Scanning electron microscopic evaluation of root canal surfaces prepared with three rotary endodontic systems: Lightspeed, ProTaper and EndoWave

Background and Objectives: The purpose of this in vitro study was to  evaluate and compare the cleaning efficiency, preparation time, instrument deformation and fracture with LightSpeed (LS), ProTaper (PT) and  EndoWave (Ew) rotary instruments.Materials and Methods: A total of 45 freshly extracted human mandibular premolars were subjected for the study. They were divided into three groups, each group consisting of 15 teeth. Group 1: The canals were prepared with LS system; Group 2: PT rotary system, Group 3: Ew rotary system. All the groups were prepared according to manufacturerfs recommendation, using 5.25% sodium hypochlorite and 17%  ethylenediaminetetraacetic acid (dent wash, prime dent) alternately as an irrigants. Crowns of each tooth were removed with diamond disks at the level of cemento enamel junction. Canal length was determined by placing a size 10 K.file. The working length was 0.5 mm short of canal length. Two longitudinal grooves were prepared on the lingual and buccal surfaces of each root to facilitate vertical splitting with a chisel after canal  instrumentation. The sections were then observed under scanning electron microscope for presence or absence of debris and smear layer and the photographs were taken at coronal, middle and apical 1/3 with a magnification of ~200 and ~1000 respectively. The time taken to enlarge each canal was recorded in minutes and seconds. The instruments were examined after every use for deformation. The scores recorded were statistically analyzed using one.way analysis of variance and Mann.Whitney test.Results: There was statistically significant difference with regard to removal of debris and smear layer at coronal, middle and apical third for LS versus PT and LS versus Ew (P < 0.01). There was no significant difference  between PT and Ew. The mean preparation time for LS, PT and Ew was 1.76, 2.50 and 2.75 respectively. Interpretation and Conclusion: The study demonstrated that, LS instrumentation removed debris and smear layer effectively with shorter preparation time and Ew instrument showed deformation.Key words: Debris, EndoWave, instrument deformation, LightSpeed, nickel-titanium instruments, preparation time, ProTaper, scanning electron microscope analysis, smear laye

A comparative study of retention of complete denture base with different types of posterior palatal seals – an in vivo study

GS Chandu,1 BS Hema,2 Harsh Mahajan,1 Antriksh Azad,2 Ipsita Sharma,3 Anurag Azad4 1Department of Prosthodontics, Rishiraj College of Dental Sciences and Research Centre, Bhopal, Madhya Pradesh, India; 2Department of Conservative Dentistry, Rishiraj College of Dental Sciences and Research Centre, Bhopal, Madhya Pradesh, India; 3Department of Oral Pathology, RKDF Dental college and Research centre, Bhopal, Madhya Pradesh, India; 4Department of Oral and Maxillofacial Surgery, Bhabha College of Dental Sciences and Research Centre, Bhopal, Madhya Pradesh, India Aim: To evaluate retention of complete denture base with different types of posterior palatal seals. Material and methods: Ten male patients between the age group of 50 years to 60 years were selected for the study. After the primary and secondary impressions were taken, five casts were made including a cast without posterior palatal seal, a cast with single bead posterior palatal seal, a cast with double bead posterior palatal seal, a cast with butterfly shaped posterior palatal seal, and a cast with posterior palatal seal with low fusing compound by functional method. Results: It was observed that retention increased up to 108% in the posterior palatal seal with low fusing compound with functional method and the posterior palatal seal that was obtained by using functional method provided greater retention than a denture base without posterior palatal seal. Conclusion: It was concluded that the incorporation of a posterior palatal seal is important for obtaining optimum retention of the maxillary complete denture. Keywords: posterior palatal seal, denture base, complete denture, functional metho

Self-assembling peptide nanofibers containing phenylalanine for the controlled release of 5-fluorouracil

Narayanan Ashwanikumar,1 Nisha Asok Kumar,2 Padma S Saneesh Babu,2 Krishnankutty C Sivakumar,3 Mithun Varghese Vadakkan,1 Parvathi Nair,1 Ilamathi Hema Saranya,1 Sivakumari Asha Nair,2 Gopalakrishnapillai S Vinod Kumar1 1Chemical Biology, Nano Drug Delivery Systems, Bio-Innovation Center, 2Cancer Research Programme, 3Distributed Information Sub-Centre (Bioinformatics Centre), Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram, Kerala, India Abstract: The study shows that RADA-F6 peptide with pH-responsive self-assembling nature can be effectively used as a drug delivery system for the sustained release of a potent anticancer drug 5-fluorouracil (5-FU) at basic pH. As 5-FU contains the aromatic pyrimidine ring, RADA-F6 system is suitable for entrapping an aromatic drug due to effective π–π stacking with phenylalanine and be able to show better controlled release behavior. The stability and controlled release nature of RADA-F6 in different conditions followed by 5-FU entrapment at in silico conditions was confirmed by molecular dynamics simulation taking RADA-16 as control. Cytotoxicity of the drug-loaded RADA-F6 was measured by MTT assay and cellular uptake by confocal microscopy. Physicochemical characterization and further Western blot analysis and flow cytometric studies confirm that RADA-F6 can be successfully used as an efficient vector for pH-sensitive, controlled 5-FU delivery system. Keywords: scaffold, drug delivery, nanofibrous, aromati