Association between human cytomegalovirus and periodontitis: A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE: Human cytomegalovirus (HCMV) has been associated with periodontitis and apical periodontitis. The objective of this systematic review was to evaluate the association between HCMV and periodontitis, and apical periodontitis of endodontic origin. MATERIAL AND METHODS: A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines and registered in the International prospective register of systematic reviews (PROSPERO). The search for potential studies was performed in MEDLINE via PubMed, Scopus, and SciELO. A quality assessment of the studies, publication bias analysis, and meta-analysis was performed. The results are presented in odds ratio with 95% confidence interval with the corresponding Forest plot. Sensitivity analysis was performed to evaluate the consistency of the results. RESULTS: Thirty-two studies were included in the quantitative and qualitative analyses. Of these, 26 were in periodontitis patients and 6 in apical periodontitis patients. Forest plot of combined studies revealed significant increased odds for periodontitis when subgingival HCMV was detected (OR 5.31; 95% CI 3.15-8.97). Sensitivity analysis based on quality of the included studies, showed consistent results. In contrast, the odds ratio for apical periodontitis when HCMV was detected from apical lesions was not statistically significant (OR 3.65; 95% CI 0.49-27.10). CONCLUSIONS: The results from the meta-analysis indicate that HCMV is significantly associated with periodontitis. In contrast, HCMV infection is not associated with apical periodontitis.

Notch - a possible mediator between Epstein-Barr virus infection and bone resorption in apical periodontitis.

Objectives: This study aimed to investigate whether Epstein-Barr virus (EBV) positive periapical lesions exhibited higher mRNA levels of Notch signalling molecules (Notch2 and Jagged1), bone resorption regulators (receptor activator of nuclear factor kappa-ß ligand (RANKL) and osteoprotegerin (OPG)), and proinflammatory cytokines (tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß) and IL-6) compared to EBV negative lesions. Additionally, the potential correlation between investigated molecules in periapical lesions was analyzed.Materials and methods: Sixty-four apical periodontitis lesions were obtained subsequent to standard apicoectomy procedure. The presence of EBV was determined using nested PCR. Based on the presence of EBV all periapical lesions were divided into two groups, 29 EBV positive and 35 EBV negative lesions. A reverse transcriptase real-time PCR was used to determine mRNA levels of Notch2, Jagged1, RANKL, OPG, TNF-α, IL-1ß and IL-6.Results: Significantly higher mRNA levels of Notch2, Jagged1, RANKL and IL-1ß were observed in EBV positive compared to EBV negative lesions. Significant positive correlation was present between Notch2 and Jagged1, Jagged1 and RANKL, and IL-ß and TNF-α in EBV positive periapical lesions.Conclusions: Notch signalling pathway may be involved in alveolar bone resorption in apical periodontitis lesions infected by EBV.

Levels of oxidative stress biomarkers and bone resorption regulators in apical periodontitis lesions infected by Epstein-Barr virus.

AIM: To investigate whether apical periodontitis lesions infected by Epstein-Barr virus (EBV) exhibit higher levels of oxidative stress biomarkers [8-hydroxydeoxyguanosine (8-OHdG) and oxidized glutathione (GSSG)] and bone resorption regulators [receptor activator of nuclear factor (NF-κB) ligand (RANKL) and osteoprotegerin (OPG)] compared to EBV-negative periapical lesions and healthy pulp tissues. METHODOLOGY: The experimental group consisted of 30 EBV-positive and 30 EBV-negative periapical lesions collected in conjunction with apicoectomy. The pulp tissues of 20 impacted third molars were used as healthy controls. The qualitative and quantitative analysis of EBV was performed by nested and real-time polymerase chain reaction (PCR), respectively. The levels of RANKL and OPG were analysed by reverse transcriptase real-time PCR. The levels of 8-OHdG and GSSG were determined by enzyme-linked immunosorbent assay (ELISA). Mann-Whitney U-test and Spearman's correlation were used for statistical analysis. RESULTS: The levels of RANKL, OPG, 8-OHdG and GSSG were significantly higher in apical periodontitis lesions compared to healthy pulp controls (P = 0.001, P < 0.001, P < 0.001 and P < 0.05, respectively). RANKL and OPG mRNA expression was significantly higher in EBV-positive compared to EBV-negative periapical lesions (P < 0.05). There was no significant correlation between EBV copy numbers and levels of RANKL, OPG, 8OH-dG and GSSG in apical periodontitis. CONCLUSION: Levels of bone resorption regulators and oxidative stress biomarkers were increased in apical periodontitis compared to healthy pulp tissues. EBV-positive periapical lesions exhibited higher levels of RANKL and OPG compared to EBV-negative periapical lesions. EBV may contribute to progression of apical periodontitis via enhanced production of bone resorption regulators.

Herpesviruses viral loads and levels of proinflammatory cytokines in apical periodontitis.

OBJECTIVES: This study aimed to analyse Epstein-Barr virus (EBV) and human cytomegalovirus (HCMV) viral loads in symptomatic and asymptomatic apical periodontitis lesions, to determine levels of TNF-α, IL-1ß and IL-6 in these lesions and to investigate a possible correlation between herpesviral copy numbers and levels of proinflammatory cytokines. MATERIALS AND METHODS: A total of 100 samples of apical periodontitis were subjected to HCMV and EBV copy numbers analysis by nested polymerase chain reaction (PCR) and TaqMan real-time PCR. The concentrations of TNF-α, IL-1ß and IL-6 were determined by ELISA method. SPSS software was used for statistical analysis. RESULTS: There were no significant differences in the occurrence of EBV and HCMV between symptomatic and asymptomatic periapical lesions (p = .686, p = .879, respectively). Only 12 of 74 EBV (16.2%) and four of 54 HCMV (13.5%) nested PCR-positive samples showed increased viral copy numbers above the limit of 125 copies/ml. There was no significant correlation between the levels of analysed proinflammatory cytokines and herpesviral copy numbers in our sample. CONCLUSION: The observed low viral loads point to a relatively rare occurrence of active EBV and HCMV infection in our sample. Latent herpesviral infection does not enhance the production of investigated proinflammatory cytokines.

The Role of Varicella Zoster Virus in the Development of Periapical Pathoses and Root Resorption: A Systematic Review.

INTRODUCTION: Varicella zoster virus (VZV) and subsequent herpes zoster (HZ) infection have been proposed as a causative agent of periapical pathoses and root resorption. This review aimed to identify, synthesize, and present a critical analysis of the available data on the association among VZV, subsequent HZ infection, and the development of periapical pathoses and root resorption and to analyze the level of evidence of available studies. METHODS: The literature search covered MEDLINE, Science Citation Index Expanded, and Scopus. A qualitative critical appraisal of the included articles was performed. RESULTS: The electronic database search yielded 66 hits from PubMed, 73 hits from Web of Science, and 107 from Scopus. Seven case reports and 3 cross-sectional studies were included in the final review. When summarized, in 7 patients with a history of a previous HZ attack and with no other apparent cause, 23 teeth were diagnosed with apical periodontitis, 8 teeth with internal and 1 tooth with external root resorption. The cross-sectional studies investigated the presence of VZV DNA in samples of acute apical abscess. The VZV DNA was found only in 2 of 65 samples. CONCLUSIONS: All studies included in this systematic review had a low level of evidence (4 and 5). Still, the potential role of VZV in the etiopathogenesis of periapical pathoses and root resorption cannot be ruled out. Future investigations should be directed toward the analysis of VZV pathologic effects on pulp blood vessels, which might cause local ischemia and tissue necrosis.

Multiple Apical Radiolucencies and External Cervical Resorption Associated with Varicella Zoster Virus: A Case Report.

Varicella zoster virus (VZV) is responsible for the primary infection chickenpox. After the initial infection, it remains latent but can reactivate, resulting in shingles (herpes zoster). Previous reports have implicated VZV in the pathogenesis of apical periodontitis, but the involvement of the virus has not been investigated fully. The present case describes a patient who suffered from a severe episode of shingles and subsequently developed periapical radiolucencies of all the teeth in the affected nerve distribution. Molecular and culture techniques showed the presence of VZV DNA in the root canal system in the absence of bacteria. This confirms that VZV can cause localized pulp necrosis and apical periodontitis. The lesions healed after endodontic treatment, implying chemomechanical debridement using sodium hypochlorite irrigation and a calcium hydroxide interim dressing may be effective against the virus.

Viruses in pulp and periapical inflammation: a review.

The presence of viruses in endodontic disease has been studied in the last decade. Their presence is associated with periapical radiolucency and with clinical findings, such as pain. The aim of this review is to analyze the scientific evidence currently published about viruses in pulp and periapical inflammation, and its possible clinical implications. A literature review was carried out using the Medline/Pubmed database. The search was performed, in English and Spanish, using the following keyword combinations: virus AND endodontic; virus AND periapical; virus AND pulpitis; herpesvirus AND periapical; papillomavirus AND periapical. We subsequently selected the most relevant studies, which complied with the search criterion. A total of 21 articles were included, of which 18 detected the present of viruses in the samples. In 3 of the studies, viral presence was not found in the samples studied. The Epstein-Barr virus was found in about 41 % of cases compared to controls, in which it was present in about 2 %. The main association between viruses and endodontic pathosis is between Cytomegalovirus and Epstein-Barr virus; these are found in 114 of the 406 samples of different endodontic pathosis. Some evidence supports that the Epstein-Barr virus is present in a significant number of endodontic diseases, without exact knowledge of their action in these diseases.

Prevalence of Human Cytomegalovirus and Epstein-Barr Virus in Chronic Periapical Lesions.

OBJECTIVE: The aim of this study was to investigate the presence of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in the tissue of chronic periapical lesions, and to compare the results in relation to the symptoms of patients and the size of the lesion. METHODS: Periapical lesions analyzed in the study were collected from the roots of the teeth indicated for extraction. Samples were divided according to the symptoms into groups of symptomatic and asymptomatic, and according the size into groups of small and large lesions. Polymerase chain reaction was used to detect HCMV and EBV. The amplification was performed in a DNA Thermal Cycler (Hybaid). RESULTS: Symptomatic lesions were 7.68 times more likely to be infected with HCMV than asymptomatic lesions (p < 0.001). Large symptomatic lesions were 73.50 times more likely to harbor HCMV than small symptomatic lesions (p < 0.001). Large symptomatic lesions were 7.64 times more likely to be infected with EBV than small symptomatic lesions (p = 0.05). Large symptomatic lesions were 5.38 times more likely to harbor dual HCMV/EBV infection than small symptomatic lesions (p = 0.115). CONCLUSION: Detection of HCMV and EBV in the samples of periapical lesions suggests an important role of herpesviruses in periapical tissue destruction.

Human Cytomegalovirus and Epstein-Barr Virus Genotypes in Apical Periodontitis Lesions.

INTRODUCTION: Different genotypes of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) possess specific pathogenic abilities because of various interactions with the host's immune system and differences in cell tropism. The aim of this study was to determine the distribution of HCMV and EBV genotypes in apical periodontitis lesions in relation to their clinical and histopathologic features. METHODS: One hundred samples of apical periodontitis lesions and 25 control samples (healthy pulp tissue) were collected. The presence of HCMV glycoprotein B (gB) and EBV nuclear antigen-2 genotypes was analyzed by nested polymerase chain reaction and restriction fragment length polymorphisms analysis. RESULTS: EBV and HCMV were detected in apical periodontitis lesions at significantly higher frequencies than in healthy pulp controls (P = .020 and P = .020, respectively). HCMV gB type II was significantly more frequent compared with gB type I in the examined groups (P = .036). No HCMV gB type III or IV products were found. In both periapical lesions and controls, EBV-1 occurred more often compared with EBV-2 (P = .001). Dual EBV and HCMV coinfection was more frequently detected in large-size periapical lesions (P = .038). CONCLUSIONS: Both HCMV and EBV are associated with inflammatory processes of periapical bone destruction. HCMV gB type II and EBV-1 are the most prevalent genotypes in apical periodontitis lesions.

Virus en patología pulpar y periapical. Revisión de la literatura / Viruses in pulp and peri apical pathosis. Review

Introducción: Las infecciones de origen endodóncico son infecciones polimicrobianas que pueden tener diversas manifestaciones clínicas y radiológicas. La presencia de virus en diferentes patologías pulpares y periapicales está en investigación con el fin de asociar su presencia con las lesiones radiolúcidas apicales y sus sintomatología. El objetivo de este estudio es analizar la evidencia científica disponible en la actualidad que relaciona la presencia de virus en diferentes patologías de endodoncia y sus posibles implicaciones clínicas. Métodos: Se hace una revisión en la base de datos Medline/Publine, utilizando diferentes parámetros de búsqueda, seleccionando posteriormente los artículos más relevantes, que cumplieron con el criterio de búsqueda. De igual manera se hace una búsqueda en Scielo e IME. Resultados: Se incluyeron un total de 21 artículos, de los cuales 17 detectan la presencia del virus en una de las muestras. En tres de los estudios, la presencia viral no se encontró en ninguna de las muestras estudiadas. Los virus que se encontraron con mayor frecuencia fueron el virus de Epstein-Barr y citomegalovirus; sin embargo, en algunos de estos estudios han aparecido agentes virales como el herpes humano 6 y 8 virus. La relación entre presencia viral y sintomatología no es posible detectarla en todos los estudios, y lo mismo sucede con el tamaño de la lesión. Conclusión: Es necesario examinar y comprender la relación microbiológica que se establece en las patologías de origen endodóncico, dando lugar a nuevas opciones terapéuticas y de tratamiento

Introduction: Infections of an endodontic origin are polymicrobiobial infections that can have diverse clinical and radiographic manifestations. Recently, the presence of viruses in different endodontic pathologies is a focus of new research, associating their presence with symptomology and with apical radiolucent lesions. The goal of this study is to analyze the scientific evidence available currently that relates the presence of viruses in different endodontic pathologies and their possible clinical implications. Methods: A revision was carried out of the Medline/Publine database, using different search parameters, subsequently selecting the most relevant articles, which complied with the search criterion. Results: A total of 21 articles were included, and 17 detected the presence of viruses in one of the samples. In 3 of the studies, viral presence was not found in any of the sample studied. The viruses that were most frequently found were the Epstein-Barr and Cytomegaloviruses; however in some of these studies viral agents have appeared such as the human herpes 6 and 8 viruses. The relation between viral presence and symptomology is not possible to detect in all of the studies, which is the same for the relationship with large apical lesions. Conclusion: It is necessary to examine and understand the microbiological relationships that are established in pathologies of endodontic origin, leading to new therapeutic and treatment options

Periodontopathogen and Epstein-Barr virus-associated periapical periodontitis may be the source of retrograde infectious peri-implantitis.

BACKGROUND: Herpesviral-bacterial synergism may play a role in periodontitis and peri-implantitis etiopathogenesis. Periapical periodontitis (PP) lesions can predict future apical peri-implantitis complications. PURPOSE: This pilot study aimed to substantiate herpesviral-bacterial coinfection in symptomatic (SP) and asymptomatic (AP) PP and assess associations with periodontopathogen salivary contamination in patients receiving implants. MATERIALS AND METHODS: Polymerase chain reaction (PCR)-based identification was performed on PP granulation tissue (GT) from 33 SP and AP patients and compared with unstimulated whole saliva. Quantitative PCR evaluated Epstein-Barr virus (EBV) and cytomegalovirus copy counts. RESULTS: SP GT had higher proportions of periodontopathogens. Symptomatic patients were 3.7 times more likely to be infected with EBV than AP (p = .07; 95% CI: 0.8-16.2). SP were 2.9, 2.1, 3.6, and 1.6 times more likely to be infected with Treponema denticola, Prevotella intermedia, Aggregatibacter actinomycetemcomitans, and Porphyromonas gingivalis, respectively. The odds ratio of EBV infecting PP lesions was two times higher in those positive for the virus in saliva. Saliva Tannerella forsythia-positive patients were 15 times more likely to present this pathogen in PP lesions (p = .038). Saliva EBV-positive individuals were 7 and 3.5 times more likely to yield GT contamination with T. forsythia and T. denticola, respectively. EBV copy counts were significantly higher in SP (p < .01). CONCLUSIONS: A causal association between EBV, specific bacterial anaerobic infection, and symptomatic PP is likely. EBV high prevalence underscores the viral etiological importance. Salivary EBV contamination is likely to be associated with viral and bacterial GT infection. Saliva PCR analysis can be a good predictor of GT specific infection and help establish antimicrobial therapy. If confirmed by prospective longitudinal clinical trials, antiviral therapy could possibly benefit SP and nonresponsive to treatment individuals and help prevent potential peri-implant infectious complications.

Human cytomegalovirus and Epstein-Barr virus in etiopathogenesis of apical periodontitis: a systematic review.

INTRODUCTION: During the last decade, a hypothesis has been established that human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) may be implicated in the pathogenesis of apical periodontitis. The aim of this review was to analyze the available evidence that indicates that HCMV and EBV can actually contribute to the pathogenesis of periapical lesions and to answer the following focused question: is there a relationship between HCMV and EBV DNA and/or RNA detection and the clinical features of human periapical lesions? METHODS: The literature search covered MEDLINE, Science Citation Index Expanded (SCIexpanded), Scopus, and The Cochrane Library database. Quantitative statistical analysis was performed on the pooled data of HCMV and EBV messenger RNA transcripts in tissues of symptomatic and asymptomatic periapical lesions. RESULTS: The electronic database search yielded 48 hits from PubMed, 197 hits from Scopus, 40 hits from Web of Science, and 1 from the Cochrane Library. Seventeen cross-sectional studies have been included in the final review. The pooled results from quantitative systematic method analysis showed no statistically significant relationship between the presence of HCMV and EBV messenger RNA transcripts (P = .083 and P = .306, respectively) and the clinical features of apical periodontitis. CONCLUSIONS: The findings of HCMV and EBV transcripts in apical periodontitis were controversial among the included studies. Herpesviruses were common in symptomatic and large-size periapical lesions, but such results failed to reach statistical significance. Further studies, including those based on an experimental animal model, should provide more data on herpesviruses as a factor in the pathogenesis of periapical inflammation.

Detection of human cytomegalovirus and Epstein-Barr Virus in symptomatic and asymptomatic apical periodontitis lesions by real-time PCR.

OBJECTIVES: Recent studies have investigated the occurrence of human cytomegalovirus and Epstein-Barr Virus in samples from apical periodontitis lesions and a role in the pathogenesis of this disease has been suggested. Because genotype distribution and seroprevalence of EBV and HCMV differ among populations, it is important to determine the presence of these viruses in endodontic periapical lesions of different populations. The aims of this study were to determine the presence of HCMV and EBV DNAs in samples from Turkish patients with symptomatic and asymptomatic apical periodontitis lesions using real-time polymerase chain reaction method and to evaluate their presence in both symptomatic and asymptomatic apical periodontitis lesions. STUDY DESIGN: Periapical samples were collected from 12 asymptomatic and 16 symptomatic periapical lesions in conjunction with apicectomy. HCMV and EBV DNAs were identified in the samples by real-time PCR. The chi-squared test with Yates's correction or the Fisher's exact test was used to analyse the significance of differences. RESULTS: HCMV DNA was detected in 10 of the 16 (62.5%) symptomatic and in five of the 12 (41.7 %) asymptomatic periapical study lesions. The EBV DNA was identified in seven of the 16 (43.7 %) symptomatic and three of the 12 (25 %) asymptomatic periapical lesions. The difference in occurrence of HCMV and EBV DNA between symptomatic and asymptomatic periapical lesions was not statistically significant. (All comparisons have p > 0.05). CONCLUSION: Our findings suggest that HCMV and EBV is a frequent inhabitant of both symptomatic and asymptomatic apical periodontitis lesions of endodontic origin in Turkish population.

Elevated tumor necrosis factor-alpha expression in periapical lesions infected by Epstein-Barr virus.

INTRODUCTION: In apical periodontitis, there is an intense inflammatory response to endodontopathogenic bacteria, an essential component of the pathogenic microbiota. The inflammation can be aggravated by herpesviruses acting as nonessential pathogens in periapical lesions. This study aimed to determine the levels of tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-ß) in periapical lesions in relation to local occurrence of Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), human herpesvirus 6 (HHV-6), and human herpesvirus 8 (HHV-8). METHODS: Fifty-eight samples with apical periodontitis and 20 clinically healthy gingival control tissues were collected. Viral DNA was determined with nested polymerase chain reaction, and cytokine mRNA expression was detected with real-time polymerase chain reaction assays. RESULTS: Periapical lesions harbored EBV (75.9%) and HHV-6 (22.4%) at significantly higher frequencies compared with controls (P < .000001 and P < .05, respectively), whereas HCMV (12%) and HHV-8 (0%) occurred rarely. The median TNF-α expression was 13 times higher (P < .001) and TGF-ß expression was 5 times higher in periapical lesions than in controls (P < .001). TNF-α expression was significantly higher in EBV-positive lesions than in EBV-negative lesions (P = .032). Presence of symptoms, lesion size, and infection by HCMV or HHV-6 had no significant association with either TNF-α or TGF-ß expression. CONCLUSIONS: The herpesviral component of the endodontic microbiota did not correlate with TGF-ß expression, whereas EBV infection was associated with a median 1.5 times further elevation of the high TNF-α expression characteristic for periapical lesions.

Efficacy of bacteriophage treatment on Pseudomonas aeruginosa biofilms.

INTRODUCTION: Bacterial viruses (phages) have been used successfully in the treatment of animal and human bacterial infections. This study examined the potential use of phage therapy against Pseudomonas aeruginosa strain PA14 biofilms in a root canal model. METHODS: Part 1: The 24-hour and 96-hour PA14 biofilms grown in microplates were treated with phages identified as possessing potential biofilm-degrading activities, and the post-treatment bacterial biomass was quantified by using crystal violet staining. Part 2: The 24-hour and 96-hour PA14 biofilms grown in prepared root canals of extracted human mandibular incisors were treated with phages identified with potential biofilm-degrading activities. Post-treatment intracanal samples were taken by using paper points and round burs to assess phage and bacterial counts. RESULTS: Part 1: We identified 2 phages (JBD4 and JBD44a) with putative biofilm-degrading activities. Treatment of PA14 biofilms with these phages produced a significant reduction in the mean percentage of biomass in 24-hour (P< .05) and 96-hour (P= .08) biofilms. Part 2: In 24-hour and 96-hour PA14 biofilms in a root canal model, no significant difference was found in the number of colony-forming units after phage treatment (P> .05). CONCLUSIONS: Phage application significantly reduced the biomass of 24-hour and 96-hour PA14 biofilms grown on microplates but did not produce significant reduction of 24-hour or 96-hour PA14 biofilms grown in the extracted tooth model.

[The prevalance of herpesviruses in human apical periodontitis samples]. / Herpeszvírusok elofordulása humán periodontitis apicalis mintákban.

Apical periodontitis is primarily initiated by the endodonto-patogen bacteria spreading from the inflamed or necrotic pulp tissues to the periapical area. Nevertheless, findings within the past years have established a pathogenic role of human herpesviruses such as Epstein-Barr virus (EBV) and human cytomegalovirus (HCMV) in periapical inflammations. The authors analysed the prevalence, activity and disease association of EBV, HCMV and human herpesvirus 6 (HHV-6) in 40 apical periodontitis samples and 40 healthy pulp controls. Based on the viral DNA results, EBV (29/40) was the most frequent herpesvirus in apical periodontitis, followed by HHV-6 (8/40) and HCMV (4/40). According to the mRNA results approximately two-third of the EBV DNA-positive lesions had active EBV infections. However, the HHV-6 and the HCMV infections seemed to be of latent state. Our findings suggest that EBV and HHV-GB infections primarily occurred in large sized and symptomatic periapical lesions. The co-occurrence of large lesion size and active EBV infection was strongly associated (OR = 8.80) with the symptomatic manifestation of apical periodontitis.

Herpesvirus carriage in saliva and posttreatment apical periodontitis: searching for association.

OBJECTIVE: Herpesvirus infection can cause immunosuppression and then act as a modifier of apical periodontitis, influencing the disease severity and response to treatment. The purpose of this study was to investigate if herpesvirus infection, as inferred by salivary carriage, may influence the endodontic treatment outcome. STUDY DESIGN: The study population included 72 patients who had root canals treated more than 1 year previously because of necrotic pulps and apical periodontitis. At the follow-up examination, 27 of these patients presented with posttreatment apical periodontitis (failure) and 45 individuals exhibited healed/healing periradicular tissues (success). Saliva was collected from these individuals, DNA was extracted, subjected to multiple displacement amplification, and screened by polymerase chain reaction (PCR) assays for the presence of 6 herpesviruses: herpes simplex virus types 1 and 2 (HSV-1/2), Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), human herpesvirus-6 (HHV-6), and human herpesvirus-8 (HHV-8). RESULTS: Except for HSV-1/2, all other herpesviruses were detected in saliva from both healed/healing and diseased groups. HHV-8 was the most frequent herpesvirus found in saliva (84% in success, 89% in failure), followed by HCMV (22% in success, 30% in failure), EBV (16% in success, 18.5% in failure) and HHV-6 (7% in success, 15% in failure). No significant association of herpesvirus carriage in saliva with poor treatment outcome was discernible in the population studied (P > .05). CONCLUSIONS: Data from the present study suggest that herpesvirus infection may not influence the outcome of endodontic treatment. Further longitudinal studies are warranted to confirm these findings.

Association of human herpesvirus 6 subtypes with symptomatic apical periodontitis.

OBJECTIVE: The occurrence of human herpesvirus (HHV) 6 subtypes A and B in apical periodontitis was determined. The relationship of HHV-6 subtypes to other disease associated herpesviruses, i.e., Epstein-Barr virus (EBV) and human cytomegalovirus, was also investigated. STUDY DESIGN: Forty apical periodontitis samples (17 symptomatic and 23 asymptomatic) and 40 healthy pulp control samples were collected. Nested polymerase chain reaction was used to detect HHV-6 DNA. RESULTS: HHV-6 DNA was observed in significantly higher frequencies in apical periodontitis samples than in control samples (20% vs. 2.5%; P = .03). Further classification of apical lesions revealed that subtype B of HHV-6 was significantly associated with large-sized and symptomatic lesions (P < .01). Thirty-one apical lesions (77%) harbored ≥1 of the tested herpesviruses: EBV was the most frequent herpesvirus (72.5%) in apical periodontitis, followed by HHV-6 (20%). CONCLUSION: Our findings suggest that EBV and HHV-6B infections can be associated with symptomatic apical periodontitis.

Prevalence and activity of Epstein-Barr virus and human cytomegalovirus in symptomatic and asymptomatic apical periodontitis lesions.

INTRODUCTION: Apical periodontitis is a polymicrobial inflammation with a dominant flora of opportunistic Gram-negative bacteria; however, a pathogenic role of human herpesviruses such as Epstein-Barr virus (EBV) and human cytomegalovirus (HCMV) has been implicated recently. The aims of this study were to determine the prevalence, activity, and disease association of EBV and HCMV in apical periodontitis in an Eastern Hungarian population. METHODS: Forty samples with apical periodontitis (17 symptomatic and 23 asymptomatic) and 40 healthy pulp controls were collected. EBV and HCMV prevalences were measured by polymerase chain reaction (PCR) detection of the viral DNA and viral activity was tested by reverse-transcription PCR amplification of viral messenger RNA. RESULTS: EBV DNA and EBNA-2 messenger RNA were found in apical periodontitis lesions at significantly (p < 0.0001) higher frequencies (72.5% and 50%, respectively) than in controls (both 2.5%). The occurrence of HCMV infection was rare in both apical lesions (10%) and controls (0%). The presence of EBV DNA in apical lesions was associated significantly with large (> or = 5 mm) lesion size (p = 0.02) but not with symptoms (p = 0.30). Symptomatic manifestation was significantly associated with the co-occurrence (odds ratio [OR], 8.80; 95% confidence interval [CI], 1.69-45.76) but not the sole occurrences of EBNA-2 messenger RNA (OR, 2.29; 95% CI, 0.48-11.06) and large lesion size (OR, 4.02; 95% CI, 0.81-19.89). CONCLUSION: EBV infection is a frequent event in apical periodontitis, whereas the involvement of HCMV still remains to be elucidated. This study showed that symptomatic manifestation was likely to occur if a large-sized apical periodontitis lesion is aggravated with active EBV infection.

Bacteriophages induced from lysogenic root canal isolates of Enterococcus faecalis.

INTRODUCTION: Bacterial viruses play crucial roles in the pathogenesis of many systemic diseases. They are known to inhabit the oral cavity, both as free virions and as prophages in lysogenic bacterial strains; however, there has been no report of bacteriophages in endodontic infections. In this study, we sought to detect, isolate, and describe temperate bacteriophages harbored by Enterococcus faecalis strains isolated from endodontic infections. METHODS: Ten E. faecalis strains were isolated from root canals of teeth undergoing retreatment following unsuccessful endodontic therapy. Mitomycin C was used to induce any prophages present in the bacterial isolates. The induced phages were purified and examined using electron microscopy. The DNA extracted from one of the phage isolates was subjected to restriction endonuclease digestion and agarose electrophoresis analysis. RESULTS: Lysogeny was demonstrated in 4 of the 10 E. faecalis strains. Three of the lysogenic strains yielded phages exhibiting a Siphoviridae morphology, with long, non-contractile tails 130 nm in length, and spherical/icosahedral heads 41 nm in diameter. The virus induced from the fourth lysogenic E. faecalis strain had a contractile tail characteristic of Myoviridae. Restriction endonuclease analysis of NsiI and NdeI DNA fragments from one of the Siphoviridae phage isolates (phage phiEf11) indicated a genome size of approximately 41 kbp. CONCLUSION: This is the first report of lysogenic bacteria and their inducible viruses in infected root canals.