Cavity generation in dental enamel using a copper-HyBrID laser.

Applications of Cu-HyBrID laser (copper laser with Hydrogen Bromide In Discharge) in Dentistry and AFM (atomic force microscopy) evaluations of dental tissues irradiated by laser are seldom reported in the literature. This work presents an AFM investigation of the cross-section of a cavity generated in human dental enamel by laser thermal evaporation using the Cu-HyBrID laser. The results exposed the structural and morphological differences between the fused and non-fused dental enamel, provide qualitative information about the susceptibility of these tissues to abrasive polishing, and revealed the extension of the thermal damage. Quantitative information concerning the wall thickness and the dimensions of the cross-section of non-fused enamel rod were also obtained.

Extracellular matrix (ECM) microstructural composition regulates local cell-ECM biomechanics and fundamental fibroblast behavior: a multidimensional perspective.

The extracellular matrix (ECM) provides the principal means by which mechanical information is communicated between tissue and cellular levels of function. These mechanical signals play a central role in controlling cell fate and establishing tissue structure and function. However, little is known regarding the mechanisms by which specific structural and mechanical properties of the ECM influence its interaction with cells, especially within a tissuelike context. This lack of knowledge precludes formulation of biomimetic microenvironments for effective tissue repair and replacement. The present study determined the role of collagen fibril density in regulating local cell-ECM biomechanics and fundamental fibroblast behavior. The model system consisted of fibroblasts seeded within collagen ECMs with controlled microstructure. Confocal microscopy was used to collect multidimensional images of both ECM microstructure and specific cellular characteristics. From these images temporal changes in three-dimensional cell morphology, time- and space-dependent changes in the three-dimensional local strain state of a cell and its ECM, and spatial distribution of beta1-integrin were quantified. Results showed that fibroblasts grown within high-fibril-density ECMs had decreased length-to-height ratios, increased surface areas, and a greater number of projections. Furthermore, fibroblasts within low-fibril-density ECMs reorganized their ECM to a greater extent, and it appeared that beta1-integrin localization was related to local strain and ECM remodeling events. Finally, fibroblast proliferation was enhanced in low-fibril-density ECMs. Collectively, these results are significant because they provide new insight into how specific physical properties of a cell's ECM microenvironment contribute to tissue remodeling events in vivo and to the design and engineering of functional tissue replacements.

[Pharyngeal and laryngeal hamartoma: case report]. / Amartoma faringolaringeo.

In this report a case of laryngeal hamartoma is presented. Macroscopically this lesion is quite similar to a tumor but is actually a malformation derived from an error in the development of a healthy organ. Histologically, the hamartoma is composed of a proportionally abnormal mixture of tissues as compared to what is normally present in its anatomic site. The lesion is extremely rare and usually appears in the head and neck district, spleen, pancreas, lung and liver. The diagnosis is essentially based on histological examination. The treatment of choice consists of surgery and periodic follow-up. Differential diagnosis must consider other rare neoplasms such as rhabdomyoma and teratoma.