A Comparative Evaluation of Intraradicular Smear Removal Efficacy of 2% Chitosan (Low Molecular Weight), 4% Chitosan Citrate, and 10% Citric Acid when Used as Final Rinse in Irrigation Protocols: A Field Emission Scanning Electron Microscopic Study.

AIM: This study aims to compare the smear layer removal efficacy of 2% chitosan (low molecular weight) (C-LMV), 4% chitosan citrate (CC), and 10% citric acid (CA) when used in specific irrigant protocols. MATERIALS AND METHODS: A total of 60 single-rooted maxillary incisors and canines were decoronated, standardized to a root length of 15 mm, and prepared with rotary files up to protaper F3 size. Sodium hypochlorite was used as initial rinse [8 ml]. The samples were divided into experimental (Group III, IV, V, and VI) (n = 10) and control groups (I - 17% EDTA, II - normal saline) (n = 5) based on the type of final rinse solution (5 ml) used, that is, 2% C-LMV, 4% C-citrate, 10% CA, and 1% acetic acid. Samples were dehydrated, split buccolingually, gold sputter coated, and examined in field emission scanning electron microscope. RESULTS: Overall, the Group IV, V, and III presented the least amounts of smear, debris, and erosion among the experimental groups at the apical, middle, and coronal one-thirds of the root canal with a mean value of 1.53 ± 0.42, 1.33 ± 0.42, and 1.60 ± 0.46, respectively, and there was no statistically significant difference (P > 0.05). CONCLUSION: The use of CC as final rinse solution during biomechanical preparation seems promising.

In vitro comparative evaluation of mechanical properties of temporary restorative materials used in fixed partial denture.

INTRODUCTION: Materials used to fabricate provisional restorations can be classified as acrylics or resin composites. Provisional crows can be either prefabricated or custom made. ACRYLICS: These materials have been used to fabricate provisional restorations since the 1930s and usually available as powder and liquid. They are the most commonly used materials today for both single-unit and multiple-unit restorations. In general, their popularity is due to their low cost, acceptable esthetics, and versatility. COMPOSITES: Composite provisional materials use bis-acryl resin, a hydrophobic material that is similar to bis-GMA. Composites are available as auto-polymerized, dualpolymerized and visible light polymerized. PREFORMED CROWNS: Preformed provisional crowns or matrices usually consist of tooth-shaped shells of plastic, cellulose acetate or metal. They are commercially available in various tooth sizes and are usually selected for a particular tooth anatomy. They are commonly relined with acrylic resin to provide a more custom fit before cementation, but the plastic and metal crown shells can also be cemented directly onto prepared teeth. AIMS AND OBJECTIVES: The aim of this study is to choose a material to serve as a better interim prosthesis and to compare three different properties - flexural strength, compressive strength, and color stability. MATERIALS AND METHODS: The samples were made with three different provisional materials (Revotek LC, Protemp 4, TemSpan). RESULT: It was inferred from the study that no one material was superior in all three tested parameters.