Low-level laser therapy as an alternative for pulpotomy in human primary teeth.

This study aimed to evaluate the effects of low-level laser therapy (LLLT) on pulpal response of primary teeth. Twenty mandibular primary molars were randomly divided into the following groups: group I Buckley's formocresol (diluted at 1:5), group II calcium hydroxide, group III LLLT + zinc oxide/eugenol, and group IV LLLT + calcium hydroxide. LLLT parameters were set at 660-nm wavelength, 10-mW power output, and 2.5 J/cm(2) energy density for 10 s in continuous mode (InGaAlP laser, Twin Laser®, MMOptics, Sao Carlos, Sao Paulo, Brazil). The teeth were extracted at the regular exfoliation period. The dentin-pulp complex was graded by an established histopathological score system. Statistical analysis was performed by Kruskal-Wallis and chi-square test. The histopathological assessment revealed statistically significant differences among groups (P < 0.05). The lowest degree of pulpal inflammation was present in LLLT + calcium hydroxide (P = 0.0296). Calcium hydroxide showed the highest rate of hard tissue barrier (P = 0.0033), odontoblastic layer (P = 0.0033), and dense collagen fibers (P = 0.0095). On the other hand, formocresol showed the highest incidence of internal resorption (P = 0.0142). Based on this study, low-level laser therapy preceding the use of calcium hydroxide exhibited satisfactory results on pulp tissue healing. However, further clinical studies on human teeth with long-term follow-up are needed to test the low-level laser therapy efficacy.

Mesenchymal stem cells as active prohealing and immunosuppressive agents in periapical environment: evidence from human and experimental periapical lesions.

INTRODUCTION: Previous studies describe contrasting molecular profiles of active and inactive periapical granulomas characterized by distinct expression of cytokines, osteoclastogenic factors, and wound healing markers. Although the molecular mechanisms underlying such a dichotomy remain unknown, in this study we investigated the potential involvement of mesenchymal stem cells (MSCs) in determining human and murine periapical lesion activity and outcomes. METHODS: Periapical granulomas (n = 83) and control samples (n = 24) were comparatively assessed for the expression levels of 11 mesenchymal stem cell (MSC) markers using real-time polymerase chain reaction. Experimental periapical lesions induced in mice were evaluated for MSC marker expression and the effects of AMD3100 treatment on lesion outcomes. RESULTS: MCS marker expression was prevalent in periapical granulomas compared with that in controls, whereas CD29, CD73, CD90, CD146, CD166, NANOG, Stro-1, and CXCR4 expressions were higher in inactive than in active lesions. Experimental periapical lesion inactivity was also associated with an increased expression of MSC markers. The inhibition of MSC mobilization to the periapex by AMD3100 resulted in increased lesion sizes; decreased expression of MSCs and wound healing markers; and increased expression of interleukin 1 beta (IL-17ß), interleukin 17 (IL-17), tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), and nuclear factor kappa-B ligand (RANKL). CONCLUSIONS: Our results show that MSC markers are overexpressed in inactive human and experimental periapical lesions and that MSC mobilization results in the attenuation of experimental lesion progression associated with immunosuppressive and prohealing mechanisms.

Rat subcutaneous tissue response to MTA Fillapex® and Portland cement.

The aim of this study was to evaluate the response of rat subcutaneous tissue to MTA Fillapex® (Angelus), an experimental root canal filling material based on Portland cement and propylene glycol (PCPG), and a zinc oxide, eugenol and iodoform (ZOEI) paste. These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Wistar rats for 7 and 15 days. The specimens were stained with hematoxylin and eosin, and evaluated regarding inflammatory reaction parameters by optical microscopy. The intensity of inflammatory response against the sealers was analyzed by two blinded and previously calibrated examiners for all experimental periods (kappa=0.96). The histological evaluation showed that all materials caused a moderate inflammatory reaction at 7 days, which subsided with time. A greater inflammatory reaction was observed at 7 days in the tubes filled with ZOEI paste. Tubes filled with MTA Fillapex presented some giant cells, macrophages and lymphocytes after 7 days. At 15 days, the presence of fibroblasts and collagen fibers was observed indicating normal tissue healing. The tubes filled with PCPG showed similar results to those observed in MTA Fillapex. At 15 days, the inflammatory reaction was almost absent at the tissue, with several collagen fibers indicating normal tissue healing. Data were analyzed by the nonparametric Kruskal-Wallis test (α=0.05). Statistically significant difference (p<0.05) was found only between PCPG at 15 days and ZOEI at 7 days groups. No significant differences were observed among the other groups/periods (p>0.05). MTA Fillapex and Portland cement added with propylene glycol had greater tissue compatibility than the PCPG paste.

Rat subcutaneous tissue response to MTA Fillapex® and Portland cement

The aim of this study was to evaluate the response of rat subcutaneous tissue to MTA Fillapex® (Angelus), an experimental root canal filling material based on Portland cement and propylene glycol (PCPG), and a zinc oxide, eugenol and iodoform (ZOEI) paste. These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Wistar rats for 7 and 15 days. The specimens were stained with hematoxylin and eosin, and evaluated regarding inflammatory reaction parameters by optical microscopy. The intensity of inflammatory response against the sealers was analyzed by two blinded and previously calibrated examiners for all experimental periods (kappa=0.96). The histological evaluation showed that all materials caused a moderate inflammatory reaction at 7 days, which subsided with time. A greater inflammatory reaction was observed at 7 days in the tubes filled with ZOEI paste. Tubes filled with MTA Fillapex presented some giant cells, macrophages and lymphocytes after 7 days. At 15 days, the presence of fibroblasts and collagen fibers was observed indicating normal tissue healing. The tubes filled with PCPG showed similar results to those observed in MTA Fillapex. At 15 days, the inflammatory reaction was almost absent at the tissue, with several collagen fibers indicating normal tissue healing. Data were analyzed by the nonparametric Kruskal-Wallis test (α=0.05). Statistically significant difference (p<0.05) was found only between PCPG at 15 days and ZOEI at 7 days groups. No significant differences were observed among the other groups/periods (p>0.05). MTA Fillapex and Portland cement added with propylene glycol had greater tissue compatibility than the PCPG paste.

O objetivo deste estudo foi avaliar a resposta do tecido subcutâneo de rato ao MTA Fillapex® (Angelus), a um cimento endodôntico experimental à base de cimento Portland e propilenoglicol, e à pasta de óxido de zinco e eugenol com iodofórmio. Estes materiais foram colocados em tubos de polietileno e implantados no tecido conjuntivo do dorso de ratos Wistar, por 7 e 15 dias. Os espécimes foram corados com hematoxilina e eosina e os parâmetros de reação inflamatória foram avaliados em microscópio óptico. A intensidade da resposta inflamatória provocada pelos cimentos foi analisada em todos os períodos por dois observadores previamente calibrados (kappa 0,96) e sem conhecimento dos grupos experimentais. O exame histológico mostrou que todos os materiais provocaram reação inflamatória moderada aos 7 dias que regrediu com o tempo. A maior resposta inflamatória do tecido foi observada aos 7 dias, nos tubos preenchidos com pasta de Óxido de Zinco e Eugenol com Iodofórmio. Os tubos com MTA Fillapex apresentaram algumas células gigantes, macrófagos e linfócitos após 7 dias. Aos 15 dias, a presença de fibroblastos e fibras de colágenas foi observada, indicando processo de cicatrização do tecido. Os tubos com o cimento Portland mostraram resultados semelhantes aos observados no grupo MTA Fillapex. Aos 15 dias, a reação inflamatória apresentada foi praticamente ausente, com muitas fibras colágenas, indicando cicatrização normal do tecido. A análise estatística mostrou diferença estatisticamente significante entre o grupo de cimento Portland (15 dias) e óxido de zinco eugenol com Iodofórmio (7 dias) (p<0,05). Nos outros grupos não houve diferença estatística significante. MTA Fillapex e cimento Portland são mais biocompatíveis do que os outros cimentos testados.

Expressão de transcritos de genes homeobox no carcinoma epidermóidede boca: análise por microarray, validação por qRT-PCR e relação com critériosclínicos de agressividade / Homeobox genes transcripts expression in oral squamous cell carcinoma: microarray analysis, qRT-PCR validation and association with clinical criteria of aggressiveness

A busca de marcadores moleculares para o refinamento diagnóstico, classificação eestabelecimento do prognóstico dos tumores, e individualização terapêutica tem sidofoco de várias pesquisas. O presente estudo teve como objetivo investigar, emcarcinoma epidermóide de língua e/ou assoalho bucal, a presença de transcritos dosgenes homeobox que pudessem se revelar marcadores moleculares de prognósticoe/ou agressividade tumoral. Após análise por microarray utilizando-se amostras detumores e margens classificados como mais e menos agressivos, os geneshomeobox HOXC13, HOXD10, HOXD11, IRX4, PROX1 e ZHX1 foram selecionadose sua hiper-expressão foi parcialmente validada por qRT-PCR. Observou-seaumento da expressão de HOXD10, HOXD11 e IRX4 em tumores com relação àsmargens correspondentes, bem como nos tumores menos agressivos em relação àssuas respectivas margens. Por outro lado, os genes PROX1 e ZHX1 estavam maisexpressos nas margens que nos tumores correspondentes. Esses resultadossugerem que a expressão alterada de HOXD10, HOXD11 e IRX4 pode participar nodesenvolvimento do carcinoma epidermóide de língua e/ou assoalho bucal,enquanto os genes PROX1 e ZHX1 provavelmente exibem perda de função ouestão silenciados na neoplasia. Houve uma tendência de associação entre aexpressão elevada de HOXD11 e presença de infiltrações linfática e perineural, egrau moderado de diferenciação da neoplasia, bem como entre a expressão elevadade HOXD10 e infiltração linfática. O gene IXR4 foi relacionado com um menor tempode sobrevida global. Não foi possível estabelecer, dentre os genes homeoboxvalidados por qRT-PCR, um gene ou uma combinação deles que pudesse(m) serutilizado(s) como marcador(es) de agressividade tumoral.

The search for molecular markers to diagnosis improvement, treatmentindividualization and establishment of oral squamous cell carcinoma prognosis hasbeen the focus of several studies. The present study investigated the presence ofspecific transcript of homeobox genes in squamous cell carcinoma of the tongueand/or floor of the mouth that might reflect relevant molecular markers of prognosisand/or tumor aggressiveness. After microarray analysis of tumor samples classifiedas more or less aggressive, and non tumoral margins, HOXC13, HOXD10, HOXD11,IRX4, PROX1 and ZHX1 selected and partially validated by qRT-PCR. Increasedexpression of HOXD10, HOXD11, IRX4 in tumors in comparison to margins as wellas in less aggressive tumors related to their margins was observed. On the otherhand, a decreased expression of PROX1 and ZHX1 was observed in marginscompared to their respective tumors. These results suggest that the alteredexpression of HOXD10, HOXD11 and IRX4 may participate in the development ofsquamous cell carcinoma of the tongue and/or floor of the mouth, while PROX1 andZHX1 probably present loss of function or are silenced in tumors. A tendency ofassociation between increased expression of HOXD11 and lymphatic and perineuralinfiltration, as well as moderately differentiated tumors, and increased expression ofHOXD10 and lymphatic infiltration was observed. Still, increased expression of IRX4may apparently influence global survival rate. However, the results of the presentstudy must be confirmed in a greater number of samples, and complemented with theevaluation of HOXD10, HOXD11, IRX4 protein levels. It was not possible toestablish, among homeobox genes validated through qRT-PCR, a gene or acombination of genes capable of predicting tumor aggressiveness.