Treatment of Atrophic Ridges with Titanium Mesh: A Retrospective Study Using 100% Mineralized Allograft and Comparing Dental Stone Versus 3D-Printed Models.

This multicenter study retrospectively evaluated implant survival and bone growth in atrophic ridges that were augmented with titanium mesh and 100% mineralized solvent-dehydrated bone allografts (MSDBA). A secondary objective of this study was to evaluate differences in outcomes by diagnostic model type. Titanium mesh was shaped on a diagnostic wax-up of the patient's jaw: Twenty-three patients (Group 1) had wax-ups on dental stone models, and 16 patients (Group 2) had wax-ups on models fabricated with three-dimensional (3D) printing technology. Clinical and histologic data were analyzed. The average bone gain ranged from 5.94 to 6.91 mm horizontally and 5.76 to 6.99 mm vertically and was not significantly different between the two model groups (P > .05). Implant survival was 100% after 18 to 48 months. Although model type had no significant influence on outcomes, 3D-printed models allowed for faster surgery and served as visual aids for patient education.

Clara-cell hyperplasia after quartz and coal-dust instillation in rat lung.

Bronchiolo-alveolar hyperplasia of type II cells in rat lungs after particle exposure is a well-known preneoplastic lesion. The Clara cell, stem cell of the bronchiolar epithelium and the main carrier of cytochrome P-450 isoenzyme system in the lung, has barely been evaluated with regard to this effect. The aim of this study was to examine Clara-cell hyperplasia after particle exposure and to characterize cell proliferation and its normal function. Female Wistar rats were intratracheally instilled with coal dust samples of variable quartz content, quartz (DQ12), titanium dioxide, or saline solution containing 0.5% Tween 80. After 126-129 wk, all coal mine dust- and quartz-exposed animals developed Clara-cell hyperplasia: up to 0.48% of the total lung area, which was significantly increased compared to titanium dioxide (p <.05) and control (p <.03) animals. Proliferation and hyperplasia of bronchiolar Clara cells by coal dusts was independent of their quartz content. The lack of proliferating cell nuclear antigen staining in most of the hyperplastic Clara cells suggests that following damage of alveolar epithelial cells, Clara cells migrate in and remodulate the alveolar epithelium. After the migration they keep their function in the xenobiotic metabolism, as shown by expansion of CYP2E1 active Clara cells. The minor development of Clara-cell hyperplasia in titanium dioxide-treated rats indicates that this is not a general particle effect, and is possibly due to its lower toxicity to epithelial cells.

Life cycle benefits.

Life cycle benefits are designed to meet the needs of employees throughout the stages of life. Many employers in both the public and private sectors are finding that this approach to benefits makes sense from a number of perspectives.

Combined use of autoradiography and enzyme histochemistry in studies on the mammalian testis.

Combined application of the methods of enzyme histochemistry and of autoradiography in one and the same section of tissue provides a method to achieve further informations on the individual cells. Prespermatogenesis and spermatogenesis in rodents with their well defined steps of development and very specific enzymatic patterns of each of the stages of the cycle of the seminiferous epithelium were used as a model to study the double labelling with the aid of the enzyme reaction and labelling with 3-H-thymidine. The techniques applied in this study are described and discussed in detail. Possibilities to elucidate the regeneration mode of the seminiferous epithelium by means of this method are discussed.