			Home About us Contact

Periradicular Lesions (periradicular + lesion)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Bacteria of asymptomatic periradicular endodontic lesions identified by DNA-DNA hybridization

DENTAL TRAUMATOLOGY, Issue 5 2000
J. J. Gatti
Abstract , Possible inclusion of contaminant bacteria during surgery has been problematic in studies of periradicular lesions of endodontic origin. Therefore, in this study, two different surgical techniques were compared. A second problem is that some difficult to cultivate species may not be detected using bacteriological methods. Molecular techniques may resolve this problem. DNA-DNA hybridization technology has the additional advantage that DNA is not amplified. The purpose of this investigation was to determine if bacteria from periradicular endodontic lesions could be identified using DNA-DNA hybridization. A full thickness intrasulcular mucoperiosteal (IS) flap (n=20) or a submarginal (SM) flap (n=16) was reflected in patients with asymptomatic apical periodontitis. DNA was extracted and incubated with 40 digoxigenin-labeled whole genomic probes. Bacterial DNA was detected in all 36 lesions. Seven probes were negative for all lesions. In patients with sinus tract communication, in teeth lacking intact full coverage crowns, and in patients with a history of trauma, 4,13 probes provided positive signals. Seven probes were positive in lesions obtained by the IS, but not the SM technique. Two probes were in samples obtained with the SM technique, but not the IS. Only Bacteroides forsythus and Actinomyces naeslundii genospecies 2 were present in large numbers using either the IS or the SM technique. The SM flap technique, in combination with DNA-DNA hybridization, appeared to provide excellent data pertaining to periradicular bacteria. These results supported other studies that provide evidence of a bacterial presence and persistence in periradicular lesions. [source]

Inflammatory infiltrate of chronic periradicular lesions: an immunohistochemical study

INTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2003
S. Liapatas
Abstract Aim, To determine the cellular profile of human chronic periradicular lesions using immunohistochemical methods in order to study the differences in the cell infiltrate of periradicular granulomas and cysts. Methodology, The study population consisted of 45 individuals without any systemic disease. Biopsies were obtained during periradicular surgery. Paraffin-embedded sections were stained by the avidin,biotin complex method (ABC), whilst cryostat tissue sections were stained using the alkaline phosphatase antialkaline phosphatase assay (APAAP). These methods are highly valid and sensitive using a panel of specific monoclonal antibodies: CD4, CD8, CD3, CD10, HLADR, CD20, CD45RO, CD68 and CD57. The 45 specimens were characterized by the use of both techniques. Results, The 45 specimens were histologically diagnosed as: 25 periradicular granulomas, 17 periradicular cysts and 3 scar tissues. No statistically significant differences were detected in the inflammatory infiltrate between periradicular granulomas and cysts. Observation of the sections showed that the majority of inflammatory cells consisted of T and B lymphocytes and macrophages. T and B lymphocytes were equally distributed in 60% of the cases. The T4/T8 ratio ranged approximately from 1 to 3 and greater, being consistent with inflammation of periradicular tissues. The final differentiation of B lymphocytes to plasma cells was also detected, whilst natural killer (NK) cells were found in only 10 cases (22%). Moreover, antigen presenting cells and T suppressor/cytotoxic cells were found to be associated with both pre-existing and newly formed epithelium. Conclusions, Periradicular granulomas and cysts represent two different stages in the development of chronic periradicular pathosis as a normal result of the process of immune reactions that cannot be inhibited. [source]

A new technique for the study of periapical bone lesions: ultrasound real time imaging

INTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2002
E. Cotti
Abstract Aim This study describes the use of a real time-ultrasound imaging technique (echography) for the study of periradicular lesions. Methodology Twelve patients with periapical lesions of endodontic origin, diagnosed with conventional clinical and radiographic examination, were examined further using echography at the site of the diagnosed lesions. Each lesion was echographically characterized and described by an expert echographist together with an endodontist. Once the major echographic features were identified, information on the size of the lesion, its content, and its vascular supply was obtained and recorded. A tentative differential diagnosis between a cyst and a granuloma was made based on the data. Results In all cases it was possible to obtain an echographic image. It was also possible to measure the lesions, to evaluate their content and to view their vascularization in different regions of the mouth. Conclusions Ultrasound real time imaging is a promising diagnostic technique in endodontology, but further work is required to refine the process. [source]

Investigation of bacterial communities associated with asymptomatic and symptomatic endodontic infections by denaturing gradient gel electrophoresis fingerprinting approach

MOLECULAR ORAL MICROBIOLOGY, Issue 6 2004
J. F. Siqueira Jr
The purpose of the present study was to investigate the bacterial communities associated with asymptomatic and symptomatic endodontic infections and to compare denaturing gradient gel electrophoresis (DGGE) fingerprinting patterns of these two clinical conditions. The root canal microbiota of teeth associated with asymptomatic or symptomatic periradicular lesions was profiled by the PCR-DGGE method and then compared, taking into consideration the banding patterns. Bacteria were present in all examined cases. Comparative analysis of the two clinical conditions revealed bands that were common to both symptomatic and asymptomatic cases, but most DGGE bands appeared to be unique for each clinical condition. No single band occurred in all profiles. The mean number of bands detected in the 16S rDNA community profiles were 12.1 ± 9.4 (range 2,29) for symptomatic samples and 6.7 ± 2.7 (range 2,11) for asymptomatic ones. Clustering methods and principal component analysis of DGGE banding pattern placed the samples according to the presence or absence of symptoms. Four intense bands that were excised from the gel and sequenced showed similarities to species of the Campylobacter genus (found in 5/12 asymptomatic and in 3/11 symptomatic cases), Fusobacterium genus (4/11 symptomatic cases), Acinetobacter genus (5/12 asymptomatic cases), and Enterobacteriaceae family (11/12 asymptomatic and 2/11 symptomatic cases). The profiles of the predominant bacterial community appeared to be unique for each individual. These findings confirm that endodontic infections are polymicrobial and showed that there are significant differences in the predominant bacterial composition between asymptomatic and symptomatic cases. [source]

Interleukin-6 and granulocyte-macrophage colony-stimulating factor in apical periodontitis: correlation with clinical and histologic findings of the involved teeth

MOLECULAR ORAL MICROBIOLOGY, Issue 1 2003
T. Radics
Apical periodontitis is characterized by the presence of immunocompetent cells producing a wide variety of inflammatory mediators. Releasing cytokines with long-range action, such as interleukin-6 (IL-6) and granulocyte-macrophage colony-stimulating factor (GM-CSF), apical periodontitis may induce changes in remote organs of the host. This study quantified the levels of IL-6 and GM-CSF in symptomatic and asymptomatic human periradicular lesions. Lesions were also characterized by size and histologic findings. Tissue samples were homogenized and supernatants were assayed using an enzyme-linked immunosorbent assay (ELISA). Correlations between cytokine levels and characteristic features (as single variables) of the lesions were analysed. There was a trend for higher levels of IL-6 and GM-CSF in symptomatic than in asymptomatic lesions, but the difference was not significant. Levels also tended to be higher in large than in small lesions, in polymorphonuclear (PMN) cell-rich than in PMN cell-poor samples, and in epithelialized than in non-epithelialized lesions. Significantly higher levels of IL-6 (778.1 ± 220.5 pg/,g) and GM-CSF (363.3 ± 98.4 pg/,g) were found in samples coincidentally possessing symptomatic and epithelialized features than in asymptomatic, small, PMN cell-poor, non-epithelialized lesions (IL-6: 45.2 ± 13.1 pg/,g and GM-CSF: 135.1 ± 26.4 pg/,g). These results suggest that symptomatic lesions containing epithelial cells represent an immunologically active stage of apical periodontitis, whereas asymptomatic, small, PMN cell-poor, non-epithelialized lesions represent healing apical lesions. [source]

Detection of Treponema denticola in endodontic infections by 16S rRNA gene-directed polymerase chain reaction

MOLECULAR ORAL MICROBIOLOGY, Issue 5 2000
J. F. Siqueira Jr.
A 16S rDNA-based polymerase chain reaction (PCR) method was used to detect the occurrence of Treponema denticola in root canal infections. Samples were collected from 21 single-root teeth having carious lesions, necrotic pulps and radiographic evidences of periradicular bone loss. DNA extracted from the samples was amplified using the PCR assay, which yielded specific fragment of T. denticola 16S rDNA. T. denticola was detected in 11 of 21 cases (52.4%), regardless of the presence or absence of symptoms. Since this spirochete was found in a relatively high percentage of the endodontic infections examined and because it is a pathogenic microorganism involved in periodontal diseases, there are reasons to believe that T. denticola can also participate in the pathogenesis of periradicular lesions of endodontic origin. [source]