abstract rice can be cultivated in various soils but soil with heavy texture and low permeability is more appropriate for its growth than other types of soil texture. it’s assumed that existence of zeolite in soil can be effective for moisture retention and avoiding of occurrence of crack in soil. in order to investigation of the effect of zeolite on moisture status and hydraulic properties of ...

Enamel formation requires consecutive stages of development to achieve its characteristic extreme mineral hardness. Mineralization depends on the initial presence then removal of degraded enamel proteins from the matrix via endocytosis. The ameloblast membrane resides at the interface between matrix and cell. Enamel formation is controlled by ameloblasts that produce enamel in stages to build t...

OBJECTIVE Ethanol wet-bonding (EWB) technique has been stated to decrease degradation of resin-dentin bond. This study evaluated the effect of two EWB techniques on composite resin-to-enamel bond strength. MATERIALS AND METHODS Silicon carbide papers were used to produce flat enamel surfaces on the buccal faces of forty-five molars. OptiBond FL (OFL) adhesive was applied on enamel surfaces in...

OBJECTIVE Interproximal enamel reduction is a part of orthodontic treatment for gaining a modest amount of space in the treatment of crowding. Today interproximal enamel reduction has become a viable alternative to the extraction of permanent teeth, and helps to adjust the Bolton Index discrepancy. The aim of the study is to evaluate various interproximal enamel reduction techniques, its indica...

OBJECTIVES To determine if Sa roughness data from measuring one central location of unpolished and polished enamel were representative of the overall surfaces before and after erosion. METHODS Twenty human enamel sections (4x4 mm) were embedded in bis-acryl composite and randomised to either a native or polishing enamel preparation protocol. Enamel samples were subjected to an acid challenge ...

Recaldent is a product of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). The remineralizing potential of CPP-ACP per se, or when combined with 0.22% Fl gel on artificially demineralized enamel using laser florescence, is investigated. Mesial surfaces of 15 sound human molars are tested using a He-Cd laser beam at 441.5 nm with 18-mW power as an excitation source on a suitable setu...

Rhythmic incremental growth lines and the presence of melatonin receptors were discovered in tooth enamel, suggesting possible role of circadian rhythm. We therefore hypothesized that circadian rhythm may regulate enamel formation through melatonin receptors. To test this hypothesis, we examined expression of melatonin receptors (MTs) and amelogenin (AMELX), a maker of enamel formation, during ...

Pre-softened, gauze-covered bovine enamel blocks were worn in the buccal sulcus of five subjects for seven days. Artificial plaque enmeshed in the gauze was treated four times per day for four days with an enzyme-dependent mineralizing solution, resulting in 20-, 10-, and 200-fold increases in Ca, P, and F, respectively. Enamel beneath this mineral-enriched plaque recovered 37% of the hardness ...

Enamel formation depends on a triad of tissue-specific matrix proteins (amelogenin, ameloblastin, and enamelin) to help initiate and stabilize progressively elongating, thin mineral ribbons of hydroxyapatite formed during an appositional growth phase. Subsequently, these proteins are eradicated to facilitate lateral expansion of the hydroxyapatite crystallites. The purpose of this study was to ...

As fretting fatigue cracks are initiated at an early stage of life, the fretting fracture process is dominated by the stable growth of cracks. Hence the measurement of crack length is very important. This paper demonstrates the suitability of the DC potential drop technique for the measurement of fretting cracks. A calibration has been established for monitoring crack growth in BS L65 copper al...