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.

Efeito na reparação óssea periapical da ozonioterapia como coadjuvante ao tratamento endodôntico: estudo clínico-radiográfico / Effect in periapical bone healing of Ozone therapy as adjuvant to endodontic treatment clinical-radiographic essay

A reparação dos tecidos periapicais testemunha o êxito da terapia endodôntica. Por intervir de forma favorável na reparação tecidual, a ozonioterapia é reconhecida como um importante coadjuvante ao protocolo terapêutico, sendo oportuno verificar sua eficácia no caso da terapia endodôntica. Para isso, foi avaliada, in vivo a influência do gás ozônio, da água ozonizada e óleo ozonizado na reparação tecidual em situações de necrose pulpar com alterações ósseas periapicais, diagnosticado e caracterizado como quadros de infecção primária. Foram feitas radiografias previamente e ao final do tratamento e novamente no terceiro e no sexto mês após a conclusão da terapia endodôntica. Respeitando-se os critérios de inclusão, 36 pacientes da Clínica Odontológica da Faculdade de Odontologia da Universidade de São Paulo foram divididos aleatoriamente em 3 grupos: Grupo I (12 dentes) Controle: tratamento endodôntico segundo protocolo da Disciplina de Endodontia da FOUSP; Grupo II (12 dentes) protocolo terapêutico empregado pelo Grupo I e associado ao final com irrigação de 10 mL de água bidestilada ozonizada na concentração de 8 g/mL; e, Grupo III (12 dentes) protocolo terapêutico empregado pelo Grupo I e associado ao final do preparo do canal da aplicação de 10 mL do gás ozônio na concentração de 40 g/mL. Foi utilizado como medicação intracanal o hidróxido de cálcio veiculado em PRP no Grupo I e o óleo de girassol ozonizado (Philozon, Santa Catarina, SC, Brasil) nos Grupos II e III. As medicações permaneceram por um período de 15 dias e em seguida foi feita obturação com cimento AH-Plus. A avaliação da reparação óssea periapical foi realizada analisando as radiografias digitalizadas no programa ImageLab.

Após a delimitação e quantificação de pixels das lesões periapicais, as radiografias finais e controles de 3 e 6 meses foram comparadas, indicando o quanto de redução da radiolucência periapical. Paralelamente, foi feita a análise de sensibilidade pós-operatória utilizando uma Escala Visual Analógica. Os pacientes foram questionados com relação à sensibilidade previamente ao início do tratamento, 72 horas após consulta inicial e nos controles de 3 e 6 meses, devendo associá-la com uma nota de 0 a 10 de acordo com a intensidade. Os dados foram submetidos à análise de variância, complementado pelo teste de Tukey, com significância de 5%. Os três protocolos terapêuticos instituídos promoveram redução da imagem radiolúcida periapical sem diferença estatística significante. Na análise da sensibilidade, o Grupo III apresentou os melhores resultados, com diferença estatística significante em relação aos demais grupos. Com base nos dados obtidos e na análise estatística executada, foi possível concluir que a ozonioterapia, por meio do emprego do gás ozônio e água ozonizada na fase do preparo químico cirúrgico e do óleo ozonizado como medicação intracanal, interviu de maneira favorável na reparação, em situações de necrose pulpar com alterações ósseas periapicais, sendo o gás mais efetivo que a água ozonizada, com diferenças estatísticas significantes. Os 2 grupos experimentais de ozonioterapia comparado ao grupo controle (protocolo FOUSP) apresentaram padrão de reparação óssea semelhante. A utilização da água ozonizada como irrigante e do óleo ozonizado como medicação intracanal mostrou a melhor eficácia do ponto de vista sintomatológico.

The success of the endodontic treatment is related to the repair of the periapical tissues. The ozone therapy is known for its therapeutic usefulness, favorable tissue healing, thus it seems suitable for evaluating its efficiency in the endodontic therapy. The aim of this study was to evaluate in vivo the influence of ozone gas, ozonated water and oil in bone repair in cases of pulpar necrosis with radiographic evidence of periapical bone loss associated with primary endodontic infection. Radiographs (Xrays) were taken prior and after the completion of the endodontic treatment, three and six months later. According to the enclosure criteria, 36 patients of the Dental Clinic of the School of Dentistry, University of Sao Paulo, were selected and randomly divided in three groups: Group I (12 teeth) Control: endodontic treatment protocol according to the discipline of Endodontics FOUSP, Group II (12 teeth): endodontic protocol associated with final irrigation with 10 mL of bidestilated ozonated water at concentration of 8 g/mL and Group III (12 teeth): endodontic protocol associated with application of 10 mL of ozone gas at concentration of 40 g/mL. Calcium Hydroxide was used as intracanal medication for 15 days. In Group I it was associated with anesthetic solution and in the Groups II and III associated with ozonated oil (Philozon, Santa Catarina, SC, Brazil). After this period, all teeth were obturated with AH-Plus root canal sealer. Evaluation of periapical bone repair was performed with Image Lab software after image digitalization.

After delimitation and pixel quantification of the periapical lesion area of the images immediately after the endodontic treatment, 3 and 6-months follow up, the obtained data were compared indicating the quantum reduction of the periapical radiolucency. In parallel, a postoperative sensitivity analysis was performed using a Visual Analog Scale. Patients were asked to score the sensitivity from 0 to 10 according to its intensity prior to first appointment, 72 hours later the first visit, 3 and 6 months later. Data were submitted to analysis of variance (ANOVA), complemented by the Tukey test at 5% of significance. All the three groups promoted a reduction of the apical radiolucent image without statistical difference. In the sensitivity analysis, Group III showed the best results with statistically significant...

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.