Comparative Evaluation of Antimicrobial Efficacy of Silver, Titanium Dioxide and Zinc Oxide Nanoparticles against Streptococcus mutans

Objective: To determine the antimicrobial efficacy of silver, titanium dioxide and zinc oxide nanoparticles against Streptococcus mutans. Material and Methods: Serial dilution method was employed for preparing 1%, 0.5%, 0.25% concentrations of the three test compounds. ATCC 25175 strain of streptococcus mutans was used to assess the antimicrobial activity of test compounds. Equal quantity of BHI broth was dispensed in test tubes containing sectioned tooth and to this the prepared bacterial inoculum was added. Prepared concentrations of test compounds were added accordingly and incubated for 24hrs at 370C. Then, the sectioned tooth was removed and the adherent bacteria were transferred into saline solution by vortexing. These suspensions were transferred onto sterile blood agar plate to make lawn culture and were further incubated at 370C for 24hrs to determine viable bacterial count. The number of colonies were counted manually from each plate and recorded for further analysis. Decrease in number of colonies represents the effective concentration of the test compound against the inhibition of biofilm formation. Results: A significant difference in the colony forming units among all three concentrations of silver (Ag), titanium dioxide (TiO2) and zinc (ZnO) nanoparticles was noted and the antimicrobial effect of nanoparticles was concentration dependent. Inter group comparison of colony forming units with 1%, 0.5% and 0.25% of the test compound revealed that the colony forming units on the ZnO nanoparticles demonstrated highest value followed by TiO2 and the least were with that of the Ag nano particles. Conclusion: Silver, Zinc oxide and Titanium dioxide showed significant antimicrobial effects and the antimicrobial effect of nanoparticles was concentration dependent.

Indirect Bonding In Lingual Orthodontics - A Review.

This is the era of adult orthodontics as more and more adult patients are willing to get done the orthodontic treatment and with this the demand for invisible bracket system and lingual orthodontics as increased considerable. Bonding of brackets in lingual orthodontics is the major concern owing to the fact of poor visibility leading to faulty bracket positioning, which may result in poor post treatment results. Thus indirect bonding is upcoming trend in lingual orthodontics and this article will review the same in detail.

Age Estimation Based On Chronological Stages of Mandibular Third Molar Development.

Age estimation using forensic methodologies cover both living and dead people. In this regard, teeth are far more beneficial for being among the most indestructible tissues of the body, both in life and after death. Considering that maturity is function of age the objective of our study was to explore the utility of stages of tooth development in estimating the chronological age, which may be considered as a tool in forensic investigations. The inference drawn from the observations of the study results support the fact that the developmental stages of mandibular third molar yields acceptable estimates of chronological age of a suitable individual.