Evidence supporting a protective role for Th9 and Th22 cytokines in human and experimental periapical lesions

Introduction: The development of periapical granulomas is dependent on the host response and involves Th1, Th2, Th17, and Treg-related cytokines. The discovery of new Th9 and Th22 subsets, with important immunomodulatory roles mediated by interleukin (IL)-9 and IL-22, respectively, emphasizes the need for reevaluation of current cytokine paradigms in context of periapical lesions. We investigated the expression of IL-9 and IL-22 in active and stable human granulomas and throughout experimental lesion development in mice. Methods: Periapical granulomas (N = 83) and control specimens (N = 24) were evaluated regarding the expression of IL-9 and IL-22 via realtime polymerase chain reaction. Experimental periapical lesions were induced in mice (pulp exposure and bacterial inoculation) and the lesions evolution correlation with IL-9 and IL-22 expression kinetics was evaluated. Results: IL-9 and IL-22 mRNA expression was higher in periapical lesions than in control samples; higher levels of IL-9 and IL-22 were observed in inactive than in active lesions. In the experimental lesions model, increasing levels of IL-9 and IL-22 mRNA were detected in the lesions, and inverse correlations were found between IL-9 and IL-22 and the increase of lesion area in the different time point intervals. Conclusions: Our results suggest that Th9 and Th22 pathways may contribute to human and experimental periapical lesion stability

Periapical Tissue Response After Use of Intermediate Restorative Material, Gutta-Percha, Reinforced Zinc Oxide Cement, and Mineral Trioxide Aggregate as Retrograde Root-End Filling Materials: A Histologic Study in Dogs

Purpose: To investigate the periapical tissue response of 4 different retrograde root-filling materials, ie, intermediate restorative material, thermoplasticized gutta-percha, reinforced zinc oxide cement (Super-EBA), and mineral trioxide aggregate (MTA), in conjunction with an ultrasonic root-end preparation technique in an animal model. Materials and Methods: Vital roots of the third and fourth right mandibular premolars in 6 healthy mongrel dogs were apicectomized and sealed with 1 of the materials using a standardized surgical procedure. After 120 days, the animals were sacrificed and the specimens were analyzed radiologically, histologically, and scanning electron microscopically. The Fisher exact test was performed on the 2 outcome values. Results: Twenty-three sections were analyzed histologically. Evaluation showed better re-establishment of the periapical tissues and generally lower inflammatory infiltration in the sections from teeth treated with the intermediate restorative material and the MTA. New root cement on the resected dentin surfaces was seen on all sections regardless of the used material. New hard tissue formation, directly on the surface of the material, was seen only in the MTA sections. There was no statistical difference in outcome among the tested materials. Conclusions: The results from this dog model favor the intermediate restorative material and MTA as retrograde fillings when evaluating the bone defect regeneration. MTA has the most favorable periapical tissue response when comparing the biocompatibility of the materials tested. (C) 2012 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 70:2041-2047, 2012

Capsule Locus Polymorphism among Distinct Lineages of Enterococcus faecalis Isolated from Canals of Root-filled Teeth with Periapical Lesions

Introduction: Although Enterococcus faecalis is a member of the normal microbiota, it is also a major cause of nosocomial infections. Some strains of E. faecalis produce capsule, which contributes to pathogenesis through evasion of host defenses, and its production is dependent on the capsule (cps) operon polymorphism. This study investigated cps locus polymorphism in distinct lineages of E. faecalis isolated from canals of root-filled teeth with periapical lesions. Methods: Twenty-two E. faecalis isolates were evaluated regarding the cps operon polymorphism and genetic diversity. The 3 known CPS types were determined by polymerase chain reaction. This information was correlated with multilocus sequence typing data, which were used to define genetic lineages. Results: cpsA and cpsB were the only detected genes within the cps operon in 62.5% of E. faecalis strains (14/22), indicative of genotype CPS 1, which lacks capsule expression. The essential genes in the cps operon for capsule production were detected in the remaining strains, whereas 3 belonged to genotype CPS 5 and 5 strains to genotype CPS 2. A total of 14 sequence types (STs) were resolved in 22 E. faecalis isolates. Comparison with the E. faecalis international multilocus sequence typing database revealed that 9 STs were previously found, and that the 5 STs were novel. Conclusions: Certain E. faecalis genotypes from canals of root-filled teeth with periapical lesions belong to lineages associated with capsule expression and production of multiple virulence factors, which might account for their increased pathogenic potential. (J Endod 2012;38:58-61)

Comparative study of cone beam computed tomography and intraoral periapical radiographs in diagnosis of lingual-simulated external root resorptions

Background: Owing to a lack of symptoms and difficult visualization in routine intraoral radiographs, diagnosis of external root resorptions can be challenging. Aim: The goal of this study was to compare two image acquisition methods, intraoral radiographs and cone beam computed tomography (CBCT), in the diagnosis of external resorption. Material and Methods: Thirty-four maxillary and mandibular bicuspids were divided into three groups. Perforations measuring 0.3 and 0.6 mm in diameter and 0.15 and 0.3 mm in depth, respectively, were made on the lingual root surfaces in thirty teeth, and four were used as controls. Next, teeth were mounted on an apparatus and radiographed at mesial, distal, and orthoradial angulations. CBCT images were also taken. The analysis of the intraoral radiographic and tomographic images was carried out by two experts using standardized scores. Data were then compared statistically. Results: A strong agreement between the examiners was observed in both diagnosis methods, the intraoral radiographic (r = 0.93) and the tomographic analysis (r = 1.0). Tomography had higher statistically significant detection values than intraoral radiography (P < 0.05). In intraoral radiographs, the detection was significantly greater (P < 0.05) in the mandibular bicuspids, compared with their maxillary counterparts. The ability to detect 0.6-mm perforations by intraoral radiography was significantly higher than that of 0.3-mm perforations (P < 0.05). Conclusion: Cone beam computed tomography showed better diagnostic ability compared with intraoral radiography, regardless of the tooth or the dimensions of the resorption evaluated.

Toll-like Receptor 2 Knockout Mice Showed Increased Periapical Lesion Size and Osteoclast Number

Introduction: The aim of this study was to characterize the formation and progression of experimentally induced periapical lesions in TLR2 knockout (TLR2 KO) mice. Methods: Periapical lesions were induced in molars of 28 wild type (WT) and 27 TLR2 KO mice. After 7, 21, and 42 days, the animals were euthanized, and the mandibles were subjected to histotechnical processing. Hematoxylin-eosin-stained sections were examined under conventional light microscopy for the description of pulpal, apical, and periapical features and under fluorescence microscopy for the determination of the periapical lesion size. The subsequent sections were evaluated by tartrate resistant acid phosphatase histoenzymology (osteoclasts), Brown and Brenn staining (bacteria), and immunohistochemistry (RANK, RANKL, and OPG). Data were analyzed by the Mann-Whitney U and Kruskal-Wallis tests (alpha = 0.05), Results: The WT group showed significant differences (P < .05) in the periapical lesion size and the osteoclast number between 7 and 42 days and between 21 and 42 days. In the TLR2 KO group, significant differences (P < .05) in the periapical lesion size and the osteoclast number were found between 7 days and the other periods. There was a significant difference (P < .05) between the 2 types of animal regarding the periapical lesion size, which was larger in the TLR2 KO animals. No significant differences (P > .05) were found between WT and TLR2 KO mice related to the pulpal, apical, and periapical features; bacteria localization; and immunohistochemical results (except for RANK expression). Conclusions: TLR2 KO animals developed larger periapical lesions with a greater number of osteoclasts, indicating the important role of this receptor in the host's immune and inflammatory response to root canal and periradicular infection. (J Endod 2012;38:803-813)

Expression Analysis of Wound Healing Genes in Human Periapical Granulomas of Progressive and Stable Nature

Introduction: Wound healing process involves the activation of extracellular matrix components, remodeling enzymes, cellular adhesion molecules, growth factors, cytokines and chemokines genes. However, the molecular patterns underlying the healing process periapical environment remain unclear. Here we hypothesized that endodontic infection might result in an imbalance in the expression of wound healing genes involved in the pathogenesis of periapical lesions. Furthermore, we suggest that differential expression of wound healing markers in active and latent granulomas could account for different clinical outcomes for such lesions. Methods: Study samples consisted of 93 periapical granulomas collected after endodontic surgeries and 24 healthy periodontal ligament tissues collected from premolars extracted for orthodontic purposes as control samples. Of these, 10 periapical granulomas and 5 healthy periapical tissues were used for expression analysis of 84 wound healing genes by using a pathway-specific real-time polymerase chain reaction array. The remaining 83 granulomas and all 24 control specimens were used to validate the obtained array data by real-time polymerase chain reaction. Observed variations in expression of wound healing genes were analyzed according to the classification of periapical granulomas as active/progressive versus inactive/stable (as determined by receptor activator for nuclear factor kappa B ligand/osteoprotegerin expression ratio). Results: We observed a marked increase of 5-fold or greater in SERPINE1, TIMP1, COL1A1, COL5A1, VTN, CTGF, FGF7, TGFB1, TNF, CXCL11, ITGA4, and ITGA5 genes in the periapical granulomas when compared with control samples. SERPINE1, TIMP1, COL1A1, TGFB1, and ITGA4 mRNA expression was significantly higher in inactive compared with active periapical granulomas (P < .001), whereas TNF and CXCL11 mRNA expression was higher in active lesions (P < .001). Conclusions: The identification of novel gene targets that curb the progression status of periapical lesions might contribute to a more accurate diagnosis and lead to treatment modalities more conducive to endodontic success. (J Endod 2012;38:185-190)

Central giant cell granuloma

Background: Central giant cell granuloma is a benign condition of the jaws which may present an aggressive behavior. Case report: A 9-year-old boy was complaining of swelling in the floor of the mouth. A solid swelling was observed in the area of the lower incisors. From the radiographic exam, we observed a radiolucent image in the mandibular bone with well-defined limits extending from the apical region of tooth 33 to the apical region of tooth 42. Discussion: Due to the diagnosis and the age of the patient, we chose a conservative treatment, administering subcutaneous injections of calcitonin. During this treatment, no reduction to the lesion was observed. Therefore, we chose to treat the lesion with triamcinolone acetonide. Monthly follow-ups demonstrated good lesion reduction and the absence of any clinical symptoms during the first 2 years. After a 3-year follow-up, the patient returned, presenting mobility of the lower incisors. A significant increase in the size of the lesion was observed. After a biopsy, with the removal of tissuewhich had the appearance of a cyst capsule, microscopic analyses were found to be compatible with a secondarily infected cyst. Two months following this procedure, the patient did not present tooth mobility anymore and the oral mucosa presented a normal aspect. Following a radiographic exam, full lesion repair was observed. These conservative treatments should be the first option in cases of central giant cell granuloma and the patient must be observed for a long period of time, until no further clinical or radiographic signs of lesions are observed

Healing of a tooth with an overinstrumented apex, extensive transportation and periapical lesion using a 5 mm calcium hydroxide apical plug: an 8-year follow-up report

Besides the risk of filling material extrusion throughout the apex, a satisfactory apical seal can be difficult to achieve in canals with open apices or iatrogenic enlargements of the apical constriction. These situations pose a challenge to root canal filling. This paper describes the root canal filling of a maxillary right canine with an overinstrumented apex, complete loss of the apical stop, extensive canal transportation and apical periodontitis. A 5 mm calcium hydroxide apical plug was placed before root canal filling. The plug was made by soaking paper points with saline, dipping the points in calcium hydroxide powder and then applying it to the apex several times, until a consistent apical plug was obtained. The canal was then irrigated with saline in order to remove any residual calcium hydroxide from the root canal walls, dried with paper points and obturated with an inverted #80 gutta-percha cone and zinc oxide-eugenol based sealer by the lateral condensation technique. An 8-year radiographic follow-up showed formation of mineralized tissue sealing the apical foramen, apical remodeling and no signs of apical periodontitis.

Displasia cementária periapical: relato de dois casos

A displasia cementária periapical (DCP) é considerada uma alteração pseudotumoral de etiologia desconhecida. Essa patologia é assintomática e tem crescimento autolimitante. Os dentes afetados apresentam normalmente vitalidade pulpar e integridade da lâmina dura. Objetivo: Apresentar dois casos clínicos que demonstram a importância do conhecimento e correto diagnóstico da DCP. Relatos clínicos: Paciente M.I.S, de 61 Anos, Gênero Feminino, Leucoderma. Apresentou-se ao setor de Endodontia, para avaliação, ao exame radiográfico foi constatada imagem radiopaca nos ápices de incisivos inferiores. Ao teste de sensibilidade ao frio houve resposta negativa, então foi realizado o teste em outras áreas da mandíbula, também com resposta negativa, tornando o teste inconclusivo. Com base nas informações obtidas pelos exames clínico e radiográfico, foi diagnosticada a DCP. Realizado controle clínico e radiográfico, não houve alterações significativas. Paciente H.N.P.N, de 22 Anos, Gênero Feminino, Leucoderma. Apresentou-se ao setor de Endodontia, para avaliação, ao exame radiográfico foi constatada imagem radiopaca na região perirradicular de canino e primeiro pré-molar inferiores do lado esquerdo. Ao teste de sensibilidade ao frio, houve resposta positiva. Com base nas informações obtidas pelos exames clínico e radiográfico, foi diagnosticada a DCP. Realizado controle clínico e radiográfico, não houve alterações significativas. Conclusão: Devido as suas características radiográficas, a DCP pode ser confundida com lesões inflamatórias de origem endodôntica. Intervenções endodônticas desnecessárias podem ocorrer por isso o cirurgião-dentista deve estar atento quanto à vitalidade pulpar e a integridade da lâmina dura dos dentes envolvidos, para o correto diagnóstico.

Pro-inflammatory effects of the aqueous extract of Echinometra lucunter sea urchin spines

The sea urchin, Echinometra lucunter, can be found along the Western Central Atlantic shores. In Brazil, it is responsible by circa 50% of the accidents caused by marine animals. The symptoms usually surpass trauma and may be pathologically varied and last differently, ranging from spontaneous healing in a few days, to painful consequences lasting for weeks. In this work, we have mimicked the sea urchin accident by administering an aqueous extract of the spine into mice and rats and evaluated the pathophysiological developments. Our data clearly indicate that the sea urchin accident is indeed a pro-inflammatory event, triggered by toxins present in the spine that can cause edema and alteration in the leukocyte-endothelial interaction. Moreover, the spine extract was shown to exhibit a hyperalgesic effect. The extract is rich in proteins, as observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but also contains other molecules that can be analyzed by reversed phase high-performance liquid chromatography. Altogether, these effects corroborate that an E. lucunter encounter is an accident and not an incident, as frequently reported by the victims.

The contribution of a murine CNS-TB model for the understanding of the host-pathogen interactions in the formation of granulomas

Central nervous system (CNS) tuberculosis (TB) is the most severe form of TB, characterized morphologically by brain granulomas and tuberculous meningitis (TBM). Experimental strategies for the study of the host-pathogen interaction through the analysis of granulomas and its intrinsic molecular mechanisms could provide new insights into the neuropathology of TB. To verify whether cerebellar mycobacterial infection induces the main features of the disease in human CNS and better understand the physiological mechanisms underlying the disease, we injected bacillus Calmette-Guerin (BCG) into the mouse cerebellum. BCG-induced CNS-TB is characterized by the formation of granulomas and TBM, a build up of bacterial loads in these lesions, and microglial recruitment into the lesion sites. In addition, there is an enhanced expression of signaling molecules such as nuclear factor-kappa B (NF-kappa B) and there is a presence of inducible nitric oxide synthase (iNOS) in the lesions and surrounding areas. This murine model of cerebellar CNS-TB was characterized by cellular and biochemical immune responses typically found in the human disease. This model could expand our knowledge about granulomas in TB infection of the cerebellum, and help characterize the physiological mechanisms involved with the progression of this serious illness that is responsible for killing millions people every year. (C) 2012 Elsevier B.V. All rights reserved.

In vitro and in vivo evaluation of the biocompatibility of a calcium phosphate/poly(lactic-co-glycolic acid) composite

This study assess the effects of bioceramic and poly(lactic-co-glycolic acid) composite (BCP/PLGA) on the viability of cultured macrophages and human dental pulp fibroblasts, and we sought to elucidate the temporal profile of the reaction of pulp capping with a composite of bioceramic of calcium phosphate and biodegradable polymer in the progression of delayed dentine bridge after (30 and 60 days) in vivo. Histological evaluation of inflammatory infiltrate and dentin bridge formation were performed after 30 and 60 days. There was similar progressive fibroblast growth in all groups and the macrophages showed viability. The in vivo study showed that of the three experimental groups: BCP/PLGA composite, BCP and calcium hydroxide (Ca(OH)(2)) dentin bridging was the most prevalent (90 %) in the BCP/PLGA composite after 30 days, mild to moderate inflammatory response was present throughout the pulp after 30 days. After 60 days was observed dentine bridging in 60 % and necrosis in 40 %, in both groups. The results indicate that understanding BCP/PLGA composite is biocompatible and by the best tissue response as compared to calcium hydroxide in direct pulp capping may be important in the mechanism of delayed dentine bridge after 30 and 60 days.

Treatment of central giant cell lesions using bisphosphonates with intralesional corticosteroid injections

Central giant cell lesions are benign intraosseous proliferative lesions that have considerable local aggressiveness. Nonsurgical treatment methods, such as intralesional corticosteroid injections, systemic calcitonin and interferon have been reported. Recently, bisphosphonates have been used to treat central giant cell lesions. A case of a 36-year-old male with a central giant cell lesion crossing the mandibular midline was treated with intralesional corticosteroids combined with alendronate sodium for the control of systemic bone resorption. The steroid injections and the use of bisphosphonates were stopped after seven months when further needle penetration into the lesion was not possible due to new bone formation. After two years, the bony architecture was near normal, and only minimal radiolucency was present around the root apices of the involved teeth. The patient was followed up for four years, and panoramic radiography showed areas of new bone formation. Thus far, neither recurrence nor side effects of the medication have been detected.

Association analysis of clinical aspects and vitamin D receptor gene polymorphism with external apical root resorption in orthodontic patients

Introduction: Vitamin D is responsible for the regulation of certain genes at the transcription level, via interaction with the vitamin D receptor, and influences host immune responses and aspects of bone development, growth, and homeostasis. Our aim was to investigate the association of TaqI vitamin D receptor gene polymorphism with external apical root resorption during orthodontic treatment. Methods: Our subjects were 377 patients with Class II Division 1 malocclusion, divided into 3 groups: (1) 160 with external apical root resorption <= 1.43 mm, (2) 179 with external apical root resorption >1.43 mm), and (3) 38 untreated subjects. External apical root resorption of the maxillary incisors was evaluated on periapical radiographs taken before and after 6 months of treatment. After DNA collection and purification, vitamin D receptor TaqI polymorphism analysis was performed by polymerase chain reaction-restriction fragment length polymorphism. Univariate and multivariate analyses were performed to verify the association of clinical and genetic variables with external apical root resorption (P <0.05). Results: There was a higher proportion of external apical root resorption in orthodontically treated patients compared with the untreated subjects. In patients orthodontically treated, age higher than 14 years old, initial size of the maxillary incisor root superior to 30 mm, and premolar extraction were associated with increased external apical root resorption. Genotypes containing the C allele were weakly associated with protection against external apical root resorption (CC + CT x TT [odds ratio, 0.29; 95% confidence interval, 0.07-1.23; P = 0.091]) when treated orthodontic patients were compared to untreated individuals. Conclusions: Clinical factors and vitamin D receptor TaqI polymorphism were associated with external apical root resorption in orthodontic patients. (Am J Orthod Dentofacial Orthop 2012; 142: 339-47)

Treatment of severe forms of paracoccidioidomycosis: is there a role for corticosteroids?

Despite their immunosuppressive effects, corticosteroids have long been used as adjunct therapy (aCST) in the treatment of infectious diseases. The rationale is that in certain infections it is necessary to decrease the exacerbated host's inflammatory response, which can otherwise result in tissue damage and organ dysfunction. In fact, a major concern in treating paracoccidioidomycosis (PCM) is the host's intense inflammatory response to Paracoccidioides brasiliensis, which can be further intensified by antifungal therapy. Depending on its localization, this immunological phenomenon may be life threatening or result in permanent sequels, as is the case for some patients with cerebral or laryngeal involvement. However, the literature on aCST in paracoccidioidomycosis treatment is scarce and as a result we present our recent experience in the management of four patients with severe PCM manifestations, i.e., cerebral paracoccidioidal granuloma, laryngeal stenosis, compressive abdominal mass, and exacerbated inflammatory response with tissue destruction. In addition to the antifungal therapy, these patients required aCST, which probably promoted their clinical improvement and/or prevented serious complications. We suggest that aCST: (a) can potentially help in the management of selected cases of severe forms of PCM, particularly when there is a risk of acute complications, and (b) that it can be used safely provided that the risk-benefit ratio is carefully weighed. Well-controlled, prospective studies of aCST in the treatment of severe cases of paracoccidioidomycosis are needed to better define its role in the management of PCM.