A comparison study of periapical repair in dogs` teeth using RoekoSeal and AH plus root canal sealers: A histopathological evaluation

The objective of the study was to evaluate the biocompatibility of RoekoSeal sealer Roeko (Dental Products, Langenau, Germany) with the periapical tissues of dogs and compare it with AH Plus sealer (Dentsply/De Trey, Konstanz, Germany). The pulps of 32 root canals were removed, the apical cementum layer perforated, the biomechanical preparation performed, and the root canals filled by lateral condensation technique. Ninety days after the surgery, the animals were euthanized, the bone with teeth removed, and the samples prepared for histopathological analysis. In group 1 (RoekoSeal Automix), deposition of mineralized tissue was observed, with complete newly mineralized apical formed tissue in 43.8% and partial sealing in 56.2%. In group 2 (AH Plus), in 12.5% there was complete newly mineralized apical formed tissue, in 75% the sealing was partial, and in 12.5% there was no sealing (p < 0.05). There were no differences between the groups in relation to the inflammatory infiltrate; thickness of the periodontal ligament; and the resorption of dentin, cementum or bone (p > 0.05).

Histomorphologic evaluation of Ti-13Nb-13Zr alloys processed via powder metallurgy. A study in rabbits

This study presents the in-vivo evaluation of Ti-13Nb-13Zr alloy implants obtained by the hydride route via powder metallurgy. The cylindrical implants were processed at different sintering and holding times. The implants` were characterized for density, microstructure (SEM), crystalline phases (XRD), and bulk (EDS) and surface composition (XPS). The implants were then sterilized and surgically placed in the central region of the rabbit`s tibiae. Two double fluorescent markers were applied at 2 and 3 weeks, and 6 and 7 weeks after implantation. After an 8-week healing period, the implants were retrieved, non-decalcified section processed, and evaluated by electron, UV light (fluorescent labeling), and light microscopy (toluidine blue). BSE-SEM showed close contact between bone and implants. Fluorescent labeling assessment showed high bone activity levels at regions close to the implant surface. Toluidine blue staining revealed regions comprising osteoblasts at regions of newly forming/formed bone close to the implant surface. The results obtained in this study support biocompatible and osseoconductive properties of Ti-13Nb-13Zr processed through the hydride powder route. (c) 2007 Published by Elsevier B.V.

HISTOLOGIC EVALUATION OF END-TO-SIDE NEURORRHAPHY. EXPERIMENTAL STUDY IN RATS

Objective: The aim of this study was to histologically compare the axonal sprouting after end-to-side neurorrhaphy with or without epineurotomy. Methods: twenty male Wistar rats were used, divided into two groups of 10 rats each. A 1.0cm segment of the tibial nerve E was dried and sutured on the opposite side, where it was sutured into the sciatic nerve D. In Group I, the suture was made directly in the epineurium and in Group II, epineurotomy was performed. After 4 weeks, histological evaluation was carried out of the transposed segment and the sciatic nerve distal to the suture. Results: the results showed a small number of remyelinated fibers, varying from 7 to 51 fibers in Group I and from 10 to 91 fibers in Group II. The Mann-Whitney U test was used, with p=0.311, showing there is no statistically significant difference between the two groups. There was no positive relation between the number of remyelinated fibers in the graft and in the suture site distal to the sciatic lesion. Conclusion: lateral-ending neurorrhaphy, with or without epineural window, does not promote efficient remyelinization. Level of Evidence: Level II, prospective comparative study.

Evaluation of uranium incorporation from contaminated areas using teeth as bioindicators - a case study

The Southwest region of the Bahia state in Brazil hosts the largest uranium reserve of the country (100 kton in uranium, only), plus the cities of Caetite, Lagoa Real and Igapora. In this work, aim was at the investigation of uranium burdens on residents of these cities by using teeth as bioindicators, as a contribution for possible radiation protection measures. Thus, a total of 41 human teeth were collected, plus 50 from an allegedly uranium free area (the control region). Concentrations of uranium in teeth from residents of 5- to 87-y old were determined by means of a high-resolution inductively coupled plasma mass spectrometer (ICP-MS). The highest uranium concentration in teeth was measured from samples belonging to residents of Caetite (median equal to 16 ppb). Assuming that the uranium concentrations in teeth and bones are similar within 10-20% (for children and young adults), it concluded that uranium body levels in residents of Caetite are at least one order of magnitude higher than the worldwide average. This finding led to conclude that daily ingestion of uranium, from food and water, is equally high.

Study of absorption spectrum and dynamics evaluation of the indocyanine-green first singlet excited state

Excited state absorption and excited state dynamics of indocyanine-green (ICG) dissolved in dymethyl sulfoxide were measured using white-light continuum Z-scan (WLCZScan) and white-light continuum pump-probe (WLCPP) techniques. The excited state absorption spectrum, obtained through Z-scan measurements, revealed saturable absorption (SA) for wavelengths longer than 630 nm, while reverse saturable absorption (RSA) appeared, as indicated by a band at approximately 570 nm. Both processes were modeled by a three-energy-level diagram, from which the excited state cross-section values were determined. SA and RSA were also observed in pump-probe experiments, with a recovery time in the hundreds of picoseconds time scale due to the long lifetime of the first excited state of ICG. Such results contribute to the understanding of ICG optical properties, allowing application in photonics and medicine. Copyright (C) 2010 John Wiley & Sons, Ltd.

Evaluation of dental pulp repair using low level laser therapy (688 nm and 785 nm) morphologic study in capuchin monkeys

The aim of this study was to evaluate the hypothesis that low-level laser therapy (LLLT) 688 nm and 785 nm accelerate dentin barrier formation and repair process after traumatic pulp exposure. The sample consisted of 45 premolars of capuchin monkeys (Cebus apella) with pulp exposure Class V cavities. All premolars were treated with calcium hydroxide (Ca(OH)(2)), divided in groups of 15 teeth each, and analyzed on 7(th), 25(th), and 60(th) day. Group GI - only Ca(OH)(2), GIF- laser 688 nm, and GIII - laser 785 nm. Laser beam was used in single and punctual dose with the parameters: continuous, 688 nm and 785 nm wavelength, tip`s area of 0.00785 cm(2), power 50 mW, application time 20 s, dose 255 J/cm(2), energy 2 J. Teeth were capped with Ca(OH)(2), Ca(OH)(2) cement and restored with amalgam. All groups presented pulp repair. On 25(th) day the thickness of the formed dentin barrier was different between the groups GI and GII (p < 0.05) and between groups GI and GIII (p < 0.01). On 60(th) day there was difference between GI and GIII (p < 0.01). It may be concluded that, LLLT 688 nm and 785 nm accelerated dentin barrier formation and consequently pulp repair process, with best results using infrared laser 785 nm. (c) 2009 by Astro Ltd. Published exclusively by WLLEY-VCH Verlag GmbH & Co. KGaA