Periodontal diseases are worldwide health problems that negatively affect the lifestyle of many people. The long-term effect of the classical treatments, including the mechanical removal of bacterial plaque, is not effective enough, causing the scientific world to find other alternatives. Polymer–drug systems, which have different forms of presentation, chosen depending on the nature of the disease, the mode of administration, the type of polymer used, etc., have become very promising. Hydrogels, for example (in the form of films, micro-/nanoparticles, implants, inserts, etc.), contain the drug included, encapsulated, or adsorbed on the surface. Biologically active compounds can also be associated directly with the polymer chains by covalent or ionic binding (polymer–drug conjugates). Not just any polymer can be used as a support for drug combination due to the constraints imposed by the fact that the system works inside the body. Biopolymers, especially polysaccharides and their derivatives and to a lesser extent proteins, are preferred for this purpose. This paper aims to review in detail the biopolymer–drug systems that have emerged in the last decade as alternatives to the classical treatment of periodontal disease.

New grafted copolymers possessing structural units of 1-vinyl-3-(1-carboxymethyl) imidazolium betaine were obtained by graft copolymerization of N-vinylimidazole onto gellan gum followed by the polymer-analogous reactions on grafted polymer with the highest grafting percentage using sodium chloroacetate as the betainization agent. The grafted copolymers were prepared using ammonium persulfate/N,N,N′,N′ tetramethylethylenediamine in a nitrogen atmosphere. The grafting reaction conditions were optimized by changing one of the following reaction parameters: initiator concentration, monomer concentration, polymer concentration, reaction time or temperature, while the other parameters remained constant. The highest grafting yield was obtained under the following reaction conditions: c_i = 0.08 mol/L, c_m = 0.8 mol/L, c_p = 8 g/L, t_r = 4 h and T = 50 °C. The kinetics of the graft copolymerization of N-vinylimidazole onto gellan was discussed and a suitable reaction mechanism was proposed. The evidence of the grafting reaction was confirmed through FTIR spectroscopy, X-ray diffraction, ¹H-NMR spectroscopy and scanning electron microscopy. The grafted copolymer with betaine structure was obtained by a nucleophilic substitution reaction where the betainization agent was sodium chloroacetate. Preliminary results prove the ability of the grafted copolymers to bind amphoteric drugs (cefotaxime) and, therefore, the possibility of developing the new sustained drug release systems.

New polymer-bioactive compound systems were obtained by immobilization of triazole derivatives onto grafted copolymers and grafted copolymers carrying betaine units based on gellan and N-vinylimidazole. For preparation of bioactive compound, two new types of heterocyclic thio-derivatives with different substituents were combined in a single molecule to increase the selectivity of the biological action. The 5-aryl-amino-1,3,4 thiadiazole and 5-mercapto-1,2,4-triazole derivatives, each containing 2-mercapto-benzoxazole nucleus, were prepared by an intramolecular cyclization of thiosemicarbazides-1,4 disubstituted in acidic and basic medium. The structures of the new bioactive compounds were confirmed by elemental and spectral analysis (FT-IR and ¹H-NMR). The antimicrobial activity of 1,3,4 thiadiazoles and 1,2,4 triazoles was tested on gram-positive and gram-negative bacteria. The triazole compound was chosen to be immobilized onto polymeric particles by adsorption. The Langmuir, Freundlich, and Dubinin–Radushkevich adsorption isotherm were used to describe the adsorption equilibrium. Also, the pseudo-first and pseudo-second models were used to elucidate the adsorption mechanism of triazole onto grafted copolymer based on N-vinylimidazole and gellan (PG copolymer) and grafted copolymers carrying betaine units (PGB1 copolymer). In vitro release studies have shown that the release mechanism of triazole from PG and PGB1 copolymers is characteristic of an anomalous transport mechanism.

Aim of the Study: This review aims to investigate the pharmacologically induced discoloration of teeth and bones, focusing on how various medications affect the coloration of tooth enamel and dentin. The study seeks to provide insight into the mechanisms behind intrinsic and extrinsic discoloration and their clinical implications. Materials and Methods: A comprehensive literature search was conducted using databases such as PubMed, Google Scholar, and Web of Science. Keywords related to tooth discoloration and medications were used to identify relevant studies, including clinical trials and case reports published between 1990 and 2023. Studies that focused on medication-related discoloration of enamel and bone were analyzed to explore the biochemical interactions between drugs and dental tissues. Results and Discussion: The review identified several classes of medications, including tetracyclines, fluoride, antineoplastic agents, antimalarials, and iron supplements, as primary contributors to both intrinsic and extrinsic tooth discoloration. Tetracycline binds to calcium during tooth formation, leading to permanent discoloration. Fluoride can cause enamel hypomineralization, resulting in fluorosis. Antimalarials and iron supplements cause extrinsic stains due to complex formation with enamel minerals. Treatment options range from professional cleaning and bleaching to more invasive procedures like veneers and crowns, depending on the type and severity of the discoloration. Conclusion: Medication-induced tooth discoloration presents significant clinical challenges due to its varied mechanisms, including intrinsic staining from systemic incorporation of drugs and extrinsic staining from surface agents. Early identification of high-risk medications, preventive measures, and appropriate treatment are essential to minimize aesthetic and psychological impacts. While extrinsic stains are easier to manage, intrinsic discoloration often requires restorative approaches, such as veneers or crowns, for effective resolution.