Structural Effects of Various Commonly used Disinfectant Solutions on Gutta-Percha: An Atomic Force Microscopic Study

Introduction: Gutta-percha cones can be contaminated by various ways. Literature revealed several methods for rapid decontamination of gutta-percha cones in dentistry. Atomic force microscope (AFM) is a well-established methodology for structural characterization of materials. Aim: The purpose of the study is to evaluate the effects of 5% sodium hypochlorite 2% chlorhexidine, 2.2% glutaraldehyde, 6% hydrogen peroxide on the surface structure of standardizedgutta-percha cones in their respective cold sterilization times 1, 10, 15, 10 minutes respectively as found in many studies. Materials and methods: Forty standardized gutta-percha cones (ISO standardized size 60) were cut 3 mm from the tip, attached to a glass base and immersed in 5% sodium hypochlorite, 2% chlorhexidine, 2.2% glutaraldehyde, 6% hydrogen peroxide for 1, 10, 15, 10 minutes. After this, the samples were positioned in the atomic force microscope. Theanalyses were performed between 1 and 2 mm from the tip after each period of immersion in NaOCl. Gutta-percha cone without any NaOCl treatment were used as control. Root mean square (RMS) parameters for contact mode imaging variations were measured. Results: The differences between RMS values were testedby ANOVA with Fisher’s protected LSD test for multiple comparisons (p < 0.05). Aggressive deteriorative effects on gutta-percha cone elasticity were observed for 5.25% NaOCl at 1 minute when compared to the control (p < 0.05). In addition, 2% chlorhexidine has caused topographic changes after 15 minutes when compared to the control (p < 0.05). Conversely, 2.2% glutaraldehyde, 6% hydrogen peroxide solution did cause minimal alteration on topography or elasticity of gutta-percha cone structure when compared to the control (p > 0.05). Conclusion: Six percent hydrogen peroxide and 2.2% glutaraldehyde are safe alternative for chair side decontamination of gutta-percha cones when compared to 5.25% NaOCl and 2% chlorhexidine.&nbsp

Effect of feeding processed sweet sorghum (Sorghum bicolour (L) moench) crushed residue based complete ration on growth performance and feeding behavior of murrah buffalo calves

Aim: The objective of the present study is to know the effect of feeding processed sweet sorghum (Sorghum bicolour (L) moench) crushed residue (SSCR) based complete ration on growth, feeding behavior and cost of gain in Murrah buffalo calves in order to compare the feeding value of SSCR with sorghum straw (SS) and also find out the efficient way of utilization of SSCR in the diets of growing buffalo calves. Materials and Methods: Experimental complete rations were formulated with SSCR and concentrate in 50:50 ratio and processed in to SSCR chopped and concentrate (SSCRC), mash (SSCRM) and expander extruder pellets (SSCRP). The control ration was SS based complete feed processed in to mash (SSM). 24 Murrah buffalo calves (Average 137 kg body weight and aged 1 year 2 months) were randomly distributed into 4 experimental groups of 6 animals each in a completely randomized design and the experimental rations were offered to 4 groups randomly for a period of 150 days. A 7 day digestion trial was conducted at the end of 150 day growth trial to find out the nutrient digestibility of experimental rations. Eating and ruminating activities were noted every 5 minutes, and each activity was assumed to persist for the entire 5 minutes. Sorting behavior in the calves was observed physically at the time of feeding. The cost of the rations was calculated on the basis of processing cost and the prevailing market prices of the feed ingredients. Results: The DM intake (g/d), digestibilities of DM, organic matter, crude protein and nitrogen free extract and nitrogen (N) balance were higher (P<0.05) in buffalo calves fed SSCRP ration but, comparable among SSCRC, SSCRM and SSM rations. Higher (P<0.01) average daily gain (g), lower feed conversion ratio (FCR) was observed in calves fed SSCRP ration, while comparable among SSCRC, SSCRM and SSM rations. Eating, rumination and total chewing time (minutes/d,minutes/kg DMI and minutes/kg NDFI) and number of chews for eating, rumination and total chewing (per d, per kg DMI and per kg NDFI) were higher (P<0.01) in calves fed SSCRC ration and lower (P<0.01) in SSCRP ration and comparable among SSCRM and SSM rations. Sorting and selection of ration against large fibrous particles in favour of concentrate portion of the ration was observed in SSCRC ration and was not observed in SSCRP, SSCRM and SSM rations. lower (P<0.05) cost (INR) per kg gain was observed in buffalo calves fed SSCRP ration than those fed SSCRC, SSCRM and SSM rations. Conclusion: The present study indicated that SSCR may be used as roughage source in place of SS in complete feeds for economic feeding of buffalo calves. Further, expander-extruder processing of the complete ration improved feed intake, growth rate, feed efficiency and decreased sorting behavior and cost of feeding compared to mash and chopped forms of the ration. [Vet World 2013; 6(3.000): 151-155