The aim of this in vitro study was to investigate the effect of the cariostatic and preventive agent silver diamine fluoride (SDF) on the microtensile bond strength of resin composite to dentin. Forty-two caries-free, extracted molars were flattened occlusally and apically using a diamond saw, and the exposed occlusal dentin was polished with a series of silicon carbide papers, all under water irrigation. The teeth were then randomly divided into six groups of seven teeth each that were treated as follows: 1) Peak SE self-etch bonding agent; 2) 12% SDF + Peak SE; 3) 38% SDF + Peak SE; 4) Peak LC etch-and-rinse bonding agent; 5) 12% SDF + Peak LC; and 6) 38% SDF + Peak LC. Four-millimeter buildups of Amelogen Plus were incrementally placed on all teeth; after a 24-hour storage period in distilled water, the specimens were sectioned perpendicular to the adhesive interface to produce beams of cross-sectional surface area measuring approximately 1 mm(2). The beams were placed on a microtensile testing machine, which utilized a single-speed pump motor and force gauge at 20 kgf × 0.01 second to record maximum tensile force before failure occurred. Two-way analysis of variance and post hoc Tukey tests were performed to compare the effects of the SDF on microtensile bond strength, with statistical significance set at α = 0.05. None of the experimental groups treated with different concentrations of SDF showed a significant difference in bond strength compared to the control groups, and there was no significant difference in bond strength between self-etch and etch-and-rinse groups. However, the effect of SDF on self-etch bonded teeth compared to etch-and-rinse bonded teeth was statistically significant (p=0.0363), specifically at the 12% concentration. SDF does not adversely affect the bond strength of resin composite to noncarious dentin.

Pre-eruptive intracoronal resorption (PEIR) is a rare radiolucent lesion often located within the dentin and adjacent to the dentin-enamel junction, underneath the occlusal aspect of the crowns of unerupted teeth. The treatment approaches for these lesions involved with unerupted teeth have been known as to be relatively simple; depending on the extent of resorption, follow-up or restoration can be performed after surgical exposure. However, once the tooth is exposed to the oral cavity after eruption, it becomes highly vulnerable to the development of carious lesions. Thus, immediate intervention is required in such cases; failure to address it may result in the need for more complex treatments including endodontic therapy. The aim of this case report was to describe the characteristics of PEIR and the clinical management of the impacted immature permanent teeth diagnosed with PEIR.

In order to establish the bleaching process for cotton fabrics under the neutral condition, cotton fabrics were bleached by hydrogen peroxide with urea. It was revealed that hydrogen peroxide bleaching with urea showed the higher whiteness of bleached fabrics than that without urea at more than 70. Tensile strength did not decrease after bleaching. Some radicals were observed by ESR measurement when urea was added into hydrogen peroxide aqueous solution. The effects of urea on hydrogen peroxide bleaching seems to be caused by active oxygen ; hydroxyl radical (HO•), perhydroxyl radical (HOO•) and superoxide anion radical (O2• −) as well as perhydroxyl anion (HOO −). The residual hydrogen peroxide concentrations in bleaching baths were measured. When urea is added to the bleaching baths, the decomposition of hydrogen peroxide is accelerated even in the neutral bath.

In order to establish the bleaching method for cotton fabrics under the neutral or acid condition, the cotton fabrics were pretreated by iron(II) sulfate before subsequent hydrogen peroxide bleaching. The white index and tensile strength at break for yarns from bleached fabrics were measured and considered concerning the pretreated condition by iron(II) sulfate. It was revealed that the high white index attained, by contraries, tensile strength for yarns decreased ca. 20% by processing. However, an addition of a small amount of sodium hydroxide into bleaching bath enabled to depress a decrease of tensile strength for yarns. In addition, it was observed by ESR measurement that an amount of radicals increased when a small amount of NaOH was added into hydrogen peroxide solution in the presence of iron (II) sulfate.

This study aimed to evaluate the nasopharyngeal and oropharyngeal dimensions of the patients with skeletal class II division 1 or division 2 patterns during the pre-peak, peak, and post-peak growth periods for comparison with a skeletal class I control group (79 for pre-peak, 40 for peak, 40 for post-peak). Total 159 lateral cephalograms (70 for skeletal class I, 51 for skeletal class II, division 1, and 38 for skeletal class II, division 2) were selected.The growth of anteroposterior dimension of the pharyngeal airway were statistically significant among growth periods. The dimension for the nasopharyngeal and oropharyngeal airway space was the smallest in the division 1 skeletal class II group followed by class II division 2 and skeletal class I. Abstract98