Polymicrobial periodontal disease triggers a wide radius of effect and unique virome.

Periodontal disease is a microbially-mediated inflammatory disease of tooth-supporting tissues that leads to bone and tissue loss around teeth. Although bacterially-mediated mechanisms of alveolar bone destruction have been widely studied, the effects of a polymicrobial infection on the periodontal ligament and microbiome/virome have not been well explored. Therefore, the current investigation introduced a new mouse model of periodontal disease to examine the effects of a polymicrobial infection on periodontal ligament (PDL) properties, changes in bone loss, the host immune response, and the microbiome/virome using shotgun sequencing. Periodontal pathogens, namely Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Fusobacterium nucleatum were used as the polymicrobial oral inoculum in BALB/cByJ mice. The polymicrobial infection triggered significant alveolar bone loss, a heightened antibody response, an elevated cytokine immune response, a significant shift in viral diversity and virome composition, and a widening of the PDL space; the latter two findings have not been previously reported in periodontal disease models. Changes in the PDL space were present at sites far away from the site of insult, indicating that the polymicrobial radius of effect extends beyond the bone loss areas and site of initial infection and wider than previously appreciated. Associations were found between bone loss, specific viral and bacterial species, immune genes, and PDL space changes. These findings may have significant implications for the pathogenesis of periodontal disease and biomechanical properties of the periodontium. This new polymicrobial mouse model of periodontal disease in a common mouse strain is useful for evaluating the features of periodontal disease.

Herpes Simplex I virus impairs regenerative outcomes of periodontal regenerative therapy in intrabony defects: a pilot study.

AIM: To evaluate the impact of herpesvirus type-1 and -2 on the clinical outcomes of periodontal regenerative procedures in isolated deep intrabony pockets, in an experimental population with no detectable periodontal pathogens. MATERIALS AND METHODS: Seventeen periodontal intraosseous defects in 17 moderate-to-advanced periodontitis patients were treated with regenerative therapy and amelogenins. Microbiological evaluation was performed at baseline (after the completion of initial therapy) and at 1 year to exclude the presence of periodontal pathogens. Herpesviruses-1 and -2 DNA were quantified in the pocket tissues associated to the intrabony defect using molecular assays. Clinical attachment level (CAL), probing pocket depth (PPD) and gingival recession (REC) were recorded at baseline and at 1 year. RESULTS: After 1 year, the 17 defects resulted in significant CAL gain, PPD reduction and REC increase. HSV-1 was detected in five patients. Herpesvirus-2 was never found. The two subpopulations positive or negative to herpesvirus-1 were homogeneous at baseline. At 1 year, the five herpesvirus-1 positive patients resulted in lower amounts of CAL-gain and PPD reduction and greater amount of REC with respect to the 12 herpesvirus-1 negative patients. CONCLUSIONS: The presence of herpesvirus-1 at baseline is associated with poor clinical outcomes following regenerative therapy.

Prevalence of human cytomegalovirus and Epstein-Barr virus in subgingival plaque at peri-implantitis, mucositis and healthy sites. A pilot study.

This study evaluated the prevalence of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in peri-implantitis and mucositis sites and the correlation between herpesvirus and clinical parameters. Fifty-six dental implants (mean time of loading, 4.27±1.6 years) were evaluated (20 peri-implantitis, 18 mucositis, 18 healthy peri-implant sites.) The clinical parameters assessed were: visible plaque index (PI), bleeding on probing (BOP), suppuration (SUP), probing depth (PD). A polymerase chain reaction assay identified HCMV and EBV in subgingival plaque samples. The percent of sites with plaque and BOP was significantly higher around mucositis and peri-implantitis compared with healthy implants (p<0.05). The mean PD around the implants was significantly higher in peri-implantitis, followed by mucositis and healthy implants (p<0.05). HCMV was detected in 13 (65%) and EBV in 9 (45%) of the 20 peri-implantitis sites. HCMV was found in 1 of the 18 (6%) healthy periodontal sites and EBV in 2 (11%). A statistically significant correlation was found between presence of HCMV and EBV subgingivally and clinical parameters of peri-implantitis and healthy sites. These results confirm the high prevalence of HCMV and EBV in subgingival plaque of peri-implantitis sites and suggest the viruses have a possible active pathogenic role in peri-implantitis.

Low prevalence of subgingival viruses in periodontitis patients.

BACKGROUND: Viruses such as Human Cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) have been proposed to be periodontal pathogens. The aim of this study was to analyse the presence of herpesvirus DNA in subgingival plaque samples of patients with different forms of periodontitis and in healthy periodontia. MATERIALS AND METHODS: A total of 140 ethnically mixed (prevalently Caucasian) subjects took part in the study. Sixteen were affected by localized aggressive periodontitis (LAgP), 64 by generalized aggressive periodontitis (GAgP), 20 by chronic periodontitis (CP) and 40 were periodontally healthy. Polymerase chain reaction (PCR) analyses were performed to detect HCMV and EBV. Sera were tested for anti-HCMV and EBV IgG antibodies. PCRs for herpes simplex (HSV) and varicella zoster virus (VZV) were performed in subgingival samples from a subset of 20 AgP subjects. RESULTS: HCMV DNA was not detected in any plaque samples. EBV DNA was detected in four LAgP (25%), two GAgP (3%) subjects and four healthy individuals (10%). HSV DNA and VZV DNA were not detected in the subset of studied individuals. CONCLUSIONS: This study challenges the previously reported high prevalence of herpesvirus DNA in subgingival samples from periodontitis patients and so questions whether they act as pathogens in such patients.

Herpesviruses in abscesses and cellulitis of endodontic origin.

Acute apical abscesses and cellulitis are severe endodontic diseases caused by opportunistic bacteria with possible coinfection with latent herpesviruses. The objectives of this study are to identify herpesviruses, including human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), herpes simplex virus-1 (HSV-1), and Varicella zoster virus (VZV) in patients (n = 31) presenting with acute apical abscesses and cellulitis of endodontic origin. Primary and nested polymerase chain reaction (PCR) was conducted using virus-specific primers and DNA isolated from cell-free abscess fluid. From patients exhibiting concurrent spontaneous pain (n = 28), nine abscesses contained HCMV, two abscesses contained EBV, one abscess contained HSV-1, and no abscesses contained VZV. Control PCR using genomic or recombinant templates showed detection limits to a single genomic copy of HCMV, 100 genomic copies for EBV, and 1 to 10 copies for HSV-1 with no cross-amplification between herpesviral DNA targets. Nested PCR was required for detection of herpesviral DNA in the abscess specimens, indicating that these viruses were present in low copy number. Filtration of abscess specimens and virus transfer experiments using human fibroblastic MRC-5 cells confirmed the presence of HCMV particles in several abscess specimens. We conclude that herpesviruses are present but not required for the development of acute apical abscesses and cellulitis of endodontic origin.

Comparison of nested polymerase chain reaction (PCR), real-time PCR and viral culture for the detection of cytomegalovirus in subgingival samples.

INTRODUCTION: The purpose of this study was to compare nested polymerase chain reaction (PCR), real-time PCR, and shell vial for the detection of human cytomegalovirus (HCMV) in subgingival samples in periodontitis patients. METHODS: A group of 44 patients and 24 individuals without periodontitis were included in the study. A full periodontal examination was conducted in each subject. Gingival crevicular fluid (GCF) was collected by pocket lavage and used for viral culture (shell vial). Additional subgingival samples were obtained with paper points and used for molecular analysis. Nested PCR and real-time PCR were used to detect and quantify HCMV. Student's t-test and chi-squared test were used to compare groups. The sensitivity and specificity for the tests were calculated on 2 x 2 tables considering the nested PCR as the gold standard. RESULTS: The detection of HCMV was greater using nested PCR than with either real-time PCR or shell vial (P < 0.0001). However, the frequency detection of both molecular techniques was higher than in viral culture (P < 0.0001). Only one case of chronic periodontitis was positive by viral culture. Agreement between nested PCR and real-time PCR was observed 47.7% and 4.1% of the time in the periodontitis and control groups, respectively. The sensitivity of real-time PCR was 60%, compared with 2.8% for the shell vial technique. CONCLUSIONS: In conclusion, this study confirmed that active HCMV infection occurs in human periodontitis; however, its frequency seems to be low. In contrast, latent periodontal HCMV infection seems to be a more frequent event.

Alveolar bone necrosis and tooth exfoliation following herpes zoster infection: a review of the literature and case report.

BACKGROUND: Herpes zoster (HZ) presents as a cutaneous vesicular eruption in the area innervated by the affected sensory nerve, usually associated with severe pain. Oral manifestations of HZ appear when the mandibular or maxillary divisions of the trigeminal nerve are affected. METHODS: This is a case report of a 63-year-old woman with HZ infection with trigeminal nerve involvement that led to a rapid loss of alveolar bone and exfoliation of two teeth. RESULTS: The initial intraoral examination showed redness of the alveolar mucosa and gingiva of the lower right quadrant with multiple well-delimited and painful erosive lesions affecting the attached gingiva around the teeth. Two weeks later, teeth number 27 (lower right canine) and 28 (lower right first premolar) had class III mobility, flow of purulent exudate from the gingival sulcus, and deep pockets (>11 mm). The radiological examination showed advanced alveolar bone loss around both teeth. The prognosis for teeth number 27 and 28 was considered hopeless, and they were extracted. Due to extensive necrosis there was no interdental alveolar bone. The case is presented with a review of clinical data from patients with trigeminal HZ infection associated with osteonecrosis or exfoliation of teeth previously reported in the literature. The mechanisms by which the HZ infection leads to the alveolar bone necrosis are discussed. CONCLUSIONS: Extensive osteonecrosis and exfoliation of teeth in the area innervated by the nerve affected by HZ has been reported after HZ infection. Clinicians should be aware of this possible outcome after a trigeminal HZ infection.

Cytomegalovirus periodontal presence is associated with subgingival Dialister pneumosintes and alveolar bone loss.

Destructive periodontal disease is associated with human cytomegalovirus (HCMV), Epstein-Barr type 1 virus (EBV-1) and other members of the Herpesviridae family as well as with various gram-negative anaerobic bacteria, including the Dialister pneumosintes species. This study aimed to determine possible interrelationships between periodontal HCMV, EBV-1, herpes simplex virus and D. pneumosintes, and relate the microbiological findings to periodontitis clinical status. Sixteen subjects each contributed paper point samples from two progressing and two stable periodontitis lesions, as determined by ongoing loss of probing attachment. Polymerase chain reaction methodology was used to identify the study herpesviruses and D. pneumosintes. Chi-squared tests, Fisher exact tests and multivariate logistic regression were employed to identify statistical associations among herpesviruses, bacteria and clinical variables. HCMV, and no other virus or combination of viruses, was positively associated with the presence of D. pneumosintes, and the relationship was specific for individual periodontitis sites with no detectable subject effect. D. pneumosintes was in turn positively associated with periodontal pocket depth and disease-active periodontitis. When the average percentage of alveolar bone loss in all teeth was treated as a response, HCMV remained significant even after D. pneumosintes was included in the model, suggesting that both HCMV and D. pneumosintes affected bone loss or, alternatively, HCMV affected factors not studied that themselves can induce bone loss. We hypothesize that periodontal HCMV sets the stage for subgingival proliferation of D. pneumosintes and subsequent periodontal disease progression. Studies on herpesviral-bacterial interactions may hold great promise for delineating important etio-pathogenic aspects of destructive periodontal disease.

Clinical and microbiological evaluation of a bioabsorbable and a nonresorbable barrier membrane in the treatment of periodontal intraosseous lesions.

Clinical and microbiological features of periodontal healing in barrier membrane-treated sites were determined in a randomized clinical trial. The study included 10 patients with advanced adult periodontitis and a minimum of one set of similar 2 to 3 wall intraosseous periodontal lesions with no furcation involvement. In each patient, one periodontal lesion was treated with a biodegradable membrane and a contralateral lesion with a nonresorbable barrier membrane. Within the preceding 3 months of regenerative therapy, all patients received full mouth osseous surgery except for the sites for regeneration, were instructed in oral hygiene, and were prescribed systemic ciprofloxacin and metronidazole (250 mg of each, TID, 8 days), starting 7 days before membrane placement. At baseline and at 6 months postsurgery, probing depth and clinical attachment level were assessed in each study site. The subgingival presence of suspected periodontal pathogens was determined by non-selective and selective culture and by DNA probe analyses, and of human cytomegalovirus (HCMV) and Epstein-Barr virus type 1 (EBV-1) by a nested-polymerase chain reaction detection method. At baseline, the barrier-treated sites did not differ significantly in clinical and microbial parameters. Mean baseline probing depth was 7.8+/-1.1 mm for bioabsorbable and 7.9+/-1.3 mm for nonresorbable barrier-treated sites. At 6 months, sites treated with bioabsorbable barrier revealed 4.6+/-1.7 mm gain of clinical attachment (range: 1 to 7 mm) and sites treated with nonresorbable barrier 4.2+/-2.0 mm (range: 1 to 8 mm). The 11 barrier-treated sites that harbored 10% or less bacterial pathogens and were free of HCMV and EBV-1 averaged significantly more clinical attachment gain than the 9 sites that yielded more than 10% bacterial pathogens and/or test viruses (5.6 mm versus 3.0 mm; P=0.005). The present data suggest bioabsorbable and nonresorbable barriers provide similar clinical healing of 2 to 3 wall intraosseous periodontal lesions, emphasize the importance of controlling bacterial pathogens prior to and during periodontal healing, and point to the possible detrimental role of HCMV and EBV-1 in periodontal repair.

HIV-associated fulminating herpes zoster infection with alveolar necrosis and tooth exfoliation: a case report.

This paper presents a case of HIV-associated fulminating herpes zoster infection (HZI) that culminated in right mandibular necrosis and tooth exfoliation. The occurrence of such infection in immunosuppression and the impending clinical features are briefly reviewed and discussed.

Host defensive, immunological, and microbiological observations of an early-onset periodontitis patient with virus-associated hemophagocytic syndrome.

Virus-associated hemophagocytic syndrome (VAHS) is a disorder characterized by benign generalized histiocytic proliferation and marked hemophagocytosis associated with systemic viral infection. An immunodeficiency which includes an extremely decreased leukocyte and platelet count together with abnormalities in the CD4/CD8 ratio are the most common features of VAHS. Here we report an early-onset periodontitis (EOP) patient with VAHS from the standpoint of host-parasite interaction to understand the effect of this systemic disorder which might possibly influence susceptibility to periodontal disease. The patient is a 16-year-old Japanese male clinically diagnosed as having generalized EOP with slight gingival inflammation and moderate bone loss. This patient manifested VAHS at 3 years of age, and then had an unusual 4 recurrences (at 5, 7, 11, and 14 years old). Laboratory tests conducted include: 1) complete blood analyses: 2) peripheral neutrophil functions (chemotaxis, phagocytosis, superoxide production, and adherence); 3) peripheral lymphocyte subpopulations and functions, T-cell proliferative activity and productivity of cytokines (interleukin-2 [IL-2], interferon gamma [IFN-gamma], and tumor necrosis factor alpha [TNF-alpha]); 4) serum cytokine levels (IL-1 beta, IL-2, soluble IL-2 receptor [sIL-2R], IL-4, IL-6, IFN-gamma, and TNF-alpha; 5) serum immunoglobulin G (IgG) antibody titers against periodontopathic bacteria; 6) serological human leukocyte antigen (HLA) typing; and 7) determination of bacterial flora of the periodontal pockets. The results indicated that the patient's neutrophil chemotaxis and random migration were below the normal range. In lymphocyte examinations, T-cell proliferative activity, IL-2, and IFN-gamma productivity were elevated. Serum IFN-gamma level was also significantly higher than normal range. No specific periodontopathic bacteria were predominant in the periodontal pockets, however, the serum IgG titer against Porphyromonas gingivalis was elevated throughout the examination period. It is suggested that VAHS might be a possible risk factor for periodontal disease, and hence may serve as a model in understanding the role of host defense mechanisms in the establishment of inflammatory periodontal disease.