RESUMEN
OBJECTIVE: The aim of this in vitro study was to evaluate the effect of an oxide nanocoating to prevent colour degradation of maxillofacial silicone elastomers following accelerated ageing. MATERIAL AND METHODS: Specimens (N = 40) of specified dimensions were fabricated in Factor II room temperature vulcanizing (RTV) silicone and processed according to the manufacturer's instructions. Two groups were classified with 20 specimens each. Specimens in the first group were coated with titanium dioxide (TiO2) by atomic layer deposition technology. The colour stability test was conducted with a UV-VIS spectrometer (Schimadzu) for both titanium dioxide nanocoated and uncoated specimen groups after subjecting them to accelerated ageing. It was analysed using the CIE L*a*b method. RESULTS: The average colour change was highest for uncoated specimens (2.868), and the average colour change for titanium dioxide-coated specimens was significantly low (1.774). The average colour change of uncoated specimens (2.868) was close to the acceptable threshold value (3), and that of coated specimens (1.774) was far below the acceptable threshold (3). CONCLUSIONS: The colour change that occurred in titanium dioxide nanocoated specimens following accelerated ageing was significantly lower than that in the uncoated group, showing that the TiO2 nanocoating was effective in reducing the colour degradation of silicone elastomers. CLINICAL RELEVANCE: Maxillofacial prostheses fabricated from silicone elastomers go through undesirable colour degradation over time. The development of a scientific technique that retards the colour deterioration of silicone prostheses would be of great clinical significance.
Asunto(s)
Elastómeros de Silicona , Color , Temperatura , Ensayo de MaterialesRESUMEN
Cerebral palsy is often associated with spasticity. This study was designed to evaluate the effect of oral baclofen in hypertonic neonates. Retrospective chart review of patients treated with oral baclofen (identified by means of pharmacy records) during a 3-year period was undertaken. Data on muscle tone evaluated using the Modified Ashworth Scale scores were analyzed for effectiveness. Twenty-nine infants had Modified Ashworth Scale scores before and during oral baclofen therapy. The study infants had a mean gestational age of 25.7 ± 1.9 weeks. Baclofen was started at a postnatal age of 86.4 ± 33.6 days. Comparison of Modified Ashworth Scale scores after initiation of therapy to prebaclofen scores demonstrated no significant decrease in muscle tone. Results of our study show that there is no overall decrease in tone during oral baclofen therapy in hypertonic preterm neonates.