Influence of solvent and a supplementary step with a finishing instrument on filling material removal from canals connected by an isthmus.

AIM: To evaluate the effectiveness of a solvent (eucalyptol) in improving filling material removal from canals connected by isthmuses, and the additional cleaning effect of a finishing instrument. METHODOLOGY: The mesial canals from 32 mandibular molars (Vertucci's type II morphology) were instrumented and filled with the single-cone technique using Reciproc R25 gutta-percha points (VDW, Munich, Germany) combined with Sealer 26 (Dentsply, Petrópolis, RJ, Brazil). Each root was then subjected to retreatment using the Mtwo instrument system (VDW), with or without a solvent (n = 16 per group). The volume of filling material in the canals was assessed by micro-computed tomographic (micro-CT) scans taken before and after retreatment. Canals with remnants of filling material received a supplementary procedure with the XP-endo Finisher R instrument (FKG Dentaire, La Chaux-de-Fonds, Switzerland), with or without eucalyptol, and another micro-CT scan was taken. All retreatment procedures were performed inside a cabinet under a controlled temperature (37 °C). Filling material removal was evaluated in the 5-mm apical canal system for the canal+isthmus space or the isthmus alone. Statistical analyses were performed to compare the removal of filling material with and without eucalyptol, and after a supplementary approach with XP-endo Finisher R. The level of significance was set at 5% for all statistical tests (P < 0.05). RESULTS: The amount of filling material removed from the canal+isthmus with Mtwo instruments was 83.2% when no solvent was used and 83.8% using the solvent (P > 0.05). When the isthmus area was evaluated separately, most specimens were associated with a reduction in the filling material, with no significant difference between the groups with or without using a solvent (P > 0.05). The supplementary step with XP-endo Finisher R significantly improved removal of filling material from both canal and isthmus area (P < 0.05), regardless of the use of a solvent (P > 0.05). CONCLUSION: The use of eucalyptol did not improve filling material removal from Vertucci's type II molar mesial canals and isthmuses. XP-endo Finisher R significantly enhanced removal of filling material from the canals and isthmuses.

Quantitative molecular and culture analyses of bacterial elimination in oval-shaped root canals by a single-file instrumentation technique.

AIM: Bacterial reduction in oval-shaped root canals by a single-instrument technique was compared ex vivo with a conventional nickel-titanium rotary technique. Data obtained from two quantification methods, quantitative real-time polymerase chain reaction (qPCR) and culture, were also compared. METHODOLOGY: Oval-shaped canals of extracted teeth contaminated with Enterococcus faecalis were instrumented using either a single Reciproc instrument or the BioRaCe instrument series. Bacteriological samples were taken before (S1) and after instrumentation (S2). Bacterial quantification was performed using qPCR and culture. RESULTS: Intragroup analysis showed that both protocols promoted a highly significant bacterial reduction (P < 0.001). Intergroup analysis (S2 samples) showed no significant differences between the two instrumentation systems (P > 0.05). As for the quantification methods, qPCR revealed significantly higher counts of E. faecalis in S1 than culture (P < 0.05), but no significant differences occurred for S2 (P > 0.05). CONCLUSION: The single-file technique was comparable with the conventional technique in oval-shaped canals provided the width of apical preparation, volume of irrigants and duration of irrigation are kept similar. No significant difference was observed for qPCR and culture in post-instrumentation samples, indicating that both methods can be reliably used for studies of antibacterial effectiveness.

Preliminary characterization and distribution of vicia villosa binding cells in human tonsils.

The lectin Vicia villosa (VV) has been used for the separation of human and murine contrasuppressor T cells. These cells were characterized in cryostat sections of human palatine tonsils by double staining with VV lectin and monoclonal antibodies to macrophages, lymphocytes and their subsets using a fluorescein-rhodamine technique. VV lectin had an affinity for the CD8+ subset of lymphocytes and for a subset of macrophages within the germinal centre. The number and distribution of VV lectin binding cells was studied in paraffin sections of formalin fixed tonsils by the avidin-biotin-peroxidase technique. Positive cells in the germinal centres, mantle, interfollicular zones and fibrous connective tissue septa were quantified using an image analyser. These were found in greatest density in the interfollicular zone, correlating with the known distribution of T cells in human palatine tonsils. The binding of VV lectin to a subset of macrophages appears not to have previously been described nor have VV lectin binding CD8+ lymphocytes been demonstrated in sections of human tissues.

A novel lamina lucida component of epithelial and endothelial basement membranes detected by LH39 monoclonal antibody.

The murine monoclonal antibody, LH39 was characterized in this study and appeared to bind to a novel basement membrane epitope. This antigen was expressed in the epithelial basement membrane of human tissue derived from all three germ cell layers and in basement membranes surrounding small blood vessels within the stroma of all organs examined. LH39 antigen could be first detected in fetal skin at the dermo-epidermal junction at 7 weeks estimated gestational age but was not present in the dermal vasculature until 16 weeks. When tested against tissue from a range of lower mammalian species, LH39 antigen appeared to be primate-specific. The epithelial basement membrane zone in organotypical cultures, where there is de novo synthesis of basement membrane components, contained abundant LH39 antigen in contrast to other basement membrane components, type IV collagen, laminin, and type VII collagen. Ultrastructural localization of LH39 epitope, using immunogold electron microscopy on unfixed freshly frozen tissue, was to the lamina lucida. No cross-reactivity could be detected between LH39 and laminin, fibronectin, and collagens I, III, IV, and V using the ELISA assay. In vitro studies with a range of proteolytic enzymes suggested that the antigen was non-collagenous in nature. LH39 precipitated a polypeptide with a molecular weight of 185 kD from extracts of metabolically labelled cultured keratinocytes, and polypeptides of 185 and 200 kD from the culture medium. The tissue distribution of LH39 antigen suggested that it may be an epitope within anchoring filaments. Potential applications of this antibody include the study of benign and malignant human vascular disorders, diseases and tumours associated with angiogenesis, epithelial neoplasms, and conditions of tissue regeneration and repair, such as wound healing.

The distribution of LH39 basement membrane epitope in the tumour stroma of oral squamous cell carcinomas.

LH39 monoclonal antibody detects a novel component of epithelial and endothelial basement membranes. The expression of LH39 antigen was investigated by immunohistochemistry in 55 oral squamous cell carcinomas and compared with 15 pyogenic granulomas of skin and oral mucosa, 20 non-specific oral ulcers, and 20 specimens of normal oral mucosa. The distribution of this basement membrane epitope was compared with that of other basement membrane components, type IV collagen, and laminin. LH39 monoclonal antibody labelled basement membrane surrounding small blood vessels in normal human organs. In oral squamous cell carcinomas, in contrast to the other basement membrane antigens, the LH39 epitope was not detectable in vessels within histologically recognizable tumour stroma. Neovascularization is known to attend malignant neoplasms and this finding was interpreted as absence of LH39 antigen within newly formed vessels. In support of this hypothesis, LH39 immunoreactivity was absent in newly formed blood vessels within pyogenic granulomas and the granulation tissue within ulcers. As increasing neovascularization is reported to correlate with a rising rate of metastasis, assessment of tumour angiogenesis may be of value in selecting patients for initial aggressive therapy.

Hermafroditismo em jabuti piranga (Geochelone carbonaria) / Hermaphroditism in jabuti piranga (Geochelone carbonaria)

Hermaphroditism is a term used to describe animals that have genitals of both genders. This anomaly has been described in reptiles such as lizards and snakes. The jabuti species Geochelone carbonaria hull has a high and very concave bone which is covered by corneal plates with yellow spots at the center, and collect the neck caudally into the hull. Although sexual dimorphism is externally quite clear, the females have straight plastron, while the male presents a clear concave plastron that serves to facilitate the mounting and a well developed penis having the size of the animal body. However, hermaphroditism in this species can only be confirmed with additional exams.

Avaliação de uma metodologia profilática contra a mastite clínica em ovelhas da raça Santa Inês / Evaluation of a prophylactic method against clinical mastitis in Santa Inês ewes

Mastitis is an important problem for the Santa Inês ewes and is a disease strongly related to the management carried out in the herd. A comparative study was carried out between the proposed method based on drying (treatment) and the traditional method (control). Sixty-two Santa Inês ewes raised in a semi-extensive system were divided in two groups of 31 ewes each: treatment group (G1) and control group (G2). The animals were monitored each week searching for clinical sings of mastitis. In 8.4 percent of G1 and 41.3 percent of G2 animals, the udder was warm and hyperemic. The presence of residual milk was lower in G1 (24.3 percent) compared to those of G2 (74.2 percent). The proposed treatment for the control of ovine mastitis significantly reduced the frequency of the clinical signs of the disease.