Micro-shear bond strength and surface micromorphology of a feldspathic ceramic treated with different cleaning methods after hydrofluoric acid etching

Objective

The aim of this study was to evaluate the effect of feldspathic ceramic surface cleaning on micro-shear bond strength and ceramic surface morphology.

Material and Methods

Forty discs of feldspathic ceramic were prepared and etched with 10% hydrofluoric acid for 2 minutes. The discs were randomly distributed into five groups (n=8): C: no treatment, S: water spray + air drying for 1 minute, US: immersion in ultrasonic bath for 5 minutes, F: etching with 37% phosphoric acid for 1 minute, followed by 1-minute rinse, F+US: etching with 37% phosphoric acid for 1 minute, 1-minute rinse and ultrasonic bath for 5 minutes. Composite cylinders were bonded to the discs following application of silane and hydrophobic adhesive for micro-shear bond strength testing in a universal testing machine at 0.5 mm/min crosshead speed until failure. Stereomicroscopy was used to classify failure type. Surface micromorphology of each treatment type was evaluated by scanning electron microscopy at 500 and 2,500 times magnification.

Results

One-way ANOVA test showed no significant difference between treatments (p=0.3197) and the most common failure types were cohesive resin cohesion followed by adhesive failure. Micro-shear bond strength of the feldspathic ceramic substrate to the adhesive system was not influenced by the different surface cleaning techniques. Absence of or less residue was observed after etching with hydrofluoric acid for the groups US and F+US.

Conclusions

Combining ceramic cleaning techniques with hydrofluoric acid etching did not affect ceramic bond strength, whereas, when cleaning was associated with ultrasound, less residue was observed.     

Multi‐tissue cytogenetic analysis for the diagnosis of mosaic Down syndrome: A case report

Less than one percent of individuals with Down syndrome exhibit mosaicism, a biological phenomenon that describes an individual who has two or more genetically distinct cell lines. The percentage of mosaicism in different tissues can impact the presence of clinical findings and hinder cytogenetic diagnosis. We report a case of mosaicism for trisomy 21 diagnosed after multi‐tissue cytogenetic analysis of peripheral blood and buccal mucosa, associated with significant intellectual disability, dysmorphic facial features, congenital heart defects, macropenis, and imperforate anus.     

Bladder amyloidosis: report of 2 cases

Two cases of amyloidosis of the bladder are reported: 1) a 45 year old man with haematuria. Cystoscopic examination reveals several tumours in the wall of the bladder. Transuretral resection was performed and histopathological examination revealed primary amyloidosis. Systemic amyloidosis was excluded. He was treated with oral colchicine with success. 2) a 71 year old male with diagnosis of rheumatoid arthritis and systemic amyloidosis visited our hospital with massive haematuria. Transuretral resection was unsuccessful and was necessary surgical ligation of hypogastric arteries.     

Congenital Degos Disease: Case Report and Dermoscopic Findings

Pediatric Degos disease is rare, with only 36 cases reported in the medical literature. Classically the diagnosis has been established according to pathognomonic histopathologic findings, but when these features are not present, there may be a delay in diagnosis. We report the second congenital case of Degos disease, highlighting the clinical and dermoscopic findings.     

Asociación entre el hydrops endolinfático y vértigo posicional paroxístico benigno: ¿casualidad o causalidad?

IntroductionThe aim of this study was to determine the prevalence of benign paroxysmal positional vertigo (BPPV) in patients diagnosed with endolymphatic hydrops (EH) and to analyze whether this association is a factor for poor prognosis in these patients.Material and methodsA retrospective study was carried out in our department among the patients definitively diagnosed as having Ménière's disease according to the criteria of the American Academy of Otolaryngology and BPPV by the usual triggering manoeuvres.ResultsThe prevalence of BPPV in our patients with EH was 5.1%. The rate of cure with the repositioning manoeuvres is 90.9%, however success with the first manoeuvre was only 63.36%. Recurrences occurred in up to 22.22%. We found a lower success rate with the first manoeuvre in relation to the rest of the patients with BPPV without EH. This difference is statistically significant (P=0.042).DiscussionWe did not find that these patients to have a lower rate of cure with the repositioning manoeuvres or a higher rate of recurrence. But in our protocol the first manoeuvre had a lower success rate than in the rest of the patients.