Review Article International Journal of Dental Materials 2019; 1(2) Advances in alginate impression materials: a review Sahithi Alaghari 1,* , Surekha Velagala 1 , Rama Krishna Alla 2 , Ramaraju AV 3 1 Undergraduate student, Vishnu Dental College, Bhimavaram, West Godavari, 534202, Andhra Pradesh, India. 2 Assistant Professor, Department of Dental Materials, Vishnu Dental College, Bimavaram, West Godavari, 534202, Andhra Pradesh, India. 3 Professor, Department of Prosthodontics, Vishnu Dental College, Bhimavaram, West Godavari, 534202, Andhra Pradesh, India. INFORMATION Article History Received 26 September 2019 Accepted 11 October 2019 Available online 15 November 2019 _______________________________ KEYWORDS Alginate Dust-free alginates Chromatic alginate Self-disinfectant alginates Tray adhesives Nanoparticles ABSTRACT Alginate is an irreversible elastic hydrocolloid which has various applica- tions in dentistry. The applications of alginates include making impres- sions of edentulous and partially edentulous arches, duplication of casts, and for making study models. Alginates possesses numerous vital proper- ties such as hydrophilicity, ability to record finer details, elastic recovery and inexpensive; makes this material widely used in dentistry. Though algi- nate is the most commonly used impression material, it has some inherent disadvantages. Alginates contain low-density fine filler particles, which may arise in the form of dust and inhalation these dust particles may cause respiratory problems. Further, they are highly dimensionally unstable due to syneresis & imbibition. Besides, alginates do not adhere to non - perforated trays, low viscosity resulting in gag reflex in some patients, and the inability to identify the correct consistency to load. Several modifica- tions were made in the composition of conventional alginates to address their shortcomings. This article reviewed various recent advances in the alginate impression materials and their performance. Correspondence: *Corresponding author Email Address: sahithi.alaghari@gmail.com How to cite this article: Alaghari S, Velagala S, Alla RK, Ramaraju AV. Advances in alginate impression materi- als: a review. Int J Dent Mater 2019;1(2): 55-59. DOI: http://dx.doi.org/10.37983/IJDM.2019.1203 1. Introduction Alginate is an elastic and irreversible hydrocolloid impression material, which has been using in dentistry for many years. Alginate impression mate- rials is essentially an alginic acid, which is obtained from brown seaweed (marine plant). Alginate is a high molecular weight linear polymer of anyhy- dro-D-mannuronic acid [1]. Alginate is a linear acidic polysaccharide comprising β-d-mannuronate (M) and its C-5 epimer α-l-guluronate (G). In alginate polymers, the residues are arranged in a block structure of a ho- mopolymer (polymannuronate (PM) or polyguluronate (PG)) or heteropoly- mer (a mixed sequence of these residues). The properties of alginate depend on the degree of polymerization and the ratio of mannuronan (M) and Gulu- ronan blocks (G). As shown in figure 1, the mannuronan chains are stretched