**1. Introduction**

Knowledge about the importance of oral health and oral hygiene practices, attitudes, and behavior among young adults shows the association of insufficient or irregular oral hygiene with the occurrence of gingival/periodontal diseases, caries, and consequently systemic disease occurrence including cardiovascular disease, cancer, diabetes, respiratory infections, adverse pregnancy outcomes, and neurological disorders [1–8].

Periodontal diseases are highly prevalent and can affect up to 90% of the worldwide population [9]. Periodontal disease is an inflammatory disease, followed by pathologic loss of tooth-supporting tissues (periodontal ligament, gingiva, cementum, and alveolar bone).

Dental caries affects approximately 36% of the worldwide population and is still one of the major causes of tooth loss and pain in industrialized countries [10–12]. Dental caries is a multifactorial disease in which the signs of carious demineralization can be seen on the hard dental tissues [13]. It could cause pain, discomfort, and anxiety, if dental caries is untreated, cause the development of infection and tooth loss [14]. This condition may not only affect an individual's ability to eat and speak properly but may also result in lost work and school hours and affect the individual's overall well-being. The crucial role that a healthy oral microbiome plays in preventing caries and promoting oral health is also being increasingly recognized. Caries prevention has traditionally relied on fluoride exposure, diet control, thorough oral hygiene, and antibacterial measures [15].

The most common forms of periodontal diseases in young adults are gingivitis and periodontitis [16]. Gingivitis is characterized by gingival inflammation, swollen and bleeding gums. In the absence of causal therapy, it may progress to periodontal disease, with the appearance of the periodontal pocket, tissue destruction, and bone resorption [17].

Dental caries, in young adults, is associated with bad oral hygiene habits, more gingivitis, higher consumption of sugar, as well as acidic beverages [18].
