Influence of Abutment Design on Biomechanical Behavior to Support a Screw-Retained 3-Unit Fixed Partial Denture

This study aimed to evaluate the biomechanical behavior of Morse taper implants using different abutments (CMN abutment [(CMN Group] and miniconical abutments [MC Group]), indicated to support a screw-retained 3-unit fixed partial denture. For the in vitro test, polyurethane blocks were fabricated for both groups (n = 10) and received three implants in the “offset” configuration and their respective abutments (CMN or MC) with a 3-unit fixed partial denture. Four strain gauges were bonded to the surface of each block. For the finite element analysis, 3D models of both groups were created and exported to the analysis software to perform static structural analysis. All structures were considered homogeneous, isotropic, and elastic. The contacts were considered non-linear with a friction coefficient of 0.3 between metallic structures and considered bonded between the implant and substrate. An axial load of 300 N was applied in three points (A, B, and C) for both methods. The microstrain and the maximum principal stress were considered as analysis criteria. The obtained data were submitted to the Mann–Whitney, Kruskal–Wallis, and Dunn’s multiple comparison test (α = 5%). The results obtained by strain gauge showed no statistical difference (p = 0.879) between the CMN (645.3 ± 309.2 με) and MC (639.3 ± 278.8 με) and allowed the validation of computational models with a difference of 6.3% and 6.4% for the microstrains in the CMN and MC groups, respectively. Similarly, the results presented by the computational models showed no statistical difference (p = 0.932) for the CMN (605.1 ± 358.6 με) and MC (598.7 ± 357.9 με) groups. The study concluded that under favorable conditions the use of CMN or MP abutments to support a fixed partial denture can be indicated.     

Autoimmune hepatitis in 828 Brazilian children and adolescents: clinical and laboratory findings,histological profile,treatments, and outcomes

ObjectiveThis large study with a long-term follow-up aimed to evaluate the clinical presentation, laboratory findings, histological profile, treatments, and outcomes of children and adolescents with autoimmune hepatitis.MethodsThe medical records of 828 children and adolescents with autoimmune hepatitis were reviewed. A questionnaire was used to collect anonymous data on clinical presentation, biochemical and histological findings, and treatments.ResultsOf all patients, 89.6% had autoimmune hepatitis-1 and 10.4% had autoimmune hepatitis-2. The female sex was predominant in both groups. The median age at symptom onset was 111.5 (6; 210) and 53.5 (8; 165) months in the patients with autoimmune hepatitis 1 and autoimmune hepatitis-2, respectively. Acute clinical onset was observed in 56.1% and 58.8% and insidious symptoms in 43.9% and 41.2% of the patients with autoimmune hepatitis-1 and autoimmune hepatitis-2, respectively. The risk of hepatic failure was 1.6-fold higher for autoimmune hepatitis-2. Fulminant hepatic failure occurred in 3.6% and 10.6% of the patients with autoimmune hepatitis-1 and autoimmune hepatitis-2, respectively; the risk was 3.1-fold higher for autoimmune hepatitis-2. The gamma globulin and immunoglobulin G levels were significantly higher in autoimmune hepatitis-1, while the immunoglobulin A and C3 levels were lower in autoimmune hepatitis-2. Cirrhosis was observed in 22.4% of the patients; biochemical remission was achieved in 76.2%. The actuarial survival rate was 93.0%. A total of 4.6% underwent liver transplantation, and 6.9% died (autoimmune hepatitis-1: 7.5%; autoimmune hepatitis-2: 2.4%).ConclusionsIn this large clinical series of Brazilian children and adolescents, autoimmune hepatitis-1 was more frequent, and patients with autoimmune hepatitis-2 exhibited higher disease remission rates with earlier response to treatment. Patients with autoimmune hepatitis-1 had a higher risk of death.