Abstract
            Background. Desquamative gingivitis is an immunological chronic disease that is considered  precancerous and has the potential to develop into squamous cell carcinoma. Carcinoembryonic  antigen (CEA), a common tumor marker, increases in many cancers. The present study compared  salivary CEA levels in desquamative gingivitis before and after topical corticosteroid therapy.  
  Methods. This case‒control study was conducted in the Department of Oral and Maxillofacial  Medicine, Tabriz Faculty of Dentistry. Twenty patients with desquamative gingivitis in oral  lichen planus (OLP) background were selected as the case group, with 20 healthy individuals  as the control group. Desquamative gingivitis lesions were confirmed with biopsies. Salivary  samples were obtained from both groups. Second, salivary samples were collected from the case  group after a course of topical corticosteroid therapy. Salivary CEA levels were measured by a  monobind kit using the ELISA method. Independent and paired t-tests were used to analyze the  data in SPSS 17. P<0.05 was considered statistically significant.  
  Results. Before treatment, CEA levels were significantly higher in the case group (174.06±95.55)  than in the control group (55.66±41.26 ng/mL) (P<0.001). Salivary CEA levels in the case group  decreased significantly after the treatment (96.77±66.25 ng/mL) compared to before treatment  (174.06±95.55 ng/mL) (P<0.001).  
  Conclusion. This study demonstrated that CEA levels significantly decreased in patients  with desquamative gingivitis associated with oral lichenoid reaction after receiving topical  corticosteroid therapy.