Cross Talk between Apical Periodontitis and Metabolic Disorders: Experimental Evidence on the Role of Intestinal Adipokines and Akkermansia muciniphila.

INTRODUCTION: Infection and dysbiosis present a close relationship with metabolic diseases although the influence of apical periodontitis (AP) in this context needs further investigation. This study evaluated the influence of AP in a rat model of metabolic syndrome induced by 10% fructose supplementation. METHODS: Male Wistar rats were used. Animals that received a high-fructose diet (HFD, n = 30) or filtered water (control, n = 30) were subdivided into the following groups: (1) without induction of AP (no AP, n = 10 each), (2) with AP induction 2 weeks before euthanasia (AP 14 days, n = 10 each), and (3) with AP induction 4 weeks before euthanasia (AP 28 days, n = 10 each). RESULTS: HFD triggered metabolic syndrome, as indicated by the induction of overweight and hyperglycemia, besides polydipsia, regardless of the AP induction. Serum or intestinal tumor necrosis factor, interleukin 1 beta, and interleukin 6 levels were undetectable, regardless of the experimental group. Serum leptin and adiponectin levels were significantly elevated in the HFD group without AP induction. The intestinal levels of leptin were significantly increased in the groups with 28 days of AP induction despite HFD. A significant elevation of liver glutathione levels was observed in animals submitted to HFD and AP for 14 days. AP induction (14 or 28 days) led to pulp and periapical tissue inflammation without any influence of HFD. Either HFD or AP induction led to dysbiosis, as indicated by a significant reduction of fecal A. muciniphila expression. CONCLUSIONS: We provide novel evidence that AP can have systemic impacts on metabolic disorders, likely by modulating intestinal metabolism and microbiota.

Intracanal delivery of Resolvin E1 controls inflammation in necrotic immature rat teeth.

INTRODUCTION: Pulp necrosis in immature teeth and the resulting periodontal apical inflammation negatively affect root formation. Resolvin E1 (RvE1) is a lipid-derived endogenous pro-resolution molecule that controls inflammation. The aim of this investigation was to evaluate the impact of RvE1 applied as an intracanal medication on root formation in nonvital immature teeth. METHODS: To arrest root development, pulpectomy was performed in the lower first molars of 4-week-old Wistar rats. After 3 weeks, irrigation with 2.5% sodium hypochlorite and 0.9% sterile saline was performed, and either a triple antibiotic paste (TAP) or RvE1 in saline was applied into the root canals. In the control group, access openings drilled into molars were left exposed to the oral environment. Root development and periapical repair were evaluated radiographically and histologically at 3 and 6 weeks after treatment. RESULTS: RvE1 reduced periapical lesion size compared with the control at 3 weeks, which was similar to TAP. Inflammatory response in the RvE1-treated group was markedly reduced compared with both TAP and control specimens. At 6 weeks, root development was observed in both groups, but RvE1 treatment produced less cellularity with more regular calcified tissue deposition. CONCLUSIONS: RvE1 and TAP had a positive impact on reducing inflammation and promoting root formation. RvE1 was more effective in reducing inflammation at earlier stages. RvE1 has potential to be used as root canal dressing to control inflammation in endodontically compromised teeth before complete root formation. Stability of RvE1 within the root canal and its delivery are issues to be addressed before its clinical use.

Técnica híbrida para preparo de canais radiculares curvos / Hibrid technique for curve root canal preparation

O momento atual da endodontia compartilha com expressivas mudanças, requintados recursos tecnológicos, materiais com excelentes qualidades biológicas, físico-químicas e mecânicas. Presenciam a necessidade de instrumentos inteligentes, técnicas eficazes que demandam pouco tempo de trabalho, simplificação nos passos operatórios e, em contrapartida, requer cada vez mais conhecimento básico, pois os procedimentos técnicos atuam sobre estruturas biológicas. A cada dia surgem novos instrumentos e novas técnicas representando novos e requintados sistemas. O interessante é que os principios essenciais e os elementos fundamentais no preparo do canal se mantêm (como esvaziar, ampliar, sanificar e preencher). O paradigma permanece em busca da vitória frente à complexa anatomia interna, aos microrganismos e a resposta do hospedeiro. O raciocínio atual direciona ao emprego de uma técnica de preparo com avanço progressivo em sentido apical, a partir do preparo cervical. Com advento dos instrumentos de níquel-titânio, de recohecida flexibilidade, acionados manualmente e a motor, têm-se observado melhora na qualidade da forma do preparo, pequeno tempo de trabalho, redução de stress do profissional, o que torna oportuno agregá-los a uma técnica de instrumentação. O objetivo deste estudo é apresentar e discutir a proposição de uma técnica híbrida, em que se associa à técnica de preparo cervical a utilização de limas de níquel-titânio movida a motor. A sequência dos passos operatórios envolve: 1. Exploração do canal radicular. 2. Preparo do orifício de entrada e terço cervical do canal. 3. Odontometria. 4. Preparo do terço aplical (utilização de limas de níquel titânio acionadas a motor e limas de aço inoxidável)

Aspectos preventivos e terapêuticos das perfurações iatrogênicas em endodontia / Preventive and therapeutic aspects of iatrogenic perforations in endodintics

Os autores objetivam, através da revisão da literatura odontológica, atualizar os conhecimentos para os que praticam a endodontia, acerca da prevenção e terapêutica das perfurações iatrogênicas