Backscattered Scanning Electron Microscopy Images Research Articles

Maxillary sinus augmentation: Histomorphometric analysis of graft materials for maxillary sinus floor augmentation

This study used histomorphometric analysis to quantitate the bone composition of four different sinus grafting materials biopsied at the time of implant installation. The study consisted of five patients in whom eight bone biopsies were obtained from seven grafted sites. The grafting materials consisted of hydroxylapatite (HA) granules mixed with cortical chin bone, HA mixed with demineralized bone powder, HA alone, and cortical chin bone alone. Histomorphometry was performed using backscattered scanning electron microscopy images and a computerized image analysis system. The biopsy cores yielded 46 sections from which a total of 255 fields, measuring 2.0 mm x 2.0 mm each, were imaged and analyzed. The biopsy cores contained 44.4% bone after grafting with HA granules and chin bone, 59.4% bone after grafting with chin bone alone, 20.3% bone after grafting with HA granules alone, and 4.6% bone after grafting with HA granules and demineralized bone powder. The small number of biopsies did not permit analysis of statistical significance. However, this study demonstrated the feasibility of correlating mineralized tissue composition of different sinus grafting materials with clinical outcome after dental implant installation.

Insoluble phase in Al–1·52Cu–0·75Mg alloys containing silicon

Insoluble particles present in solution treated, quenched and aged Al–1·52Cu–0·75Mg alloys containing 0·23, 0·49, 0·76, and 1·03 wt-% Si have been investigated. Back-scattered scanning electron microscope images of polished sections of the alloys showed the presence of very small, nearly spherical particles at the grain boundaries of all alloys except that containing 0·23 wt-% Si. Alloys with 0·76 and 1·03 wt-% Si also contained large particles of well defined geometrical shapes. An electrolytic technique was used to extract the insoluble particles from the matrix. The extracted particles were analysed by energy dispersive X-ray analysis in a scanning electron microscope. They contained 20·6±0·4%Cu, 32·6±0·4%Mg, 30·2±0·4%Si, and 16·6±0·1%Al (all wt-%). X-ray diffraction analysis of these particles showed that they have a hexagonal structure with lattice parameters a=1·036±0·004 nm and c=0·404±0·004 nm. The insoluble particles were identified as quarternary phase Q. Aging for extended periods at 190°C did not alter the composition or morphology of the insoluble particles.MST/661

Insoluble phase in Al–1·52Cu–0·75Mg alloys containing silicon

Abstract Insoluble particles present in solution treated, quenched and aged Al–1·52Cu–0·75Mg alloys containing 0·23, 0·49, 0·76, and 1·03 wt-% Si have been investigated. Back-scattered scanning electron microscope images of polished sections of the alloys showed the presence of very small, nearly spherical particles at the grain boundaries of all alloys except that containing 0·23 wt-% Si. Alloys with 0·76 and 1·03 wt-% Si also contained large particles of well defined geometrical shapes. An electrolytic technique was used to extract the insoluble particles from the matrix. The extracted particles were analysed by energy dispersive X-ray analysis in a scanning electron microscope. They contained 20·6±0·4%Cu, 32·6±0·4%Mg, 30·2±0·4%Si, and 16·6±0·1%Al (all wt-%). X-ray diffraction analysis of these particles showed that they have a hexagonal structure with lattice parameters a=1·036±0·004 nm and c=0·404±0·004 nm. The insoluble particles were identified as quarternary phase Q. Aging for extended periods at 1...