Wear behavior of monolithic zirconia against natural teeth in comparison to two glass ceramics with two surface finishing protocols: an in-vitro study / Comportamento do desgaste da zircônia monolítica frente a dentes naturais em comparação com duas cerâmicas de vidro com diferentes protocolos de acabamento superficial: um estudo in vitro

Objective: To evaluate and compare the wear behavior of three different ceramic systems; monolithic zirconia, lithium di-silicate and nano-fluorapatite glass ceramic with two finishing procedures polishing and glazing, and their effect on the wear of natural tooth antagonists. Material and Methods: Forty two ceramic disc specimens (10mm x3mm) and forty two natural tooth antagonists were used. Samples were divided according to ceramic materials into 3 groups (n = 14). Group I: nano-fluorapatite glass ceramic (FLU) (IPS e.max Ceram), Group II: lithium disilicate (LD) (IPS e.max CAD) and group III: monolithic zirconia (ZIR) (ZirkoZahn Prettau). Each group was further subdivided into two subgroups (n = 7), according to the surface finish: Polishing (P) and glazing (G). Specimens were subjected to a custom designed two-body wear simulator. Quantitative wear assessment was carried out using weight loss measurements. Scanning electron microscope was used for characterization of wear patterns. Kruscal Wallis and Dunn's tests were used to compare between weight loss of the three ceramic materials. Whitney U test was used to compare the weight loss between the two surface finish protocols. Wilcoxon Signed rank test was used to compare the weight loss between ceramic specimens and antagonist teeth (p ≤ 0.05). Paired t-test was used to compare weight loss before and after wear test. Results: After wear, LD and FLU had the highest weight loss values compared to ZIR (p < 0.05). For teeth, there was no significant difference between the weight loss values with the three materials (p > 0.05). P and G specimens showed no significant difference in weight loss values. SEM images of the wear patterns verified the previous analysis. Conclusion: ZIR is more wear resistant than LD and FLU. However, the surface treatment had no impact on the wear behavior. (AU)

Objetivo: Avaliar e comparar o comportamento ao desgaste de três diferentes sistemas cerâmicos; zircônia monolítica, di-silicato de lítio e vitrocerâmica de nano-fluorapatita com dois procedimentos de polimento e glaze, e seu efeito no desgaste de dentes naturais antagonistas. Material e Métodos: Foram utilizadas quarenta e duas amostras de discos cerâmicos (10 mm x 3 mm) e quarenta e dois dentes naturais como antagonistas. As amostras foram divididas de acordo com o material cerâmico em 3 grupos (n = 14). Grupo I: vitrocerâmica nano-fluorapatita (FLU) (IPS e.max Ceram), Grupo II: dissilicato de lítio (LD) (IPS e.max CAD) e grupo III: zircônia monolítica (ZIR) (ZirkoZahn Prettau). Cada grupo foi subdividido em dois subgrupos (n = 7), de acordo com o acabamento da superfície: Polimento (P) e Glaze (G). As amostras foram submetidas a um simulador de desgaste de dois corpos projetado. A avaliação quantitativa do desgaste foi realizada usando medidas de perda de massa. Microscópio eletrônico de varredura foi utilizado para caracterização de padrões de desgaste. Os testes de Kruscal Wallis e Dunn foram usados para comparar a perda de massa dos três materiais cerâmicos. O teste U de Whitney foi utilizado para comparar a perda de massa entre os dois protocolos de acabamento superficial. O teste de Wilcoxon Signed Rank foi utilizado para comparar a perda de massa entre amostras de cerâmica e os dentes antagonistas (p ≤ 0,05). O teste t pareado foi utilizado para comparar a perda de massa antes e depois do teste de desgaste. Resultados: Após o desgaste, LD e FLU apresentaram os maiores valores de perda de massa em comparação ao ZIR (p < 0,05). Para os dentes, não houve diferença significativa entre os valores de perda de massa com os três materiais (p > 0,05). As amostras de P e G não mostraram diferença significativa nos valores de perda de massa. Imagens SEM dos padrões de desgaste confirmaram a análise anterior. Conclusão: O ZIR é mais resistente ao desgaste do que LD e FLU. No entanto, o tratamento de superfície não teve impacto no comportamento do desgaste. (AU)

Predictors of outcome following hip fracture rehabilitation.

OBJECTIVE: To determine the potential predictors of functional outcome after hip fracture rehabilitation in a large acute inpatient rehabilitation facility. DESIGN: Retrospective chart review study. SETTING: Large acute inpatient rehabilitation hospital. PARTICIPANTS: Patients admitted with a primary admitting diagnosis of hip fracture (n = 753). Patients were excluded if their hip fracture was the result of high-velocity trauma and if their stay was shorter than 48 hours (196 patients). METHODS: Independent variables included body mass index, gender, ethnicity, smoking history, alcohol consumption, past living situation, past ambulatory status, medical history, prealbumin level, medications that increase the risk of falling, and evidence of prior osteoporosis workup and treatment. These data were entered into a password-encrypted database. Univariate analyses were carried out to evaluate the relationship between independent variables and main outcomes, and multivariate analyses were performed to assess the impact of medical history of diabetes adjusting for other covariates. MAIN OUTCOME MEASUREMENTS: Discharge location; length of rehabilitation hospital stay (LOS); Functional Independence Measure (FIM) gain, which is calculated as the FIM(discharge) - FIM(admission); and length of stay efficiency (LOSE), which is calculated as the FIM gain divided by the LOS, and measures the rate of FIM change. RESULTS: Patients with diabetes had a worse LOSE (P = .0008). Multiple linear regression analysis revealed that patients who have a medical history of diabetes have a 0.33 reduction of LOSE compared with other patients. Predictors of better LOSE included younger age (P < .001), fewer medications that predispose to falls (P < .0001), and independent ambulation before fracture (P = .0003). CONCLUSION: We have found several significant patient characteristics that portend a better functional outcome after hip fracture. These include younger age, female gender, absence of diabetes mellitus, independent prefracture ambulation, not living alone before fracture, and being prescribed fewer medications that predispose to falling during rehabilitation. On the contrary, one of our most interesting findings is that patients with diabetes made slower gains, had a longer LOS and were less likely to be discharged directly home from the acute rehabilitation facility. There are numerous factors that may contribute to this, and suggestions are made for future research.