Effect of airborne particle abrasion on microtensile bond strength of total-etch adhesives to human dentin

Aim of this study was to investigate a specific airborne particle abrasion pretreatment on dentin and its effects on microtensile bond strengths of four commercial total-etch adhesives. Midcoronal occlusal dentin of extracted human molars was used. Teeth were randomly assigned to 4 groups according to the adhesive system used: OptiBond FL (FL), OptiBond Solo Plus (SO), Prime & Bond (PB), and Riva Bond LC (RB). Specimens from each group were further divided into two subgroups: control specimens were treated with adhesive procedures; abraded specimens were pretreated with airborne particle abrasion using 50 mu m Al2O3 before adhesion. After bonding procedures, composite crowns were incrementally built up. Specimens were sectioned perpendicular to adhesive interface to producemultiple beams, which were tested under tension until failure. Data were statistically analysed. Failure mode analysis was performed. Overall comparison showed significant increase in bond strength (p < 0.001) between abraded and no-abraded specimens, independently of brand. Intrabrand comparison showed statistical increase when abraded specimens were tested compared to no-abraded ones, with the exception of PB that did not show such difference. Distribution of failure mode was relatively uniform among all subgroups. Surface treatment by airborne particle abrasion with Al2O3 particles can increase the bond strength of total-etch adhesive

Alcune riflessioni sui rapporti tra la memoria dei campi di concentramento fascisti e le nuove forme digitali di divulgazione storica

L’articolo propone alcune riflessioni sui rapporti tra la memoria dei campi di concentramento fascisti e le nuove forme digitali di divulgazione storica, analizzando e contestualizzando i contributi che appaiono nel presente forum.The article offers some reflections on the relationship between the memory of the fascist concentration camps and the new digital forms of historical popularization and outreaching, introducing and locating within current scholarship trends the contributions published in this forum

"Armato di carnagione": Chromatic Regimes of Racial Profiling in the Italian Press.

Marcello Messina, Stefania Capogreco. "Armato di carnagione": Chromatic Regimes of Racial Profiling in the Italian Press. Francielle Maria Modesto Mendes; Francisco Aquinei Timóteo Queirós; Wagner da Costa Silva. Pesquisa em comunicação: jornalismo, raça e gênero, Nepan Editora, 2021, 978-65-89135-20-3

Orthodontic brackets removal: morphological in vitro evaluation

Debonding procedure is a fundamental stage in the orthodontic treatment (1). Adhesive removal should lead to a complete polished enamel in order to prevent the plaque accumulation and enamel injures (2). Aim of this study is to evaluate in vitro by use of Scanning Electron Microscopy (SEM) the enamel surface after the bracket removal and the enamel polishing with four different techniques. Two groups of teeth, group A (n=12) and group B (n=12) were evaluated. The images were analyzed by the Image J software. After the debonding procedure the two groups were subcategorized in four groups (1A, 1B, 2A, 2B 3A, 3B and 4A, 4B, n.=3). The discriminant between the two main categories was the use of a magnification system (Group A) during the polishing stages. From the qualitative and quantitative images analysis the most conservative technique resulted to be the use of tungsten carbide bur, followed by the final polishing using the soft-polisher tip for composites. In group A, the percentage of the residual adhesive resulted 8% and the damages on the enamel surface showed to be 7%. In group B the percentage of the residual adhesive resulted 35% and the damages on the enamel surface showed to be 15%. This analysis showed how the use of a magnification system aids in significant way during the debonding procedures in the enamel surfaces’ preservation.The authors are grateful to Dr. M. Gianmatteo and to Dr. E. Nazaj, University of L’Aquila, for their help in the sampling and microscopy procedures

Immediate Occlusal Loading of One-Piece Zirconia Implants: Five-Year Radiographic and Clinical Evaluation

PURPOSE: To evaluate radiographic and clinical outcomes of immediate occlusally loaded one-piece zirconia implants after 5 years of follow-up. MATERIALS AND METHODS: This longitudinal clinical investigation included patients older than 18 years, in need of implant-supported single-unit dental rehabilitations. One-piece zirconia in healed and postextraction sites and immediately restored with provisional crowns in light occlusal contact. Definitive zirconia-ceramic restorations were delivered 3 to 4 months after surgery. Primary estimated outcomes were implant survival and success. Periapical radiographs were taken at implant insertion (T0), after 1 year (T1), and after 5 years (T2) to assess marginal bone loss (MBL). Probing depth (PD), modified Bleeding Index (mBI), modified Plaque Index (mPI), and gingival recession (REC) were also measured repeatedly for implants and reference teeth. Changes in parameters over time were assessed using the Wilcoxon signed rank test. In addition, multilevel mixed effects linear and logistic regression models were fitted to take into account within-subject correlations and baseline values. RESULTS: Thirty-two implants were inserted in postextraction and healed sites (n = 16 of each) in 17 patients. One immediate implant was lost after 3 months, and one patient with one implant dropped out after T1. Therefore, the cumulative survival rates were 96.9% at T1 and 96.8% at T2 (4.3 to 6 years). No significant differences were observed in mean MBL between immediate and delayed implants at either T1 or T2. Moreover, different baseline parameters (sex, arch, implant location, smoking habits, grafting) did not show any influence on MBL at either time. In general, for all clinical parameters (PD, mBI, mPI, REC), implants seemed to perform similar to if not better than natural teeth. CONCLUSION: Radiographic and clinical evaluations after 5 years showed satisfactory amounts of MBL and acceptable soft tissue health

Analisi delle proprietà meccaniche di laminati in CFRP soggetti a invecchiamento igroscopico

La seguente tesi illustra lo svolgimento di un'analisi sperimentale eseguita in due fasi principali. La prima fase è stata svolta presso i laboratori dell’Hangar di Forli, in cui i provini sono stati realizzati, danneggiati con impatti BVID ed invecchiati igroscopicamente. La seconda fase è stata svolta nei laboratori ENEA di Faenza-Unità Tecnica Tecnologie dei Materiali, in cui sono stati effettuati i test a compressione