Evaluation of New Alkasite Based Restorative Material for Restoring Non- Carious Cervical Lesions- Randomized Controlled Clinical Trial.

Two different restoration materials, an alkasite-based resin composite and a resinmodified glass ionomer cement were used to assess restoration of non-carious cervical dental lesions. This split mouth randomized controlled trial included 40 patients. After randomization both sides of the dental arch were restored with either an alkasite-based (Cention N, Ivoclar Vivadent) or a resin-modified glass ionomer cement (Voco GmbH) restoration. The placed fillings were evaluated by blinded additional operators 1, 6 months and 1 year after to the USPHS criteria (retention, marginal integrity and discoloration, anatomical form and secondary caries). Data were analyzed using Kendall's Coefficient of Concordance test and Chi-square tests using SPSS software (SPSS Inc., Version 20) (P=0.05). As for retention and anatomic form both materials performed similar after one month. However, the retention and anatomic form for alkasite based restorative Cention showed significantly better results after 6 months (p=0.013/p=0.003) and one year (p=0.026/p=0.008). The resin modified glass ionomer restoration showed higher discoloration after 6 months (p=0.025) and one year (p=0.018), while Cention performed better regarding marginal integrity at all time intervals. No secondary caries occurred. Alkasite based restorative materials displayed superior technical, mechanical and aesthetical performance in a follow-up period of one year and can therefore be recommended as an alternative to resin-modified glass ionomer cements.

MMP-9 Levels and NaOCl Lavage in Randomized Trial on Direct Pulp Capping.

Outcome expectations of direct pulp capping in carious teeth are obscured by a clinically unknown infiltration and breakdown of the dental pulp tissue. Histologic studies showed that this soft tissue breakdown is related to the innate immune system. We hypothesized 1) that a neutrophil biomarker could predict the outcome of direct pulp capping and 2) that using sodium hypochlorite (NaOCl) as a lavage solution to remove necrotized infected pulp tissue could improve it. In this randomized trial in mature posterior teeth causing no or mild discomfort with carious pulpal exposures, pulpal fluid was collected to assess neutrophil gelatinase (matrix metalloproteinase 9 [MMP-9]) per total protein (TP) levels as a predictive local biomarker. Subsequently, the dentin-pulp wound was randomly washed with a 2.5% NaOCl or a physiologic saline solution (1:1 allocation), capped with mineral trioxide aggregate, and the tooth was immediately restored with a resin-based composite restoration. Ninety-six patients were included, and 84 individuals could be followed up to treatment failure or clinically confirmed pulp survival after a minimum of 1 y. The entire data were fitted to a Cox proportional hazards model to assess the influence of the observational variables MMP-9/TP and discomfort with the randomized lavage treatment on pulp survival. The Kaplan-Meier pulp survival rates after 1 y were 55% for saline and 89% for NaOCl lavage. The inflammatory state of the pulp tissue as reflected by MMP-9/TP levels and NaOCl lavage had a highly significant (P < 0.001 and P = 0.004, respectively) impact on pulp survival, while mild preoperative discomfort did not. In conclusion, MMP-9/TP showed great promise as a predictive local biomarker, and NaOCl lavage considerably improved the survival time of cariously exposed and directly capped pulps.

Novel method to identify source-associated phylogenetic clustering shows that Listeria monocytogenes includes niche-adapted clonal groups with distinct ecological preferences.

While phylogenetic and cluster analyses are often used to define clonal groups within bacterial species, the identification of clonal groups that are associated with specific ecological niches or host species remains a challenge. We used Listeria monocytogenes, which causes invasive disease in humans and different animal species and which can be isolated from a number of environments including food, as a model organism to develop and implement a two-step statistical approach to the identification of phylogenetic clades that are significantly associated with different source populations, including humans, animals, and food. If the null hypothesis that the genetic distances for isolates within and between source populations are identical can be rejected (SourceCluster test), then particular clades in the phylogenetic tree with significant overrepresentation of sequences from a given source population are identified (TreeStats test). Analysis of sequence data for 120 L. monocytogenes isolates revealed evidence of clustering between isolates from the same source, based on the phylogenies inferred from actA and inlA (P = 0.02 and P = 0.07, respectively; SourceCluster test). Overall, the TreeStats test identified 10 clades with significant (P < 0.05) or marginally significant (P < 0.10) associations with defined sources, including human-, animal-, and food-associated clusters. Epidemiological and virulence phenotype data supported the fact that the source-associated clonal groups identified here are biologically valid. Overall, our data show that (i) the SourceCluster and TreeStats tests can identify biologically meaningful source-associated phylogenetic clusters and (ii) L. monocytogenes includes clonal groups that have adapted to infect specific host species or colonize nonhost environments.

Rapid prototyping of pulse oximeter.

Measurement of oxygen saturation levels in blood is a vital activity during most medical treatments. A pulse oximeter is a device most commonly used to perform this measurement. It provides convenient, non-invasive and continuous monitoring of oxygen levels in a human body. However, it is often a tedious task to select the appropriate hardware and software components to manufacture a pulse oximeter that gives accurate results. This paper describes a student project, which had the goals to expose the student to this important technique of applying rapid prototyping methods to the design of a state of the art pulse oximeter.