Óleos essenciais do gênero Citrus como alternativa aos solventes endodônticos convencionais: importância no cenário pandêmco da COVID-19

Abstract

Endodontic failures are frequent even with the technical advances in the field, and retreatment is indicated then. Removing the filling material from the root canal is an important step for the clinical success of retreatment, but it requires chemical solvents that are often harmful to health and the environment. Therefore, this study aimed to assess the efficacy and safety of essential oils belonging to the Citrus genus as an alternative to conventional endodontic solvents. It investigated the solvent capacity and the biological activity of ten essential oils (1 - C. aurantium var. amara; 2 - C. Comida, 3 - C. Comida, 4 - C. sinensis; 5 - C. grandis; 6 - C. medica limonum; 7 - C. aurantium dulcis; 8 - C. reticulata; 9 - C. sinensis; 10 - C. sinensis) and three controls (eucalyptol, Endossolv®E, and chloroform). Gas chromatography/mass spectrometry gave the chemical profile of the essential oils, disintegration tests assessed the oils' effectivity on gutta-percha removal, and scanning electron microscopy evaluated the durability by penetration and the gutta-percha's surface. Moreover, the biological assessments included: a) antimicrobial analysis through the turbidimetric analysis against E. faecalis (ATCC 51299) and C.albicans (ATCC 10231); b) antioxidant activity using the method of sequestration of reactive oxygen species; c) cell toxicity on L929 fibroblasts through 3-(4,5-dimethyl-2thiazolyl)-2,5-diphenyl-2H tetrazolium (MTT) assay. D-limoneo and βmyrcene were the two joint components found in all essential oils. Oil 7 was more effective in removing gutta-percha. All oils were bacteriostatic against E. faecalis (ATCC 51299), and only oils 1, 5, and 6 showed antifungal activity against C. albicans (ATCC 10231). Compared to control, oils 1-4, 6, 7, and 9 showed higher antioxidant activity. None of the oils were toxic against L929 cells up to 62.5 µg/mL. We concluded that oil 7 is a viable alternative to organic solvents since it presented chemical compounds with solubilization capacity, exhibited antimicrobial and antioxidant activities, and showed low cytotoxicity. Furthermore, this oil represents a natural option and offers welfare to patients seeking practical solutions but also looking for alternatives with less social, environmental, and economic impacts.