Osteopontin involvement in granuloma formation and in the severity of Paracoccidioides brasiliensis infection

The participation of osteopontin (OPN) in Paracoccidioides brasiliensis infected mice, its association to granulomatogenesis, severity of infection, pattern of lesions, nitric oxide (NO) levels and fungal load were evaluated in this investigation. Immunohistochemistry analysis showed marked OPN staining in extracellular matrix and in macrophages and multinucleated giant cells at the center of lesions, suggesting a possible role of OPN in the distribution of these cells within the granulomas. At 15 days post-infection with a virulent P. brasiliensis isolate, OPN(+) cells were more numerous and intensely immunostained in the loose granulomas of susceptible mice than in those of resistant mice. In addition, high fungal loads and low NO levels were observed in susceptible mice. At 120 days after infection, resistant mice had increased total OPN levels (ELISA) and OPN positivity in compact granulomas, higher NO levels and lower fungal loads than susceptible mice. Residual lesions associated with low OPN levels, high NO and control of fungal dissemination were observed in both mouse strains at 120 days post-infection with the slightly virulent fungal isolate. Therefore, OPN could be associated with higher severity of the disease in an early phase of infection and with a degree of control of the progressive infection.

CCR2 Deficiency Results in Increased Osteolysis in Experimental Periapical Lesions in Mice

Introduction: Periapical lesions are chronic inflammatory disorders of periradicular tissues caused by etiologic agents of endodontic origin. The inflammatory chemokines are thought to be involved in the latter observed osteolysis. With a murine model of experimental periapical lesion, the objective of this study was to evaluate the role of the chemokine receptor CCR2 in the lesion progression, osteoclast differentiation and activation, and expression of inflammatory osteolysis-related mediators. Methods: For lesion induction, right mandibular first molars were opened surgically with a (1)/(4) carbine bur, and 4 bacterial strains were inoculated in the exposed dental pulp; left mandibular first molars were used as controls. Animals were killed at 3, 7, 14, and 21 days after surgeries to evaluate the kinetics of lesion development. Results: CCR2 KO mice showed wider lesions than WT mice. CCR2 KO mice also expressed higher levels of the osteoclastogenic and osteolytic factors, receptor activator of nuclear factor kappa B ligand (RANKL) and cathepsin K, of the proinflammatory cytokine tumor necrosis factor alpha, and of the neutrophil migration related chemokine, KC. Conclusions: These results suggest that CCR2 is important in host protection to periapical osteolysis. (J Endod 2010;36:244-250)

Oral foreign body granuloma: unusual presentation of a rare adverse reaction to permanent injectable cosmetic filler

COSTA MIGUEL, M. C.; NONAKA, C. F. W.; GERMANO, A. R.; SOUZA, L. B.; SOUZA, L. B. Oral foreign body granuloma: unusual presentation of a rare adverse reaction to permanent injectable cosmetic filler. International journal of oral and maxillofacial surgery, v. 38, p. 385-387, 2009.

Epidemiology, clinical signs, histopathology and molecular characterization of canine leproid granuloma: a retrospective study of cases from Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of calcium hydroxide-based materials on periapical tissue healing and orthodontic root resorption of endodontically treated teeth in dogs

This study evaluated periapical tissue healing and orthodontic root resorption of endodontically treated teeth sealed with calcium hydroxide in dogs. The sample consisted of three contralateral pairs of maxillary incisors and two contralateral pairs of mandibular incisors in each of two dogs using a split mouth design. After biomechanical preparation of the teeth in the first group (n = 10), a Ca(OH)(2) dressing was placed for 14 days before root canal filling with Ca(OH)(2)-based sealer (Sealapex) and gutta-percha points. In the second group (n = 10), root canals were obturated immediately after the mechanical preparation with gutta-percha points and zinc oxide and eugenol (ZOE)-based sealer (Endofill). After completion of endodontic treatment, the teeth were moved with an orthodontic appliance with a calibrated force of 200 g, reactivated every 21 days. After 105 days, the animals were killed and the teeth were removed upon completion of active treatment, without a period of recovery, and prepared for histomorphological analysis. All sections of each tooth were graded subjectively on a scale from one to four to obtain the average of the 16 histomorphological parameters analysed. Evaluation of the differences between the two treatment protocols was made with Mann-Whitney U-test. It was observed that the teeth treated with Ca(OH)(2)-based materials provided better outcomes (P = 5%), with complete repair of all root resorption areas, high rate of biological closure of the main canal and apical accessory canals by newly formed cementum, less intense and extensive chronic inflammatory infiltrate, and better organization of the periodontal ligament. Under the tested conditions, Ca(OH)(2)-based materials had a favourable action on periapical tissue healing and repair of orthodontic root resorption in endodontically treated dogs' teeth.

Periapical tissue reactions to calcium hydroxide and MTA after external root resorption as a sequela of delayed tooth replantation

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

Influence of the type of vehicle and limit of obturation on apical and periapical tissue response in dogs' teeth after root canal filling with mineral trioxide aggregate

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.

Influence of apical foramen widening and sealer on the healing of chronic periapical lesions induced in dogs' teeth

Objective. The aim of this study was to evaluate the influence of apical foramen widening on the healing of chronic periapical lesions in dogs' teeth after root canal filling with Sealer 26 or Endomethasone.Study design. Forty root canals of dogs' teeth were used. After pulp extirpation, the canals were exposed to the oral cavity for 180 days for induction of periapical lesions, and then instrumented up to a size 55 K-file at the apical cemental barrier. In 20 roots, the cemental canal was penetrated and widened up to a size 25 K-file; in the other 20 roots, the cemental canal was preserved (no apical foramen widening). All canals received a calcium hydroxide intracanal dressing for 21 days and were filled with gutta-percha and 1 of the 2 sealers: group 1: Sealer 26/apical foramen widening; group 2: Sealer 26/no apical foramen widening; group 3: Endomethasone/apical foramen widening; group 4: Endomethasone/no apical foramen widening. The animals were killed after 180 days, and serial histologic sections from the roots were prepared for histomorphologic analysis. Scores were assigned according to preestablished histomorphologic parameters and analyzed statistically by Kruskal-Wallis and Mann-Whitney U tests.Results. Regarding new cementum formation, repair of cementum and bone resorption areas, presence of microorganisms, inflammatory cell infiltrate and periodontal ligament conditions, significantly better periapical healing was obtained when foramen widening was done and Sealer 26 was used.Conclusion. Apical foramen widening and calcium hydroxide-containing sealer were more favorable to the healing of chronic periapical lesions. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109:932-940)

Patient comfort in periapical examination using digital receptors

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

Antigenic Activity of Bacterial Endodontic Contents from Primary Root Canal Infection with Periapical Lesions against Macrophage in the Release of Interleukin-1 beta and Tumor Necrosis Factor alpha

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

Detection of periapical lesion development by conventional radiography or computed tomography

Objective. The aim of this study was to detect the development of experimentally induced periapical lesions using conventional radiography and computed tomography.Study design. The root canals of dogs' teeth were exposed to the oral environment for 7 days for contamination and then sealed for 7 days (GI), 15 days (GII), 30 days (GIII), and 60 days (GIV). Immediately after each experimental period, radiographs and tomograms were taken in order to detect the occurrence of periapical bone resorption. The periapical radiographs were digitized and areas of bone resorption were measured using the VIXWIN 2000 software. Scores were assigned to the tomograms based on the progression of periapical bone resorption. The specimens were evaluated by calibrated examiners who were blinded to the groups. The radiographic results were analyzed by ANOVA and Tukey's test (P <.05) and the tomographic results were analyzed by Kruskal-Wallis and Dunn's tests (P <.05).Results. The radiographic evaluation did not reveal periapical lesions at the 7-day control. Lesions were radiographically visible at 15 and 30 days (47.4% and 77.8% of the cases, respectively) and presented similar dimensions (P <.05). At 60 days, lesions were detected in all specimens, presenting larger dimensions than those of the earlier evaluation periods (P <.05). The tomographic evaluation detected lesions at 7 and 15 days (32.5% and 83.3% of the cases, respectively). Lesions were detected in all specimens at the 30- and 60-day periods, when the greatest values of bone resorption were observed (P <.05).Conclusions. Tomography was able to detect periapical lesion development in its initial stages, even when the lesions were undetectable radiographically.

Comparative radiographic and histological analyses of periapical lesion development

Objective. The present study evaluated the dynamics of the development of periapical lesions.Study design. Root canals from dogs' teeth were exposed to the oral environment, and then sealed for 7 days (Group A), 15 days (Group B), 30 days (Group C), and 60 days (Group D). After each experimental period, radiographs were taken to detect periapical bone resorption. In addition, histological sections from the periapical region were prepared. The radiographic and histological results were analyzed by ANOVA and Tukey's, Wilcoxon, and Pearson's tests. Significance level was set at 5%.Results. Lesions were radiographically visible at 15 and 30 days, and had similar size at these periods (P > .05). At 60 days, lesions were larger than in the other periods (P < .05). Bone resorption was detected histologically at 7 days. The greatest values of bone resorption were observed at the 30- and 60-day periods (P < .05). The results of the methods of evaluation were similar only at the 30-day period. There was no correlation between the radiographic and histological results.Conclusions. Periapical radiography did not provide detection of periapical lesion in its initial stages. The periapical lesions became more evident radiographically when the bone resorption area increased. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107:442-447)

Evaluation of chronic periapical lesions by digital subtraction radiography by using adobe photoshop CS: A technical report

The purpose of this study was to describe a new technique by using Adobe Photoshop CS (San Jose, CA) image-analysis software to evaluate the radiographic changes of chronic periapical lesions after root canal treatment by digital subtraction radiography. Thirteen upper anterior human teeth with pulp necrosis and radiographic image of chronic periapical lesion were endodontically treated and radiographed 0, 2, 4, and 6 months after root canal treatment by using a film holder. The radiographic films were automatically developed and digitized. The radiographic images taken 0, 2, 4, and 6 months after root canal therapy were submitted to digital subtraction in pairs (0 and 2 months, 2 and 4 months, and 4 and 6 months) choosing image, calculation, subtract, and new document tools from Adobe Photoshop CS image-analysis software toolbar. The resulting images showed areas of periapical healing in all cases. According to this methodology, the healing or expansion of periapical lesions can be evaluated by means of digital subtraction radiography by using Adobe Photoshop CS software.

Er : YAG laser: Antimicrobial effects in the root canals of dogs' teeth with pulp necrosis and chronic periapical lesions

Objective: Our goal in this study was to evaluate the antimicrobial effect of Er:YAG laser applied after biomechanical preparation of the root canals of dog's teeth with apical periodontitis. Background Data: Various in vitro studies have reported effective bacterial reduction in infected root canals using Er:YAG laser. However, there is no in vivo research to support these results. Methods: Forty root canals of dogs' premolar teeth with pulp necrosis and chronic periapical lesions were used. An initial microbiological sample was taken, and after biomechanical preparation was carried out, a second microbiological sample was taken. The teeth were divided into two groups: Group I-biomechanical preparation was taken of root canals without Er:YAG laser application; Group II-biomechanical preparation was taken of root canals with Er:YAG laser application using 140-mj input, 63-mJ output/15 Hz. After coronal sealing, the root canals were left empty for 7 days at which time a third microbiological sample was taken. The collected material was removed from the root canal with a #40 K file and placed in transport media. It was serially diluted and seeded on culture dishes selective for anaerobes, aerobes, and total streptococci. Colony-forming units per milliliter (CFU/mL) were counted. Results: Groups I and II showed an increase of CFU/mL for all microorganisms 7 days after treatment, being statistically significant for anaerobes in Group I and for anaerobes and total streptococci in Group II. When comparing CFU/mL of Groups I and II, there was a statistically significant increase after 7 d for total streptococci in Group II. Conclusion: Er:YAG laser applied after biomechanical preparation did not reduce microorganisms in the root canal system.

A comparison study of periapical repair in dogs' teeth using RoekoSeal and AH plus root canal sealers: A histopathological evaluation

The objective of the study was to evaluate the biocompatibility of RoekoSeal sealer Roeko (Dental Products, Langenau, Germany) with the periapical tissues of dogs and compare it with AH Plus sealer (Dentsply/De Trey, Konstanz, Germany). The pulps of 32 root canals were removed, the apical cementum layer perforated, the biomechanical preparation performed, and the root canals filled by lateral condensation technique. Ninety days after the surgery, the animals were euthanized, the bone with teeth removed, and the samples prepared for histopathological analysis. In group 1 (RoekoSeal Automix), deposition of mineralized tissue was observed, with complete newly mineralized apical formed tissue in 43.8% and partial sealing in 56.2%. In group 2 (AH Plus), in 12.5% there was complete newly mineralized apical formed tissue, in 75% the sealing was partial, and in 12.5% there was no sealing (p < 0.05). There were no differences between the groups in relation to the inflammatory infiltrate; thickness of the periodontal ligament; and the resorption of dentin, cementum or bone (p > 0.05).