Evaluation of Strength of Different Resin Materials Used in Overdenture

Introduction: Finding a suitable material that could be used to restore relatively small inter-arch spaces in which reasonable aesthetics as well as good functional strength could be achieved is a difficult process that requires good understanding of the clinical situation and precise management. Historically Metal used to offer the smallest possible thickness with excellent strength but lacks resiliency with poor aesthetics. Aim of the study: This In-vitro study was conducted to compare two different aesthetic materials PEEK and ACETAL regarding their mechanical strength when used as Overdenture framework in a relatively small thickness. Material and Methods: 120 specimens were prepared according to the American Society for Testing and Materials (ASTM) International standards and divided into two main groups according to the material, group (A) PEEK samples and group (B) ACETAL samples. Each group of 60 specimens was subdivided into three different groups (I, II, III) according to three different thicknesses (1, 1.5 and 2 mm). Each group contains 20 identical samples, half of them were subjected to water absorption and the other half were left untouched. Then all specimens were loaded to failure in a Universal Testing Machine (UTM). Results: Data analyzed using Student’s t test for independent samples and showed that any increase in thickness lead to increase in the flexural strength which was proportioned in all Acetal samples in contrast to PEEK samples. All PEEK samples recorded significantly higher flexural strength values on every thickness than Acetal samples. Acetal samples with 2 mm of thickness did not offer enough strength as suggested by the international standards for polymer materials and ISO. Conclusions: The flexural strength of PEEK samples was 3 times higher than Acetal samples. Acetal thickness should be more than 2mm. water has a significant effect on the strength of Acetal material

Liver fibrosis: consensus recommendations of the Asian Pacific Association for the Study of the Liver (APASL)

Liver fibrosis is a common pathway leading to cirrhosis, which is the final result of injury to the liver. Accurate assessment of the degree of fibrosis is important clinically, especially when treatments aimed at reversing fibrosis are being evolved. Liver biopsy has been considered to be the “gold standard” to assess fibrosis. However, liver biopsy being invasive and, in many instances, not favored by patients or physicians, alternative approaches to assess liver fibrosis have assumed great importance. Moreover, therapies aimed at reversing the liver fibrosis have also been tried lately with variable results. Till now, there has been no consensus on various clinical, pathological, and radiological aspects of liver fibrosis. The Asian Pacific Association for the Study of the Liver set up a working party on liver fibrosis in 2007, with a mandate to develop consensus guidelines on various aspects of liver fibrosis relevant to disease patterns and clinical practice in the Asia-Pacific region. The process for the development of these consensus guidelines involved the following: review of all available published literature by a core group of experts; proposal of consensus statements by the experts; discussion of the contentious issues; and unanimous approval of the consensus statements after discussion. The Oxford System of evidence-based approach was adopted for developing the consensus statements using the level of evidence from 1 (highest) to 5 (lowest) and grade of recommendation from A (strongest) to D (weakest). The consensus statements are presented in this review

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population