Porphyromonas gingivalis promotes murine abdominal aortic aneurysms via matrix metalloproteinase-2 induction

Aoyama N, Suzuki J, Wang D, Ogawa M, Kobayashi N, Hanatani T, Takeuchi Y, Izumi Y, Isobe M. Porphyromonas gingivalis promotes murine abdominal aortic aneurysms via matrix metalloproteinase‐2 induction. J Periodont Res 2011; 46: 176–183. © 2010 John Wiley & Sons A/S Background and Objective: Abdominal aortic aneurysm (AAA) is a common and lethal disorder, and MMPs are highly expressed in AAA lesions. Large numbers of periodontopathic bacteria have been reported to be present in specimens obtained from the aortic walls of patients with an AAA. The purpose of this study was to analyze the influence of periodontopathic bacteria on AAA dilatation. Material and Methods: AAAs were produced in mice by the periaortic application of 0.25 m CaCl₂, and NaCl was used as a control. The mice were inoculated once weekly with live Porphyromonas gingivalis, live Aggregatibacter actinomycetemcomitans or vehicle. Results: Four weeks after the periaortic application of either CaCl₂ or NaCl, a significant increase was observed in the aortic diameter of P. gingivalis‐challenged mice compared with the vehicle control mice (p < 0.05), whereas there was no statistically significant increase in the aortic diameter of the A. actinomycetemcomitans‐challenged mice. Immunohistochemical analysis found significantly higher numbers of CD8‐positive and MOMA2‐positive cells and significantly higher levels of MMP‐2 in the aneurysmal samples of P. gingivalis‐challenged mice compared with control mice. Live P. gingivalis promoted a significant proliferation of splenocytes in comparison with P. gingivalis‐lipopolysaccharide and live A. actinomycetemcomitans (p < 0.05). Conclusion: These findings demonstrate that challenge with P. gingivalis, but not with A. actinomycetemcomitans, can accelerate, or even initiate, the progression of experimental AAA through the increased expression of MMPs.     

Warm gutta-percha obturation technique: a critical review

Cleaning and shaping the root canals play an important role to remove the organic debris within the endodontic system. The result, however, must be maintained over time through an effective root canal fillings preventing the entry of micro-organisms and tissutal fluid in the root canal system. Recently new materials have been introduced on the market, hence alternatives techniques for the root canals obturation have been developed and proposed. Even if cold lateral condensation is still considered the technique to refer to, there are numerous alternatives that use heat to achieve optimal adaptation of gutta-percha to the root canal space. The purpose of this work is to emphasize the positive aspect and points of weaknesses of different methods used for filling the root canals in order to allow the clinician to carry out choices as possible based on scientific evidence. Although many clinical trials still have not identified the superiority of one obturation technique over the others, the importance of this stage is objectively primary, so much that in the clinical practice we can notice an increasing success of endodontic treatment.     

Mucosal malignant melanomas in head and neck surgery: a retrospective study of six patients and review of the literature

Introduction

Of all malignant processes of the oral mucosa, 0.5% are malignant melanomas. Because of late diagnosis, pattern of growth, close proximity to the bone (particularly in palatinal localizations), and the correlated infiltration, malignant melanomas have a bad prognosis.

Patients and methods

In this retrospective study, six cases of patients with oral mucosal malignant melanoma are evaluated, and a critical review of the literature is presented. The female to male proportion was 1:1 with an average age of 60.2 years; all patients were treated between January 1999 and July 2007. A neck dissection was performed on two patients because of clinically positive lymph nodes; one patient received interleukin 2 therapy, and three patients received postoperative radiotherapy. Two male patients died.

Conclusions

We recommend biopsy on every growing lesion, pigmented or nonpigmented, for the required diagnosis and, in cases of malignant melanoma, wide excision as a second step. Neck dissections should be performed in patients with clinically positive lymph nodes. Concerning interleukin 2 therapy, further studies should be performed in order to evaluate a routine application.