1 amounts are related to TPL, while higher anti-P. gingivalis IgG and IgG-4 are related with SGA in TPL. Further, greater colonisation of P. gingivalis in plaque might increase the risk of SGA and can be useful in prediction of SGA in TPL.

Ex Vivo Evaluation of Gingival Ablation with Various Laser Systems and Electroscalpel

Objective: The aim of this study was to perform a systematic and multifaceted comparison of thermal effects during soft tissue ablation with various lasers and an electroscalpel (ES). Materials and methods: Er:YAG, Er,Cr:YSGG, CO₂, Diode, Nd:YAG lasers (1 W, pulsed or continuous wave), an ES, and a scalpel (Sc; control), were employed for porcine gingival tissue ablation. Temperature changes during ablation were measured by using an infrared thermal imaging camera and a thermocouple. After ablations, the wounds were observed using stereomicroscopy and scanning electron microscopy (SEM), and histological sections were analyzed. Compositional analysis was also performed on ablated sites by SEM wavelength dispersive X-ray spectroscopy. Results: The surface temperature during irradiation was highest with CO₂ (over 500°C), followed by Diode (267°C) and Nd:YAG (258°C), Er:YAG (164°C), ES (135°C), and Er,Cr:YSGG (85°C). Carbonization was negligible (Er:YAG), slight (Er,Cr:YSGG), moderate (Nd:YAG and ES), and severe (CO₂ and Diode). Under SEM observation, Er:YAG and Er,Cr:YSGG showed smooth surfaces but other devices resulted in rough appearances. Histologically, the coagulated and thermally affected layer was extremely minimal (38 μm in thickness) and free from epithelial collapse for Er:YAG. Compared with other devices, less compositional surface change was detected with Er:YAG and Er,Cr:YSGG; additionally, the use of water spray further minimized thermal influence. Conclusions: Among various power devices, Er:YAG laser showed the most efficient and refined gingival ablation with minimal thermal influence on the surrounding tissues. Er:YAG and Er,Cr:YSGG lasers with water spray could be considered as minimally invasive power devices for soft tissue surgery.

Salivary and serum interleukin-17A and interleukin-18 levels in patients with type 2 diabetes mellitus with and without periodontitis

OBJECTIVE

Interleukin (IL)-17A and IL-18 have been proposed to play important roles in periodontitis and type 2 diabetes mellitus (DM), but human data are conflicting. The present study aimed to investigate the roles of IL-17A and IL-18 in periodontitis and DM by measuring salivary and serum levels, respectively.

MATERIALS AND METHODS

A total of 49 participants with type 2 DM and 25 control subjects without type 2 DM were recruited. A periodontal screening and recording (PSR) index (0, 1-2, 3, and 4) was used to classify whether these subjects had periodontitis. Salivary and serum IL-17A and IL-18 levels were measured by enzyme-linked immunosorbent assay. Multiple linear regression analyses were used to evaluate the associations between these cytokines and clinical parameters.

RESULTS

Salivary IL-17A levels were not significantly different between patients with DM and controls, however, the levels were significantly higher in controls with periodontitis than those without periodontitis (p = 0.031). Salivary IL-17A levels were significantly associated with the PSR index (β = 0.369, p = 0.011). Multiple linear regression analyses revealed the association of salivary IL-18 levels and fasting plasma glucose (β = 0.270, p = 0.022) whereas serum IL-18 levels were associated with HbA1C (β = 0.293, p = 0.017). No correlation between salivary and serum levels of IL-17A and IL-18 was found.

CONCLUSION

Salivary IL-17A was strongly associated with periodontitis, whereas salivary IL-18 was associated with FPG and serum IL-18 was associated with HbA1C. These results suggest the role of these cytokines in periodontal inflammation and DM.

Ridge reconstruction in damaged extraction sockets using tunnel β-tricalcium phosphate blocks: A 6-month histological study in beagle dogs

OBJECTIVE

The present study aimed to evaluate the histological outcome of tunnel β-TCP blocks grafting in extraction sockets missing the buccal bone wall, after 6 months of healing.

BACKGROUND

Tunnel β-tricalcium phosphate (β-TCP) blocks made of randomly organized tunnel-shaped β-TCP ceramics appeared promising for alveolar ridge preservation in tooth extraction sockets missing the buccal bone, in a previous study in dogs, with a 2-month healing time.

METHODS

In six beagle dogs, the maxillary first premolars were extracted and the buccal bone was surgically removed to create bone defects of 4 mm (mesio-distal) × 5 mm (apico-coronal) × 4 mm (bucco-palatal). Thus, extraction sockets missing the buccal bone plate were grated with tunnel β-TCP blocks (test) or left empty for spontaneous healing (control). Histology/histomorphometry was performed after 6 months of healing.

RESULTS

The horizontal bucco-palatal width of the alveolar ridge was significantly greater at test sites than at control sites. The amount of mineralized tissue was greater at test sites (57.8% ± 11.1%) than at control sites (28.9% ± 8.5%), while the amount of connective tissue was significantly greater at control sites (41.7% ± 6.4%) than at test sites (19.6% ± 9.2%). No significant difference was found between sites in terms of basic multicellular units and bone marrow. Residual β-TCP at test sites was 5.8% ± 3.2%.

CONCLUSION

Grafting with tunnel β-TCP block significantly limited the resorption of the alveolar ridge at extraction sockets missing the buccal bone compared with sites left to heal spontaneously, even after 6-month follow-up.

Accuracy of cone beam computed tomography in evaluation of palatal mucosa thickness

AIM

The purpose of this study was to investigate the accuracy of the measurement of palatal mucosa thickness using cone beam computed tomography (CBCT) and to create a conversion formula to evaluate palatal mucosa thickness more accurately. We then evaluated the palatal mucosa thickness in a Japanese population using CBCT and the conversion formula.

MATERIALS AND METHODS

We evaluated palatal mucosa thickness in 10 healthy subjects at 15 sites using CBCT, digital impression, and K file. Multiple regression analysis was performed to create a conversion formula to measure thickness accurately. We then obtained CBCT data from 174 patients retrospectively, applied the conversion formula, and evaluated palatal mucosa thickness.

RESULTS

Sites of measurement affected measurement error. Measurement using CBCT was 0.34 ± 0.04 mm smaller than actual measurement; therefore, a conversion formula was created. Male, age ≥60 years, and probing pocket depth ≥4 mm had significant and positive associations with palatal mucosa thickness; however, no association was observed between bleeding on probing and palatal mucosa thickness.

CONCLUSION

CBCT is useful for the noninvasive and accurate measurement of palatal mucosa thickness.

The bacterial association with oral cavity and intra-abdominal abscess after gastrectomy

BACKGROUND

Perioperative oral management has been reported to be effective for preventing postoperative infectious complications. In addition, severe periodontal disease was identified as the significant risk factor for complications after gastrointestinal surgery. We investigated the bacteriological association between the periodontal pocket, stomach mucosa and drainage fluid to determine whether oral bacteria directly cause intra-abdominal infection after gastrectomy.

METHODS

Patients who were scheduled to undergo surgery for gastric cancer were prospectively enrolled. We evaluated the similarity of bacterial strains in periodontal pocket, stomach mucosa and fluid from drainage tube. Gingival crevicular fluid and dental plaque were collected from the periodontal pocket and cultured to detect bacteria. Specimens from the resected stomach were collected and used for bacterial culturing. Drainage fluid from the abdominal cavity was also cultured.

RESULTS

All of 52 patients were enrolled. In the periodontal pocket, α-Streptococcus spp., Neisseria sp., and Prevotella sp. were mainly detected. Bacterial cultures in the stomach mucosa were positive in 26 cases. In 20 cases (76.9%), the detected strains were the same as those in the periodontal pocket. Six patients had the postoperative intra-abdominal infection after gastrectomy, and the same bacterial strains was detected in both of drainage fluid and periodontal pocket in two patients with severe periodontal disease.

CONCLUSIONS

We found the bacteriological association that same strain detected in periodontal pocket, stomach and in intra-abdominal drainage fluid after gastrectomy in patients with periodontal disease.

P1363 Risk factors of severe tricuspid regurgitation after left-sided valve surgery

Background

Tricuspid regurgitation (TR) sometimes deteriorate late after left-sided valve surgery. The recent guidelines recommend tricuspid valve repair at the same time as the left-sided valve surgery. However, little is known about the pathophysiology that leads to severe TR after left-sided valve surgery.

Purpose

To clarify the risk factors of the patients with severe TR after left-sided valve surgery.

Methods

We retrospectively investigated consecutive 526 patients diagnosed as severe TR from January 2004 to December 2018 at our hospital. Clinical background, echocardiographic parameters were evaluated. Demographic information and clinical data (including age, electrocardiograms, type of left-sided valve surgery, underlying valve diseases and history of pacemaker or ICD implantation) were obtained by chart review.

Results

Of the 526 patients with severe TR, 107 patients were after a left-sided valve surgery. Patients developed severe TR at a mean of 14.8 ± 8 years after surgery.The surgical indications were as follows: mitral valve stenosis (74 patients, 69%), mitral valve regurgitation (43 patients, 40%), aortic valve stenosis (37 patients, 35%) and aortic regurgitation (28 patients, 26%), respectively. The mean age at diagnosis of severe TR was 74 ± 10 years and 75 were female (70%). Among those patients, 32 patients (30%) had a tricuspid annuloplasty (TAP) with the first left-sided valve surgery. Ninety-five patients (88%) had atrial fibrillation (AF), 75 patients (70%) were diagnosed as rheumatic heart disease, 64 patients (60%) had pulmonary artery hypertension (PH) and 28 patients (26%) had a permanent pacemaker or ICD implantation.

There were only 12 patients who had severe TR without AF. Eight of 12 patients without AF had PH, and permanent pacemakers were implanted in remaining 4 patients.

Conclusions

Almost all patients with severe TR after left-sided valve surgery present with AF and prevalence of rheumatic heart disease were about 70 percent. These two factors may be one of the important risk factors for severe TR after left-sided valve surgery.

Oral-bacterial-induced arterial and venous thrombus in rats: Pathological and immunological studies

Objectives

Our study investigated the pathological outcome of experimental thrombi that incorporate oral bacteria.

Material and methods

A small artery and vein in the rats' groins were injected with a solution containing periodontal bacteria Porphyromonas gingivalis and followed up for 28 days. In all, 18 limbs of nine male rats (500-650 g) were used for the arterial study, and eight limbs of four rats were used for the veins. Two densities of the bacterial solution and two arterial thicknesses sizes were used in the arterial study. Both proximal and distal arteries and veins were ligated loosely using a monofilament nylon suture before bacterial suspensions or control solutions were injected into the ligated vessels.

Results

After 7, 14-18, and 28 days, the rats were sacrificed. Pathology and immunohistochemistry were performed. All specimens exhibited thrombus formation and an acute inflammation reaction with granulocytes at 7 days and then settled down to chronic fibrous change with plasma cells or macrophages at 28 days in the arterial thrombus. CD3 (Pan T-cells), CD79a (Pan B cells in the rats), and IgG were observed in the process of the healing of the arterial thrombus. Venous changes showed relatively clear recanalization that appeared at 7 days, which is slightly different from the artery. Granulocytes were present from 7 to 28 days.

Conclusions

Periodontal bacteria act as an inflammatory core in the vessels, but not as an infectious agent, in our experiments, because of their low ability to invade tissues.

Japanese subgingival microbiota in health vs disease and their roles in predicted functions associated with periodontitis

The present study aimed to identify and compare the microbial signatures between periodontally healthy and periodontitis subjects using 454 sequences of 16S rRNA genes. Subgingival plaque samples were collected from ten periodontally healthy subjects and ten matched chronic periodontitis patients. Bacterial DNA was extracted and next-generation sequencing of 16S rRNA genes was performed. The microbial composition differed between healthy subjects and periodontitis patients at all phylogenetic levels. Particularly, 16 species, including Lautropia mirabilis and Neisseria subflava predominated in healthy subjects, whereas nine species, including Porphyromonas gingivalis and Filifactor alocis predominated in periodontitis. UniFrac, a principal coordinate and network analysis, confirmed distinct community profiles in healthy subjects and periodontitis patients. Using predicted function profiling, pathways involved in phenylpropanoid, GPI-anchor biosynthesis, and metabolism of alanine, arginine, aspartate, butanoate, cyanoamino acid, fatty acid, glutamate, methane, proline, and vitamin B6 were significantly over-represented in periodontitis patients. These results highlight the oral microbiota alterations in microbial composition in periodontitis and suggest the genes and metabolic pathways associated with health and periodontitis. Our findings help to further elucidate microbial composition and interactions in health and periodontitis.

Increased Heart Failure Prevalence in Patients with a High Antibody Level Against Periodontal Pathogen

The aim of this study was to assess whether a specific cardiovascular disease was related to an increased antibody level against a periodontal pathogen.A strong association between cardiovascular disease and periodontitis was shown, however, the causal relationship was not proven. Increased inflammatory reaction of patients with periodontitis was a possible factor, which connected periodontal infection and vascular diseases.We assessed medical history, blood data, and periodontal conditions in patients with cardiovascular diseases. Serum IgG antibody titers against major periodontal pathogens and existence of salivary periodontal bacteria were analyzed.In total, 348 subjects were enrolled in this study. The patients who exhibited 10,000 counts/mL or more of salivary Porphyromonas gingivalis were divided into two groups according to the antibody level of the pathogen. Patients with a high antibody level against Porphyromonas gingivalis exhibited a high rate of heart failure compared to the low antibody group. Mean probing pocket depth and clinical attachment level significantly increased in the high antibody group. We found that the high anti-Porphyromonas gingivalis antibody group also experienced enhanced antibody levels against other periodontal bacteria.An increased heart failure prevalence was found in patients with a high antibody level against a major periodontal pathogen, Porphyromonas gingivalis.

Analysis of factors related to needle-stick and sharps injuries at a dental specialty university hospital and possible prevention methods

Needle-stick and sharps injuries (NSIs) can happen even when dental health care workers (DHCWs) act in compliance with standard precautions to prevent transmitting blood-borne infections. The objective of this study was to investigate causes of NSIs that had occurred at a dental specialty university hospital during the past 12 academic years. A total of 215 NSIs were reported during the investigation period, and NSIs ascribed to female DHCWs (n = 148; 68.8%) were significantly (P < 0.05) more common than those ascribed to male DHCWs (n = 67; 31.2%). One hundred twenty-six NSIs (58.6%) were caused by DHCWs with little experience (P < 0.05), and 37 of those (17.2% of the total) were ascribed to undergraduate students during clinical training (P < 0.05). The NSIs occurred both during treatment (n = 119; 55.3%) and during cleaning up used devices (n = 89; 41.4%). The NSIs at the dental hospital occurred with a probability of 0.004% of total therapeutic opportunities. Prevention of NSIs should be the responsibility of dental students and DHCWs, and should be a part of education about infection control to prevent the nosocomial transmission of blood-borne pathogens.