Dennis de Carvalho Ferreira

Supplementing the Antimicrobial Effects of Chemomechanical Debridement with Either Passive Ultrasonic Irrigation or a Final Rinse with Chlorhexidine: A Clinical Study

INTRODUCTION The ability of 2 different approaches to supplement the antimicrobial effects of chemomechanical debridement in infected root canals was compared in vivo. METHODS Samples from necrotic root canals of teeth with apical periodontitis were taken at the baseline (S1), after preparation with rotary nickel-titanium BioRaCe instruments and 2.5% NaOCl irrigation (S2), and then after either passive ultrasonic irrigation (PUI) for activation of NaOCl (n = 13) or a final rinse with 2% chlorhexidine (CHX) (n = 14) (S3). The incidence of positive culture for bacteria and fungi as well as positive broad-range polymerase chain reaction (PCR) results for bacteria, fungi, and archaea was determined. RESULTS All S1 samples were positive for bacteria in all methods. Fungi were not detected, and archaea occurred in only one S1 sample. Treatment procedures were significantly effective in reducing the incidence of positive culture and PCR results. Although both supplementary approaches reduced the incidence of positive bacteriologic results when compared with postinstrumentation samples, reduction was not statistically significant (P > .05). There was no significant difference for intergroup comparisons either (P > .05). CONCLUSIONS Although supplementary disinfection with either PUI or a final rinse with CHX can reduce the number of cases with positive culture and PCR results for bacteria, many cases still remain with detectable bacteria in the main root canal. Research on alternative or supplementary antimicrobial methods or substances should be encouraged.

Identification of herpesviruses types 1 to 8 and human papillomavirus in acute apical abscesses.

INTRODUCTION It has been suggested that viruses, especially herpesviruses, can play a role in the pathogenesis of marginal and apical periodontitis. This study aimed to detect herpesviruses types 1 to 8, namely herpes simplex virus (HSV-1/2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), human herpesvirus-6 (HHV-6), human herpesvirus-7 (HHV-7), and human herpesvirus-8 (HHV-8) as well as human papillomavirus (HPV) in acute apical abscesses. METHODS Twenty-four samples were taken by aspiration of the purulent exudate from acute apical abscesses. DNA extracted from clinical samples served as a template in single or nested polymerase chain reaction (PCR) assays for the detection of the target viruses. RESULTS Control PCR reactions with β-globin gene primers revealed that all samples but one had detectable human DNA. Of the 23 abscess samples positive for the β-globin gene, 14 (61%) were positive for at least one of the target human viruses. Thirteen (56.5%) cases had herpesvirus: HHV-8 occurred in 11 (48%), VZV and HHV-6B in two (9%), and HHV-7 and HSV-1/2 in one (4%). EBV and HCMV were not present in any of the examined samples. HPV was detected in three (13%) abscess samples. Viral coinfection was found in five cases, with one case harboring three of the targeted viruses. CONCLUSION A large number of abscess samples were positive for at least one target virus. Unexpectedly, HHV-8 was for the first time detected and in a high prevalence. Papillomavirus and other herpesviruses were also found for the first time in endodontic abscesses. Although these findings suggest an association, the specific role of viruses in the pathogenesis of acute apical abscesses awaits further clarification.

Molecular microbiological evaluation of passive ultrasonic activation as a supplementary disinfecting step: a clinical study.

INTRODUCTION This in vivo study used molecular microbiology methods to evaluate the effects of passive ultrasonic irrigation (PUI) as a supplementary disinfecting step after root canal preparation. METHODS Samples were taken from 10 necrotic root canals of teeth with apical periodontitis before (S1) and after rotary nickel-titanium instrumentation using 2.5% NaOCl as the irrigant (S2) and then after PUI for NaOCl activation (S3). The parameters examined included the incidence of positive broad-range polymerase chain reaction (PCR) results for bacterial presence, the impact on bacterial diversity evaluated by PCR-denaturing gradient gel electrophoresis (DGGE), the quantitative bacterial reduction determined by real-time PCR, and the identification of persistent species by clone library analysis. RESULTS All S1 samples were positive for bacteria in all tests. Treatment procedures were significantly effective in reducing the incidence of positive results for bacteria, the number of bacterial cells (infectious bioburden), and the bacterial diversity (number of species and abundance). However, the supplementary PUI approach did not succeed in significantly enhancing disinfection beyond that achieved by chemomechanical preparation. Several bacterial species/phylotypes were identified in post-treatment samples that were positive for bacteria. CONCLUSIONS Findings from this clinical study including a small sample size suggest that PUI can be ineffective in significantly improving disinfection of the main root canal after chemomechanical procedures.

Clinical antimicrobial efficacy of NiTi rotary instrumentation with NaOCl irrigation, final rinse with chlorhexidine and interappointment medication: a molecular study

AIM To evaluate clinically the antibacterial effects of root canal treatment procedures using molecular microbiology analyses. METHODOLOGY Samples were taken from 14 necrotic root canals of teeth with apical periodontitis before (S1) and after instrumentation with NaOCl irrigation (S2), a final rinse with chlorhexidine (CHX) (S3) and then one-week interappointment medication with calcium hydroxide/CHX paste (S4). The parameters examined included the following: incidence of positive broad-range PCR results for bacterial presence; impact on bacterial community structures evaluated by PCR-Denaturing Gradient Gel Electrophoresis (DGGE); quantitative bacterial reduction determined by real-time PCR; and identification of bacterial persisters by cloning and sequencing. Data from the different tests were subjected to statistical analyses and diversity indicator calculations. RESULTS All S1 samples were positive for bacteria in all tests. Treatment procedures promoted a decrease in microbial diversity and significantly reduced the incidence of positive results and the bacterial counts (P < 0.05). In general, each subsequent treatment step improved disinfection. No specific taxon or community pattern was associated with post-treatment samples. CONCLUSION Supplementary steps consisting of a final rinse with CHX followed by calcium hydroxide interappointment medication promoted further decrease in the bacterial bioburden to levels significantly below those achieved by the chemomechanical procedures alone. Because the long-term outcome of root canal treatment is dependent upon maximal bacterial reduction, the present results are of clinical relevance.

Viral-bacterial associations in acute apical abscesses.

OBJECTIVE Viral-bacterial and bacterial synergism have been suggested to contribute to the pathogenesis of several human diseases. This study sought to investigate the possible associations between 9 candidate endodontic bacterial pathogens and 9 human viruses in samples from acute apical abscesses. STUDY DESIGN DNA extracts from purulent exudate aspirates of 33 cases of acute apical abscess were surveyed for the presence of 9 selected bacterial species using a 16S ribosomal RNA gene-based nested polymerase chain reaction (PCR) approach. Single or nested PCR assays were used for detection of the human papillomavirus (HPV) and herpesviruses types 1 to 8. RESULTS Two-thirds of the abscess samples were positive for at least one of the target viruses. Specifically, the most frequently detected viruses were HHV-8 (54.5%); HPV (9%); and varicella zoster virus (VZV), Epstein-Barr virus (EBV), and HHV-6 (6%). Bacterial DNA was present in all cases and the most prevalent bacterial species were Treponema denticola (70%), Tannerella forsythia (67%), Porphyromonas endodontalis (67%), Dialister invisus (61%), and Dialister pneumosintes (57.5%). HHV-8 was positively associated with 7 of the target bacterial species and HPV with 4, but all these associations were weak. Several bacterial pairs showed a moderate positive association. Viral coinfection was found in 6 abscess cases, but no significant viral association could be determined. CONCLUSIONS Findings demonstrated that bacterial and viral DNA occurred concomitantly in two-thirds of the samples from endodontic abscesses. Although this may suggest a role for viruses in the etiology of apical abscesses, the possibility also exists that the presence of viruses in abscess samples is merely a consequence of the bacterially induced disease process. Further studies are necessary to clarify the role of these viral-bacterial interactions, if any, in the pathogenesis of acute apical abscesses.

Is there interaction between gut microbial profile and cardiovascular risk in chronic kidney disease patients

AIM To evaluate the gut microbial profile in chronic kidney disease (CKD) patients and evaluate the possible relationship with inflammation and cardiovascular risk. PATIENTS & METHODS Markers inflammation plasma and bacterial community profile (denaturing gradient gel electrophoresis) were analyzed. RESULTS The average number of bands was not different in healthy individuals and CKD patients. The number of bands was negatively associated with plasma levels of VCAM-1 in patients. Flavobacteriaceae bacterium and Listeria monocytogenes were found in patients and Lachnospiraceae bacterium and Butyrivibrio crossotus in healthy individuals. CONCLUSION Although CKD patients did not present altered gut microbial profile, the sequencing of bands suggested a different microbiota between groups. The result suggests a possible relationship between gut microbiota and cardiovascular risk in CKD patients.

Current status of herpesvirus identification in the oral cavity of HIV-infected children

INTRODUCTION Some viruses of the Herpesviridae family are frequently the etiologic agents of oral lesions associated with HIV. The aim of this study was to identify the presence of herpes simplex virus types 1 and 2 (HSV-1, HSV-2), Varicella Zoster virus (VZV), Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), human herpesvirus type 6, type 7 and type 8 (HHV-6, HHV-7 and HHV-8) in the oral cavity of HIV-infected children/adolescents and verify the association between viral subtypes and clinical factors. METHODS The cells of oral mucosa were collected from 50 HIV infected children/adolescents, 3-13 years old (mean age 8.66). The majority (66%) of selected were girls, and they were all outpatients at the pediatric AIDS clinic of a public hospital in Rio de Janeiro. Nested-PCR was used to identify the viral types. RESULTS Absence of immunosuppression was observed in 66% of the children. Highly active antiretroviral therapy (HAART) was used by 72.1% of selected and moderate viral load was observed in 56% of the children/adolescents. Viral types were found in 86% of the children and the subtypes were: HSV-1 (4%), HSV-2 (2%), VZV (4%), EBV (0%), HCMV (24%), HHV6 (18%), HHV-7 (68%), HHV8 (0%). CONCLUSIONS The use of HAART has helped to reduce oral lesions, especially with herpes virus infections. The health professionals who work with these patients should be aware of such lesions because of their predictive value and the herpes virus can be found circulating in the oral cavity without causing lesions.

Human papillomavirus coinfection in the oral cavity of HIV-infected children.

Aim To identify the early presence of human papillomavirus (HPV) DNA in the oral cavity of HIV-infected children. Methods The study group comprised 50 HIV-infected children and 50 healthy aged paired controls. Oral mucosa samples were collected by swab, and a 450 bp HPV DNA fragment was amplified by PCR, using degenerate consensus primers directed to the L1 gene. HPV typing was performed using specifics primers for types 6/16 and 11/18. Results All HPV co-infected children had vertical transmission of HIV. HPV DNA was detected in 6/50 (12.0%) of HIV children and three control group individuals 3/50 (6.0%) (p>0.01). In the HIV group, one had type 11, in the control group one had co-infection of types 11/16, and the others had type 16 and 18. Conclusions Based upon the results, it is concluded that HPV DNA may be present in HIV disease, but no association with immunosuppression, delivery, or medical records (CD4 cell count, viral load and use of highly active antiretroviral therapy) was observed, and no differences could be observed between the groups either.

Impact of low-intensity laser on the suppression of infections caused by Herpes simplex viruses 1 and 2: in vitro study

The use of low-level laser to suppress infections caused by Herpes simplex viruses 1 and 2 was evaluated after one to five applications. A gradual reduction in replication of Herpes simplex viruses 1 and 2 was observed, with 68.4% and 57.3% inhibition, respectively, after five applications, thus favoring its clinical use.

Oral squamous papilloma and condyloma acuminatum as manifestations of buccal-genital infection by human papillomavirus

Genital infection by human papillomavirus (HPV), a sexually transmitted disease (STD), has increased considerably due to the changes in sexual behaviour and an increase in the practice of oral sex. HPV, in a parallel manner, has been closely studied due to its oncogenic potential. We present the case of a 27-year-old patient, with a multi-partner sexual history and frequent practice of oral sex, who suffered from warts lesions on the genitalia and tongue. Squamous papilloma was diagnosed from a tongue biopsy. The treatment of the oral lesion was by way of surgery, without relapse in the first two years. Our discussion in this report is regarding the HPV infection in the oral cavity.