114 resultados para Canal 2

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


Relevância:

60.00% 60.00%

Publicador:

Resumo:

The present study reveals that the excretory system of Glossoscolex paulistus is formed by open holonephridia (exonephridia). It is noticed that different zones are recognized in the nephridial canal, with defined histological and histochemical characteristics: 1) primary canal; 2) lobed canal; 3) first rounded segment; 4) afferent thin segment; 5) efferent thin segment; 6) second rounded segment; 7) ciliary tube; 8) clear canal; 9) pigmented canal; 10) intermediate canal; 11) bladder; 12) terminal canal; 13) nephridiopore. All these regions are intercellular and cilia are found in regions 1, 2, 3, 6, 7 and 13. The connections between afferent and efferent capillary of the vascular supply of the nephridium are made of capillary loops and dilatations which we call glomeruli in this paper. Filtering functions are suggested for the glomerulus. The response of the lobed canal and the first and second rounded segments to Gomori's reaction is strongly positive and this is found to coincide with the largest concentration of glomeruli in the main loops 1 and II, that suggests a higher filtration capacity for the canal and segments.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The aim of the present study was to evaluate the in vivo antimicrobial activity of 2% chlorhexidine gluconate (FCFRP-USP) used as a root canal irrigating solution in teeth with pulp necrosis and radiographically visible chronic periapical reactions. Culture techniques and measurement of the inhibition zone were used. Twenty-two root canals of incisors and molars of 12 patients were used. After accessing the canal, the first root canal sample was collected with two sterile paper points that were transferred to a tube containing reduced transport fluid. The root canal was instrumented using chlorhexidine solution. A small sterile cotton pellet was placed at the root canal entrance, and the cavity was sealed with zinc oxide-eugenol cement. The canals were maintained empty for 48 h. Three sterile paper points were then introduced to absorb the root canal fluid (second sample). One paper point was placed on an agar plate inoculated with Micrococcus luteus ATCC 9341 and incubated for 24 h at 37°C, and the other two were submitted to microbiological evaluation. Present in 10 cases at baseline, mutans streptococci was reduced by 100% at the second assessment. Treatment showed an efficiency of 77.78% for anaerobic microorganisms at the second assessment. These data suggest that chlorhexidine prevents microbial activity in vivo with residual effects in the root canal system up to 48 h. Copyright © 1999 by The American Association of Endodontists.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

OBJECTIVE: The purpose of this study was to evaluate the distribution of microorganisms in the root canal system (RCS) and periapical lesions of dogs' teeth after rotary instrumentation and placement of different calcium hydroxide [Ca(OH)2]-based intracanal dressings. MATERIALS AND METHODS: Chronic periapical lesions were experimentally induced in 80 premolar roots of four dogs. Instrumentation was undertaken using the ProFile rotary system and irrigation with 5.25% sodium hypochlorite. The following Ca(OH) 2-based pastes were applied for 21 days: group 1 - Calen (n=18); group 2 - Calen+CPMC (n=20); group 3 - Ca(OH)2 p.a. + anaesthetic solution (n=16) and group 4 - Ca(OH)2 p.a.+ 2% chlorhexidine digluconate (n=18). Eight root canals without endodontic treatment constituted the control group. Histological sections were obtained and stained with Brown & Brenn staining technique to evaluate the presence of microorganisms in the main root canal, ramifications of the apical delta and secondary canals, apical cementoplasts, dentinal tubules, areas of cemental resorption and periapical lesions. The results were analyzed statistically by the Mann-Whitney U test (p<0.05). RESULTS: The control group showed the highest prevalence of microorganisms in all sites evaluated. Gram-positive cocci, bacilli and filaments were the most frequent morphotypes. Similar microbial distribution patterns in the RCS and areas of cementum resorption were observed in all groups (p>0.05). The percentage of RCS sites containing microorganisms in groups 1, 2, 3, 4 and control were: 67.6%, 62.5%, 78.2%, 62.0% and 87.6%, respectively. CONCLUSION: In conclusion, the histomicrobiological analysis showed that the rotary instrumentation and the different calcium hydroxide pastes employed did not effectively eliminate the infection from the RCS and periapical lesions. However, several bacteria seen in the histological sections were probably dead or were inactivated by the biomechanical preparation and calcium hydroxide-based intracanal dressing.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Os tumores malignos do canal anal e do anus são muito raros, não ultrapassam 2% de todos os tumores do colo, reto e anus; segundo os principais levantamentos os melanomas não ultrapassam a incidência de 0,1 a 1,2% dos tumores malignos. Os autores descrevem 2 casos de melanoma, discutindo os principais dados da literatura, enfocando os aspectos diagnósticos, tratamento, evolução e prognostico. Os indicies de cura s são baixos e com elevados índices de mortalidade a curto prazo.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The major concern in the therapeutics of tooth replantation refers to the occurrence of root resorption and different approaches have been proposed to prevent or treat these complications. The purpose of this study was to evaluate tissue response to delayed replantation of anterior rat teeth treated endodontically using calcium hydroxide, Sealapex, and Endofill without the placement of gutta-percha cones. Thirty rats had their right upper incisor extracted and maintained in dry storage for 60 min. After removal of the dental papilla, enamel organ, pulp tissue, and periodontal ligament remnants, the teeth were immersed in 2% sodium fluoride phosphate acidulated, pH 5.5, for 10 min. The root canals were dried with absorbent paper points and the teeth were assigned to three groups (n = 10) according to the filling material. Group I - calcium hydroxide and propyleneglycol paste, Group II - Sealapex, and Group III - Endofill. The sockets were irrigated with saline and the teeth were replanted. Replacement resorption, inflammatory resorption and ankylosis were observed in all groups. Although the occurrence of inflammatory resorption was less frequent in Group I, there were no statistically significant differences among the groups. It may be concluded that compared to the paste, filling the root canals with Sealapex and Endofill sealers without the placement of gutta-percha cones did not provide better results.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The purpose of this study was to investigate the influence of the type of vehicle (distilled water or propyleneglycol) on the response of apical tissues of dogs' teeth after root canal filling with mineral trioxide aggregate (MTA) at two different limits. Forty roots of incisors and premolars of two adult dogs were used. After pulpectomy, the root canals were prepared biomechanically, and the roots had the apical cemental barrier penetrated with a #15 K-file and widened to a #25 K-file. The root canals were assigned to four groups according to the vehicle used for MTA (ProRoot-MTA; Tulsa Dental, Tulsa, OK) preparation and the limit of root canal filling: group 1, filling with MTA/distilled water to the limit of the cemental canal; group 2, overfilling with MTA/distilled water, group 3, filling with MTA/propyleneglycol to the limit of the cemental canal; and group 4, overfilling with MTAlpropyleneglycol. The animals were killed by anesthetic overdose 90 days after endodontic treatment and the anatomic pieces were prepared for histomorphological analysis. The sections were stained with hematoxylin and eosin and Brown and Brenn techniques. The results showed that MTA pastes prepared with either distilled water or propyleneglycol as vehicles had similar biological behavior (p > 0.05); root fillings placed at the cemental canal limit showed better results than the overfillings (p = 0.01), and MTA/propyleneglycol paste was more easily placed into the root canals than MTA/distilled water paste.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Objective: This study evaluated the response of periapical tissues to the endodontic sealer Endomethasone in root canal fillings short of or beyond the apical foramen. Material and Methods: Twenty root canals of premolars and incisors of 2 mongrel dogs were used. After coronal access and pulp extirpation, the canals were instrumented up to a size 55 K-file and the apical cemental barrier was penetrated with a size 15 K-file to obtain a main apical foramen, which was widened to a size 25 K-file. The canals were irrigated with saline at each change of file. The root canals were obturated either short of or beyond the apical foramen by the lateral condensation of gutta-percha and Endomethasone, originating 2 experimental groups: G1: Endomethasone/short of the apical foramen; G2: Endomethasone/beyond the apical foramen. The animals were killed by anesthetic overdose 90 days after endodontic treatment. The individual roots were obtained and serial histological sections were prepared for histomorphological analysis (H&E and Brown & Brenn techniques) under light microscopy. The following parameters were examined: closure of the apical foramen of the main root canal and apical opening of accessory canals, apical cementum resorption, intensity of the inflammatory infiltrate, presence of giant cells and thickness and organization of the apical periodontal ligament. Each parameter was scored 1 to 4, 1 being the best result and 4 the worst. Data were analyzed statistically by the Wilcoxon nonparametric tests (p=0.05). Results: Comparing the 2 groups, the best result (p<0.05) was obtained with root canal filling with Endomethasone short of the apical foramen but a chronic inflammatory infiltrate was present in all specimens. Conclusions: Limiting the filling material to the root canal space apically is important to determine the best treatment outcome when Endomethasone is used as sealer.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This study evaluated the response of periapical tissues to the endodontic sealer EndoREZ in root canal fillings short of or beyond the apical foramenlike communication. Twenty root canals of premolars and incisors of 2 mongrel dogs were used. After coronal access and pulp extirpation, the canals were instrumented up to a size 55 K-file and the apical cemental barrier was penetrated with a size 15 K-file to create an apical foramenlike communication, which was widened to a size 25 K-file. The canals were irrigated with saline at each change of file. The root canals were obturated either short of or beyond the apical foramenlike opening by the lateral condensation of gutta-percha and EndoREZ, originating 2 experimental groups: G1, EndoREZ/short of the apical foramenlike opening, and G2, EndoREZ/beyond the apical foramenlike opening. The animals were killed by anesthetic overdose 90 days after endodontic treatment. The individual roots were obtained and serial histological sections were prepared for histomorphological analysis (H&E and Brown and Brenn techniques) under light microscopy. The following parameters were examined: closure of the apical foramenlike communication and apical opening of accessory canals, apical cementum resorptions, intensity of the inflammatory infiltrate, presence of giant cells, and thickness and organization of the apical periodontal ligament. Each parameter was scored 1 to 4, 1 being the best result and 4 the worst. Data were analyzed statistically by the Wilcoxon nonparametric tests (P = .05). Comparing the 2 groups, the best result (P = .05) was obtained with root canal filling with EndoREZ short of the apical foramenlike opening. In conclusion, limiting the filling material to the root canal space apically was important to determine the best treatment outcome when EndoREZ was used as the sealer. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109: e94-e99)

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The purpose of this study was to compare the reaction of rat subcutaneous connective tissue to 0.9% sterile saline, 2.5% sodium hypochlorite (NaOCl), 5.25% NaOCl and 2% chlorhexidine gluconate solution or gel. Six circles were demarcated on the dorsal skin of 24 male Wistar rats, leaving 2 cm between each circle. Using a syringe, 0.1 mL of each root canal irrigant was injected subcutaneously into 5 circles. In the 6th circle, the needle of an empty syringe was introduced into the skin, but no irrigant was injected (control group). Evaluations were undertaken at 2 h, 48 h, 14 days and 30 days post-procedure. Tissue samples were excised, embedded in paraffin blocks and 3-mu m-thick sections were obtained and stained with hematoxylin and eosin. The areas of inflammatory reaction were evaluated and analyzed statistically by ANOVA and Tukey's test. The control group showed few or no inflammatory reaction areas in the subcutaneous tissue. 0.9% saline solution, 2.0% chlorhexidine solution and 2.5% NaOCl showed a good biocompatibility, as very mild inflammatory reaction was detected at 14 days and tissue repair occurred at 30 days. 5.25% NaOCl was the most toxic irrigant, as the number of inflammatory cells remained elevated at 14 and 30 days. The group treated with 2.0% chlorhexidine gluconate gel presented a moderate inflammatory response at 14 days, which decreased at 30 days, being considered similar to that of the control group, 0.9% saline solution, 2.0% chlorhexidine solution and 2.5% NaOCl at this experimental period.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Objective: To evaluate 2 techniques for the treatment of human primary molars with necrotic Pulp and bifurcation bone loss by means of radiographic examination for 48 months. Method and Materials: Fifty-one mandibular primary molars were evaluated in children ranging from 4.5 to 6.5 years of age. The teeth with necrotic pulp and bifurcation bone loss were diagnosed by radiographic examination. The teeth were divided into 2 groups: group 1 (28 teeth)-pulpotomy technique using formocresol as a temporary dressing between sessions and coronal chamber obturation with zinc oxide-eugenol cement; and group 2 (23 teeth)-pulpectomy technique with calcium hydroxide paste as a temporary dressing between sessions and root canal obturation with a dense Calcium hydroxide paste. Standardized radiographs were taken immediately after the fillings were completed and after 12, 24, 36, and 48 months. The radiographs were digitized and analyzed with software that outlined and measured the bifurcation radiolucency. Results: Bifurcation radiolucency reduced significantly or repaired completely for both treatnients in the first 12 months. Minor radiographic reduction of the lesion was observed from 12 to 24 months, and no significant reduction of the remaining radioulcent area was observed from 24 to 48 months after treatment. Conclusion: The 2 endodontic techniques evaluated showed similar results. The main effect of treatment on the lesion repair was obtained in the first year after treatment.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The aim of this study was to evaluate the intraexaminer agreement in the detection of the mandibular canal roof (MCR) and mental foramen (MF) in panoramic radiographs. Forty panoramic radiographs of edentulous patients were used. Two calibrated examiners (A and B) read the images 2 times, for both sides independently, under blind conditions. The interval between the readings was 10 days. The intraexaminer agreement in the interpretation of MCR and MF was performed by kappa statistics with linear weighting (x). The intraexaminer agreement for the detection of MCR, in the left side, was good for both examiners (A: kappa = 0.67; B: kappa = 0.71). Related to the right side, it was found to be kappa = 0.47 and kappa = 0.62, respectively to A and B. The intraexaminer agreement for the detection of MF was good for both examiners interpreting the left side (A: kappa = 0.61; B: kappa = 0.63), and in relation to the right side, it was moderate (A: kappa = 0.51) and fair (B: kappa = 0.38). The intraexaminer agreement in the detection of MCR was good and from good to fair in the detection of MF.