# Dental Hydrogels with Essential Oils with Potential Activity in Periodontitis
## 1 Introduction  
In human dentistry, the use of herbal extracts and essential oils as plaque-fighting and tooth-cleaning agents has traditionally been successful. These phytochemicals also provide a potential strategy in the prevention and treatment of dental caries, oral inflammation, and other oral infections [1] and could be a potent antibiotic substitute. Essential oils are complex mixtures of many compounds, primarily produced from aromatic and medicinal plants, including terpenoids, aromatic components derived from phenol, and aliphatic components. From a chemical standpoint, their contents can change as a result of climate change, depending on the organ portion of the plant, age, species, and subspecies, and changes may occur as a result of the oil extraction mechanism [2]. As a result, their contents are unique to each of them. Certain essential oils have antimicrobial and antioxidant properties, and in combination with other substances, they can have bacteriostatic, bactericidal, and anti-inflammatory effects, so they are increasingly used in the treatment of certain conditions with a certain spectrum, especially since they are simple to include into hydrogel formulations, this opens up new possibilities for the administration of active chemicals at the level of mucosal membranes, particularly antibacterial, antioxidant, and anti-inflammatory drugs, which are all experiencing rapid growth [3]. According to the existing studies in the literature, there is still utility to using essential oils by incorporating and preserving the antimicrobial effect of the active constituents, these being integrated into wound dressings with the aim of preventing, limiting, or treating other infections that tend to occur at the level of wounds and at the same time they can facilitate the regeneration of soft tissues. These recent studies highlight the fact that more and more natural constituents extracted from plants can control the stages of healing [4]. The idea of various systems, which is anticipated to be in favor of the release of active substances as well as the avoidance of side effects and the reduction in dosing intervals, is the foundation of the current studies on drug delivery systems. Particularly, contemporary mucosal delivery systems for antibiotics, antioxidants, and anti-inflammatory drugs have improved in this area with regard to the avoidance of adverse effects, simple administration methods, and a tolerable concentration of the active ingredients in the mucosa [5]. In medicine and pharmacy, hydrogels are becoming increasingly important. They appear to be one of the most encouraging classes of biomaterials because of their favorable physicochemical characteristics, biocompatibility, and designed activity with living environments [6]. One of the most researched topics at the intersection of engineering and medicine is the development of hydrogels for biological applications [7]. Hydrogels have been created for and employed in a variety of medical practices due to their high-water content, chains of hydrophilic polymers, and strong biocompatibility [8]. Since the characteristics of hydrogels can be altered through various chemical studies, their rational design and engineering enabled new methods for the release of small molecules, proteins, and cells. Additionally, they served as tissue scaffolds for the management of cell lines, stem cell development, and tissue regeneration [7]. These are frequently enhanced with natural ingredients that set them apart and place them on a higher scale than traditional medications. Dentistry is one of the domains of medicine where the most common pathologies have a bacterial and fungal origin. The most prevalent diseases, such as dental caries, periodontal disease, and endodontic lesions, appear because of well-known bacterial and fungal pathogens: _Streptococcus mutans_, _Streptococcus salivirus_, _Streptococcus salgiumis_, _Porfromomas giganis_, _Prerotella internedia_, _Actinobacillus actinoyeteremomitans_, _Candidas facialibica_, etc. [9].