Development of Lipidic Nanoplatform for Intra-Oral Delivery of Chlorhexidine: Characterization, Biocompatibility, and Assessment of Depth of Penetration in Extracted Human Teeth.

Microorganisms are the major cause for the failure of root canal treatment, due to the penetration ability within the root anatomy. However, irrigation regimens have at times failed due to the biofilm mode of bacterial growth. Liposomes are vesicular structures of the phospholipids which might help in better penetration efficiency into dentinal tubules and in increasing the antibacterial efficacy. Methods: In the present work, chlorhexidine liposomes were formulated. Liposomal chlorhexidine was characterized by size, zeta potential, and cryo-electron microscope (Cryo-EM). Twenty-one single-rooted premolars were extracted and irrigated with liposomal chlorhexidine and 2% chlorhexidine solution to evaluate the depth of penetration. In vitro cytotoxicity study was performed for liposomal chlorhexidine on the L929 mouse fibroblast cell line. Results: The average particle size of liposomes ranged from 48 ± 4.52 nm to 223 ± 3.63 nm with a polydispersity index value of <0.4. Cryo-EM microscopic images showed spherical vesicular structures. Depth of penetration of liposomal chlorhexidine was higher in the coronal, middle, and apical thirds of roots compared with plain chlorhexidine in human extracted teeth when observed under the confocal laser scanning microscope. The pure drug exhibited a cytotoxic concentration at which 50% of the cells are dead after a drug exposure (IC50) value of 12.32 ± 3.65 µg/mL and 29.04 ± 2.14 µg/mL (on L929 and 3T3 cells, respectively) and liposomal chlorhexidine exhibited an IC50 value of 37.9 ± 1.05 µg/mL and 85.24 ± 3.22 µg/mL (on L929 and 3T3 cells, respectively). Discussion: Antimicrobial analysis showed a decrease in colony counts of bacteria when treated with liposomal chlorhexidine compared with 2% chlorhexidine solution. Nano-liposomal novel chlorhexidine was less cytotoxic when treated on mouse fibroblast L929 cells and more effective as an antimicrobial agent along with higher penetration ability.

Publication analysis in Bay for Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation Nations.

Background: Research output provides an insight into the development of the scientific capability of a country. Budget allocation for research and development (R&D) is directly proportional to the research output of a country. While developed countries spend a significant percentage of their GDP on R&D, developing countries do not have enough resources to invest in R&D. Countries in the Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) Nations has received significantly less attention from outside the region in studying R&D and research publication scenario of the region. The research output of BIMSTEC countries was analyzed using various metrics in this paper. Methods: Data on citation per paper, Field Weight Citation Impact (FWCI), paper per researcher, collaborative publications, and output in top 10 percent journals was extracted from one of the largest abstract and citation database of peer-reviewed literature, Scopus and its affiliate SciVal, for a period of 6 years between 2012-2017. Percentage of R&D spend, researchers per million population, and total scientific output were extracted from World Bank data. Results: India and Thailand have a higher quantum of publications compared to other countries. Subjects like clinical, technology, Computer Science have a larger publication number as compared to other subject areas like Social Science, Arts, Education, Law, and Physiology. The researcher population and research spend of a nation have an evident implication on the publication though no direct relation can be derived. Conclusion: Huge disparities in terms of percentage of research spent, research output, papers per researcher, and output with national and international authorship differ for countries. Higher research spent and publication count are not positively correlated with better FWCI.

Etiology and classification of food impaction around implants and implant-retained prosthesis.

BACKGROUND: Food impaction is a common risk factor for the initiation of peri-implant inflammation and failure of the osseointegrated implant. Although clinicians do acknowledge the presence of food impaction around implants and implant-retained prosthesis, no classification system has yet classified the food impaction around the implant and implant-retained prosthesis. PURPOSE: The present paper aims to identify and classify the plausible etiology of food impaction around implants and implant-related prosthesis. MATERIALS AND METHODS: The following search terms were utilized for data search: "Food Impaction" AND "Implants" AND "Food Impaction" AND "Perimplantitis" AND "Food Impaction" AND "Classification." Articles that were written in the English language in PubMed and Cochrane Library database from 1930 till September 2018 were scrutinized. A total of 24 articles were scrutinized, out of which only 15 articles were selected. RESULTS: Food impaction around implants is broadly classified into five categories based on the number of implants, nature of implants prosthesis involved for replacement and relation of the implant prosthesis to the adjacent tooth, restoration, or prosthesis. CONCLUSION: This is the first classification designed to classify food impaction around dental implants and implant-retained prosthesis. The classification can be used by clinicians for optimal diagnosis, interpretation, and treatment plan for patients.

Effects of nonaldehyde immersion disinfection on the mechanical properties of flexible denture materials.

STATEMENT OF PROBLEM: Variation in the baseline mechanical properties of polyamide thermoplastic polymers used in the fabrication of prosthetic dental appliances and the effects of nonaldehyde disinfectants on the mechanical properties of these polymers are unclear. PURPOSE: The purpose of this in vitro study was to compare the flexural and impact strengths of 2 flexible denture materials (Valplast and Sunflex) and evaluate the effect of 24-hour immersion in nonaldehyde disinfectant (Perform) on their flexural and impact strengths. MATERIAL AND METHODS: Of 48 specimens of Valplast and Sunflex, half were immersed in nonaldehyde disinfectant solution containing the active ingredient 2% peroxymonosulfate for 24 hours. Flexural and impact strengths were measured using a universal testing machine. The Student t test with Bonferroni correction was used (α=.008). RESULTS: For the Valplast group, the mean ±standard deviation flexural strength was 27.8 ±0.57 MPa, and the impact strength was 3.5 ±0.98 kJ/m2. For the Sunflex group, the mean flexural strength was 57.4 ±4.09 MPa, and the impact strength was 6.0 ±3.11 kJ/m2. Sunflex showed greater flexural strength (P≤.001) and impact strength (P=.001) than Valplast. A significant increase in the impact strength (P≤.001) but not in the flexural strength of Valplast was observed after exposure to the disinfectant solution. Immersion disinfection had no significant effect on the strength of Sunflex. CONCLUSIONS: The flexural and impact strengths of Sunflex were significantly greater than those of Valplast. Immersion disinfection with peroxymonosulfate had no significant effect on Sunflex but increased the impact strength of Valplast.

Is zirconia a viable alternative to titanium for oral implant? A critical review.

PURPOSE: Titanium based implant systems, though considered as the gold standard for rehabilitation of edentulous spaces, have been criticized for many inherent flaws. The onset of hypersensitivity reactions, biocompatibility issues, and an unaesthetic gray hue have raised demands for more aesthetic and tissue compatible material for implant fabrication. Zirconia is emerging as a promising alternative to conventional Titanium based implant systems for oral rehabilitation with superior biological, aesthetics, mechanical and optical properties. This review aims to critically analyze and review the credibility of Zirconia implants as an alternative to Titanium for prosthetic rehabilitation. STUDY SELECTION: The literature search for articles written in the English language in PubMed and Cochrane Library database from 1990 till December 2016. The following search terms were utilized for data search: "zirconia implants" NOT "abutment", "zirconia implants" AND "titanium implants" AND "osseointegration", "zirconia implants" AND compatibility. RESULTS: The number of potential relevant articles selected were 47. All the human in vivo clinical, in vitro, animals' studies were included and discussed under the following subheadings: Chemical composition, structure and phases; Physical and mechanical properties; Aesthetic and optical properties; Osseointegration and biocompatibility; Surface modifications; Peri-implant tissue compatibility, inflammation and soft tissue healing, and long-term prognosis. CONCLUSIONS: Zirconia implants are a promising alternative to titanium with a superior soft-tissue response, biocompatibility, and aesthetics with comparable osseointegration. However, further long-term longitudinal and comparative clinical trials are required to validate zirconia as a viable alternative to the titanium implant.