Research Article Differentially Expressed Salivary Proteins in Dental Caries Patients Zaid Majeed Khan, 1 Humera Waheed, 2 Zohaib Khurshid , 3 Muhammad Sohail Zafar , 4,5 Syed Faraz Moin , 1 and Mohammad Khursheed Alam 6 1 National Center for Proteomics, University of Karachi, Karachi 75270, Pakistan 2 Dow College of Biotechnology, Dow University of Health Sciences, Karachi 75270, Pakistan 3 Department of Prosthodontics and Dental Implantology, College of Dentistry, King Faisal University, Al Ahsa 31982, Saudi Arabia 4 Department of Restorative Dentistry, College of Dentistry, Taibah University, Al Madinah, Al Munawwarah 41311, Saudi Arabia 5 Department of Dental Materials, Islamic International Dental College, Riphah International University, Islamabad, Pakistan 6 Preventive Dentistry Department, College of Dentistry, Jouf University, Saudi Arabia Correspondence should be addressed to Syed Faraz Moin; faraz.moin@uok.edu.pk and Mohammad Khursheed Alam; mkalam@ju.edu.sa Received 12 February 2021; Revised 2 September 2021; Accepted 22 September 2021; Published 14 October 2021 Academic Editor: Mauricio Budini Copyright © 2021 Zaid Majeed Khan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Dental caries is a multifactorial disease mainly caused by cariogenic bacteria commonly found in the oral cavity. Dental caries may cause demineralization of the tooth, cavitation, hypersensitivity, pulp inflammation, and even tooth loss if left untreated. Saliva secreted in the oral cavity can serve as a tool for identification of biomarkers for early detection of diseases. In the present study, differential expression of salivary proteins from 33 dental caries patients was compared with 10 control subjects. The unstimulated saliva was analyzed by 12% SDS-PAGE and two-dimensional gel electrophoresis. Gelatin and casein zymography was performed to check for protease activity. Also, salivary IgAs from both groups were compared by sandwich ELISA technique. Dental caries patient’s saliva showed decreased caseinolytic and increased gelatinolytic activity probably due to metalloproteases and cathepsins. Mean salivary levels of sIgA were also significantly higher (p <0:018) in dental caries saliva samples. The 2D electrophoresis profile of both the groups showed regions on gel with visually detectable alterations in protein expression. The present study is among the few initial studies in the locality for identification of protein differences in saliva from dental caries patients and has demonstrated a good potential to identify alterations. However, a large population-based analysis is required to validate these findings to be translated as a tool for indicative applications. 1. Introduction Dental caries (tooth decay) is a common oral condition cause by acids produced by bacteria resulting in dissolution of tooth surface. It is a multifactorial and highly prevalent dis- ease that is related to unhealthy lifestyle of a person. There are about 3.5 billion cases related to oral conditions of which about 2.3 billion are those related to permanent teeth while 532 million cases of dental caries related to primary teeth [1, 2]. Tooth decay is caused by a complex interaction of cariogenic bacteria residing in dental biofilm (plaque) that ferment dietary carbohydrates, produce an acidic pH, and result in demineralization and cavitation. If the condition remains untreated, then it spreads to pulp causing pain and finally leads to tooth loss [3, 4]. The key etiological factors include high consumption of sugary food and beverages, poor hygiene, low salivary function, and fluoride deficiency. Factors like social class, geographical location, race, age, and sex are also influential in developing caries [5, 6]. Saliva is secreted mainly from three major and several minor salivary glands. Whole mouth saliva (WMS) consists of water, proteins, peptides, electrolytes, minerals, and Hindawi BioMed Research International Volume 2021, Article ID 5517521, 8 pages https://doi.org/10.1155/2021/5517521