Shelf Life and Storage Conditions of Universal Adhesives: A Literature Review.

This paper presents state of the art universal adhesive systems and the effect of shelf-life and storage conditions on their bond performance. Three topics are explored in this review: an introduction to the topic, the mechanisms responsible for the degradation of the hybrid layer, and the factors that play a role in the stability of universal adhesives. In addition, issues such as potential durability and clinical importance are discussed. Universal adhesive systems are promising but must be handled and stored according to the manufacturer's instructions, with careful attention given to the details of shelf-life and storage conditions for maximal success. It appears that the components of universal adhesives play an important role in their stability. Furthermore, HEMA-free formulations using methacrylamides lead to longer shelf-life. Further research is needed to prove these hypotheses.

Analysis of vaccine losses by temperature changes in a Health Region from Minas Gerais State, Brazil / Análise das perdas vacinais por alteração de temperatura em Região de Saúde do Estado de Minas Gerais, Brasil

INTRODUCTION: Immunobiologicals are of great importance for the prevention and eradication of diseases. However, the lack of maintenance of the cold chain generates several problems related to losses of these substances, burdening an important amount of public resources. OBJECTIVE: To analyze vaccine losses in a Health Region (Região Ampliada de Saúde Oeste) of Minas Gerais State in Brazil. METHODS: This is a descriptive study, based on secondary data obtained through forms used by the regional health agency (Superintendência Regional de Saúde, SRS), to register losses of immunobiologicals due to temperature changes. Forms from February 2016 through January 2018 were analyzed. The data was organized and validated by double typing. RESULTS: Vaccine losses were caused by lack of electrical energy (40.83%), followed by equipment failure (36.67%), and professional error (10%). As a consequence, 17,229 bottles of vaccines (65.78%) were discarded, corresponding to 111,145 doses. The financial loss was R$ 604,340.31. CONCLUSION: Losses of vaccines due to temperature changes were relevant in the studied region, damaging the budget for the local health network. Therefore, it is suggested that measures to minimize these losses should be adopted.

INTRODUÇÃO: Os imunobiológicos são de grande importância para a prevenção e erradicação de doenças. Entretanto, a falta de manutenção da Rede de Frio gera diversos problemas relacionados a perdas dessas substâncias, onerando uma importante quantia de recursos públicos. OBJETIVO: Analisar as perdas vacinais da Região Ampliada de Saúde Oeste de Minas Gerais. MÉTODOS: Trata-se de um estudo descritivo, com base em dados secundários obtidos através de formulários utilizados pela Superintendência Regional de Saúde (SRS), para avaliação de perdas de imunobiológicos por alteração de temperatura. Foram analisados os formulários de fevereiro de 2016 até janeiro de 2018. Os dados foram organizados e validados por dupla digitação, e a análise foi feita descritivamente. RESULTADOS: Os resultados mostraram que dos motivos das ocorrências 40,83% foram por falta de energia elétrica, seguida de falha no equipamento (36,67%), e erro do profissional (10%). Foram inutilizados 17229 frascos de vacinas (65,78%), sendo 111.145 doses, com uma perda financeira de R$ 604.340,31. CONCLUSÃO: Identificou-se que as perdas físicas por alteração de temperatura de vacinas na região estudada foram relevantes, gerando prejuízos para o orçamento do SUS. Dessa forma sugere-se a adoção de condutas para minimizar estas perdas.

Preservação de ovos de helmintos e cistos de protozoários em iodo-mercurato de potássio. Revisitando experimentos realizados há cerca de 40 anos / Preservation of helminth eggs and protozoan cysts in potassium iodine-mercurate. Revisiting experiments carried out about 40 years ago

Foi realizada reavaliação sobre o estado de preservação de ovos de helmintos e cistos de protozoários mantidos por cerca de 40 anos em solução de iodo‑mercurato de potássio a 0,2%. Foi observado que ovos de Schistosoma mansoni, Ancylostomidae e Trichuris trichiura e oocistos de Isospora belli mantiveram‑se em condições adequadas para a sua identificação ao microscópio ótico comum. No material examinado, foi possível verificar a presença de miracídio em ovo de Schistosoma mansoni, forma larvada em ovo de T. trichiura e esporozoitos em oocistos de I. belli.

A reassessment was carried out on the preservation status of helminth eggs and protozoan cysts maintained for about 40 years in 0.2% potassium iodine‑mercurate solution. It was observed that Schistosoma mansoni, Ancylostomidae and Trichiuris trichiura eggs and Isospora belli oocysts were kept in conditions suitable for their identification under a common light microscope. In the examined material, it was possible to verify the presence of miracidium in S. mansoni egg, larvae in T. trichiura egg and sporozoites in I. belli oocysts.

Mechanical properties of composites as functions of the syringe storage temperature and energy dose

Objective: To investigate the mechanical properties of different classifications of composites indicated for posterior application as functions of the storage condition and of the energy dose. Material and Methods: Specimens (8x2x2 mm) were obtained according to the factors: I) Composites (3M ESPE): Filtek P60, Filtek Z350XT, and Filtek Silorane; II) Syringe storage conditions: room temperature, aged, oven, refrigerator, and freezer; and III) Energy dose: 24 J/cm2 and 48 J/cm2. After photoactivation, the specimens were stored at 37ºC for 24 h. After storage, a three-point bending test was carried out in a universal testing machine at 0.5 mm/min. Flexural strength (S) and flexural modulus (E) were calculated. Data were analyzed by three-way ANOVA and Tukey's test (α=0.05). Results: Different storage conditions significantly affected the silorane composite for S; conversely, no effects were noted in terms of E. The accelerated aging protocol significantly increased the S of Filtek P60 and Filtek Silorane, whereas storage in the oven significantly decreased the S for all of the composites tested. Filtek P60 was the only composite not affected by the lower storage temperatures tested for S, whereas for the silorane this parameter was impacted at the same conditions. The factor "dose" was not statistically significant. Conclusions: The syringe storage at different temperature conditions proved to influence mostly the flexural strength, a clinically important characteristic considering the posterior indication of the materials tested. The silorane composite should not be stored at lower temperatures. .