Expiration Date Effect on Mechanical and Chemical Properties of Glass Ionomer Cements

ABSTRACT: The glass ionomer cements (GICs) is a generic name given to a group of materials widely used in clinical dentistry which if used after the specified expiration date, material properties may be affected. to evaluate the Vick ers microhardness, surface morphology and the energy dispersive X-ray microanalysis (EDX), of GICs with different expiration dates that were stored at room temperature. specimens of highly viscous glass ionomer cement (HVGIC) (Ketac Cem and Ketac Molar) and resin-modified glass ionomer cement (RMGIC) (Vitrebond) with different expiration dates (current, close to their expiration and expired) were prepared for Vickers microhardness test and scanning electronic microscopy (SEM) with EDX, measuring 5 mm in diameter and 2 mm length, per the manufacturer's instructions, in standard cylindrical teflon molds. For the comparison of obtained values, the ANOVA test was used, while Tukey test was used for the multiple comparisons. In all the GICs used, the microhardness decreased as the expiration date approached, finding a significant statistical differen ce (P<0.05) in Ketac Molar and Vitrebond. SEM sample analysis revealed similar cohesive cracks in all tested materials. The EDX analysis revealed the presence of the elements F, Al and Si in all GICs and Ca only in Ketac Molar and Ketac Cem. The elements were found in a higher atomic percentage in the GICs with an current date and in a lower percentage in those with an expired date. HVGIC and RMGIC with an expiration date finish and that were stored at room temperature, suffer significant physical and chemical changes, which could put doubts its clinical effectiveness.

RESUMEN: El cemento de ionómero de vidrio (CIV) es un nombre genérico que se le da a un grupo de materiales ampliamente utilizados en odontología clínica que si se usan después de la fecha de vencimiento especificada, las propiedades del material pueden verse afectadas. evaluar la microdureza Vickers, la morfología superficial y el microanálisis de energía dispersa de rayos X (EDX), de CIV con diferentes fechas de caducidad almacenados a temperatura ambiente. Muestras de cemento de ionómero de vidrio de alta viscosidad (CIVAV) (Ketac Cem y Ketac Molar) y cemento de ionómero de vidrio modificado con resina (CIVMR) (Vitrebond) con diferentes fechas de vencimiento (vigente, próximo a su vencimiento y vencido) de 5 x 2 mm, fueron preparadas para microscopía electrónica de barrido (MEB) con EDX y microdureza Vickers, según las instrucciones del fabricante, en moldes de teflón cilíndricos estándar. Para la comparación de los valores obtenidos se utilizó la prueba ANOVA, mientras que para las comparaciones múltiples se utilizó la prueba de Tukey. En todos los CIV utilizados, la microdureza disminuyó a medida que se acercaba la fecha de vencimiento, encontrándose una diferencia estadística significativa (P <0.05) en Ketac Molar y Vitrebond. El análisis de la muestra en MEB reveló grietas cohesivas similares en todos los materiales probados. El análisis EDX reveló la presencia de los elementos F, Al y Si en todos los GIC y Ca solo en Ketac Molar y Ketac Cem. Los elementos se encontraron en mayor porcentaje atómico en los GIC con fecha vigente y en menor porcentaje en aquellos con una fecha vencida. Los CIVAV y CIVMR con fecha de caducidad vencida y que fueron alma- cenados a temperatura ambiente, sufrieron cambios físicos y químicos importantes, lo que podría poner en duda su efectividad clínica.

Compliance Policy for Expiration Date of Repackaged Drugs in America and Its Enlightenments for China / 中国药房

OBJECTIVE:To provide references and suggestions for expiration date management of dismounted drugs in China.METHODS:The main contents about compliance policy for expiration date of repackaged drugs in America were summarized.The current situation and problems of expiration date management of dismounted drugs in China were analyzed to provide suggestions for standardizing expiration date management of dismounted drugs in China.RESULTS & CONCLUSIONS:The compliance policy for expiration date of repackaged drugs in America contain determination principle of expiration date of repackaged drugs,repackaged container standard,etc.In contrast,the expiration date management of dismounted drugs in China is lack of specific standards and requirements;major issues are as follows as the concept of expiration date of dismounted drugs is ambiguous and container management is not standardized.It is suggested that relevant departments can refer to compliance policy for expiration date of repackaged drugs in America,define the method of determining the expiration date of the dismounted drugs,and standardize the standards and management of packaging containers so as to standardize expiration date management of dismounted drugs in China practically.

Methods for determining expiration date of in vitro diagnostic medical device and significance for signing expiration date / 医疗卫生装备

Objective To explore the common methods for determining the expiration rate of the in vitro diagnostic medical device and the significance for signing the expiration date.Methods The methods for determining the expiration date were analyzed based on the features of the in vitro diagnostic medical device and Regulations for Medical Devices Registration and Management.Results The methods estimated the expiration date effectively,while the expiration date had to be monitored and calibrated in time according to risk management principle.Conclusion The safety and efficiency of the in vitro diagnostic medical device are enhanced by signing the expiration date in the technical manual and label.

Methods for determining expiration date of in vitro diagnostic medical device and significance for signing expiration date / 医疗卫生装备

Objective To explore the common methods for determining the expiration rate of the in vitro diagnostic medical device and the significance for signing the expiration date.Methods The methods for determining the expiration date were analyzed based on the features of the in vitro diagnostic medical device and Regulations for Medical Devices Registration and Management.Results The methods estimated the expiration date effectively,while the expiration date had to be monitored and calibrated in time according to risk management principle.Conclusion The safety and efficiency of the in vitro diagnostic medical device are enhanced by signing the expiration date in the technical manual and label.

Observation on expiration date and disinfectant efficacy of an alcohol-based hand disinfectant / 中国感染控制杂志

Objective To understand the expiration date of alcohol-based hand disinfectant after it is opened for use,and provide reference for rational clinical application of alcohol-based hand disinfectant.Methods 20 bottles of the same brand alcohol-based hand disinfectant which opened at the same time by the clinical departments were selected as the study object,hand hygiene compliance in theses departments ranked fourth from the end in the hospital,specimens were taken on the first day after opening,and repeated every 10 days until the disinfectant was used up.Hand specimens were also taken after disinfected by disinfectant.Qualified condition of disinfectant and hand specimens was detected.Results A total of 98 disinfectant specimens were collected,by naked eye observation,20 bottles of alcohol-based hand disinfectant were free of discoloration,precipitation,and suspended matter during the whole study period.The qualified detection rates of alcohol-based hand disinfectant within 60 days after opening were all 100%.44 hand specimens were taken and detected after disinfection,3 of which were unqualified(all were disinfected by alcohol-based hand disinfectant 50 days after opening),then detected again after disinfected by the same batch of disinfectant,all were qualified,which suggested that unqualified detection result of hand specimens was not due to disinfectant.Conclusion Alcohol-based hand disinfectant still has a good bactericidal effect on the sixth day after opening.

Predicting expiration date of torasemide injection by classical constant-tempera-ture experiment / 药学实践杂志

Objective To investigate the stability of torasemide injection and predict its expiration date in room temperatue .Methods The contents of torasemide were determined by HPLC .The expiration date was predicted by classical constant-temperature experiment .Results The contents of torasemide degradation with time according to a first order reaction at room temperature (25 ℃) .The disintegration rate constant K was K25 ℃ =5 .186 9 × 10-6 h-1 and the expiration date of to-rasemide injection was t0 .9 =2 .32 years .Conclusion The torasemide injection expiration date was tentatively scheduled for two years .

<b>Necessity of Precautions Against Expired and Broken Press Tack Needle</b> / 日本東洋医学雑誌

In Japan, controlled devices for medical professionals have been often purchased by people other than acupuncturists or doctors, using the Internet sales system. Press Tack Needle (PYONEX^®) allows easy handling by combining a plastic part with an adhesive tape. Since it has been reported to be relatively safe with limited adverse events such as adhesive-related dermatitis or similarly mild disorders, it is widely used. We report a case that when the patient removed a PYONEX^® which applied by himself, the needle tip was broken and remained in his body. It might lead to an accident such as injury due to a broken needle left in the body. The patient had purchased the PYONEX^® on his own judgments, storing it for a long period of time, applied it to his body 10 months after its expiration date and kept it attached for approximately 3 weeks. Plastics are characterized by deterioration and can be damaged by environmental factors including ultraviolet rays, water, and shocks. In this paper as an urgent issue, we note that when using these products, in addition to paying attention to their expiration dates, precautions should be considered since deterioration may also progress due to prolonged attachment.

Atualidade de Vigotski / Vygotsky in present days

No presente texto, discute-se a atualidade da teoria histórico-cultural elaborada por Lev Semionovitch Vigotski entre, aproximadamente, o final da segunda década e a terceira década dos anos de 1900. Adota-se atitude crítica em relação à ideia de que o conhecimento científico tem prazo de validade, procurando-se mostrar que ela decorre do processo de transformação da ciência em mercadoria. Como um contraponto a essa visão, argumenta-se que todo artifício construído pelo homem apresenta algo de permanente, quando transcende a mera funcionalidade das coisas produzidas para consumo. Ou, dizendo em outros termos, tudo o que é singular, de certa forma, tem permanência no mundo

In this paper, we discuss the topicality of the cultural-historical theory developed by Lev Semionovitch Vygotsky approximately between the end of the second decade and the third decade of the 20th century. We adopt a critical attitude towards the idea that scientific knowledge has an expiration date, and we seek to show that this idea emerges from the transformation of science into a commodity. As a counterpoint to this view, we argue that every device built by man presents something permanent which transcends the mere functionality of things produced for consumption. In other words, we argue that anything that is singular, in a way, has permanence in the world

Stability and Expiration Date Prediction of Betamethasone Cream / 中国药房

OBJECTIVE:To study the stability and to predicate the expiration date of betamethasone cream.METHODS:The HPLC method was used to determination the content of betamethasone,the stability test of cream was done by initial mean velocity method and strong light exposure experiment,respectively.RESULTS:The linear concentration range for betametha?sone cream was0.25～8?g/ml(r=0.9991),the average recovery rate was98.56%,RSD=0.78%;The content was highly correlated to temperature,whereas on which the light exposure did little effect.CONCLUSIONS:Betamethasone cream should be stored under room temperature and in a cool place,it is predicted that the expiration date of betamethasone cream is1year.