Periapical bone response to bacterial lipopolysaccharide is shifted upon cyclooxygenase blockage.

OBJECTIVES: Infection, inflammation and bone resorption are closely related events in apical periodontitis development. Therefore, we sought to investigate the role of cyclooxygenase (COX) in osteoclastogenesis and bone metabolism signaling in periapical bone tissue after bacterial lipopolysaccharide (LPS) inoculation into root canals. METHODOLOGY: Seventy two C57BL/6 mice had the root canals of the first molars inoculated with a solution containing LPS from E. coli (1.0 mg/mL) and received selective (celecoxib) or non-selective (indomethacin) COX-2 inhibitor. After 7, 14, 21 and 28 days the animals were euthanized and the tissues removed for total RNA extraction. Evaluation of gene expression was performed by qRT-PCR. Statistical analysis was performed using analysis of variance (ANOVA) followed by post-tests (α=0.05). RESULTS: LPS induced expression of mRNA for COX-2 (Ptgs2) and PGE2 receptors (Ptger1, Ptger3 and Ptger4), indicating that cyclooxygenase is involved in periapical response to LPS. A signaling that favours bone resorption was observed because Tnfsf11 (RANKL), Vegfa, Ctsk, Mmp9, Cd36, Icam, Vcam1, Nfkb1 and Sox9 were upregulated in response to LPS. Indomethacin and celecoxib differentially modulated expression of osteoclastogenic and other bone metabolism genes: celecoxib downregulated Igf1r, Ctsk, Mmp9, Cd36, Icam1, Nfkb1, Smad3, Sox9, Csf3, Vcam1 and Itga3 whereas indomethacin inhibited Tgfbr1, Igf1r, Ctsk, Mmp9, Sox9, Cd36 and Icam1. CONCLUSIONS: We demonstrated that gene expression for COX-2 and PGE2 receptors was upregulated after LPS inoculation into the root canals. Additionally, early administration of indomethacin and celecoxib (NSAIDs) inhibited osteoclastogenic signaling. The relevance of the cyclooxygenase pathway in apical periodontitis was shown by a wide modulation in the expression of genes involved in both bone catabolism and anabolism.

Alternative fixation system for implant-retained overdenture: case report / Sistema alternativo de fixação para overdenture implanto-retida: relato de caso

ABSTRACT The aim of this case report was to describe a prosthetic rehabilitation associated with an alternative model of polymer capsule for fixation system of implant-retained overdentures. Patient sought treatment at the clinic of School of Dentistry of Ribeirão Preto, due to lack of retention of their conventional total superior prostheses and inferior overdenture. The initial complaint was clinicallyconfirmed by altered intermaxillary relationships and severe reabsorption of the maxillary crest. In order to restore the function and improve its quality of life, it was proposed a prosthetic solution including implant fixed prosthesis to maxilla and a mandibular overdenture, with ball-type attachments associated with an alternative model of polymer capsule. This treatment was proposed inorder to reestablish the intermaxillary relationships and adequate occlusion, maintain retention and stability of the prosthesis. At the end of treatment and during a one-year follow-up of the case, the patient reported satisfaction and significant improvement in quality of life.

RESUMO O objetivo deste relato de caso foi descrever uma reabilitação protética associada a um modelo alternativo de cápsula polimérica para sistema de fixação de overdentures implantado-retidas. Paciente procurou tratamento na clínica da Faculdade de Odontologia de Ribeirão Preto, devido falta de retenção de suas próteses totais superiores convencionais e overdenture inferior. A queixa inicialfoi clinicamente confirmada por relações intermaxilares alteradas e reabsorção severa da crista maxilar. Para restaurar a função e melhorar sua qualidade de vida, propôs-se como solução protética, a confecção de prótese fixa sobre implantes para a maxila e overdenture mandibular, com acessórios tipo bola associados a um modelo alternativo de cápsula polimérica. Esse tratamento foiproposto a fim de restabelecer as relações intermaxilares e a oclusão adequada, manter a retenção e a estabilidade da prótese. Ao final do tratamento e durante o acompanhamento de um ano do caso, o paciente relatou satisfação e melhora significativa na qualidade de vida.