Resulting in a high economic and biological cost, the traditional therapeutic approach to carious lesion management is still largely restorative. Minimally invasive (MI) treatment offers an attractive alternative to managing carious lesions in a more conservative and effective manner, resulting in enhanced preservation of tooth structure. The aim of this review was to summarize the evidence behind several MI alternatives for carious lesion management, including the use of sealants, infiltration, atraumatic restorative treatment (ART), and selective carious tissue removal (e.g., indirect pulp capping, stepwise removal, or selective removal to soft dentine). Relevant literature was screened, and articles reporting randomized controlled trials or systematic reviews of strategies to manage non-cavitated or cavitated carious lesions in adults and children were included. Fifty six articles met the inclusion criteria. For non-cavitated lesions, the use of sealants is supported by strong evidence, while the evidence for infiltration of proximal lesions is moderate. For deep cavitated lesions, selective removal to soft dentin and/or stepwise excavation is supported by strong evidence. The use of the ART technique to restore cavitated lesions is also supported by strong evidence as a suitable strategy that has been used extensively in the literature concerning non-dental settings. Preservation of tooth structure through the use of MI treatment for both non-cavitated and cavitated lesions is supported by moderatestrong evidence, which supports the paradigm shift towards routine use of more conservative strategies in the treatment of carious lesions.

The oral cavity is inhabited by a wide spectrum of microbial species, and their colonization is mostly based on commensalism. These microbes are part of the normal oral flora, but there are also opportunistic species that can cause oral and systemic diseases. Although there is a strong exposure to various microorganisms, the oral mucosa reduces the colonization of microorganisms with high rotation and secretion of various types of cytokines and antimicrobial proteins such as defensins. In some circumstances, the imbalance between normal oral flora and pathogenic flora may lead to a change in the ratio of commensalism to parasitism. Healthy oral mucosa has many important functions. Thanks to its integrity, it is impermeable to most microorganisms and constitutes a mechanical barrier against their penetration into tissues. Our study aims to present the role and composition of the oral cavity microbiota as well as defense mechanisms within the oral mucosa which allow for maintaining a balance between such numerous species of microorganisms. We highlight the specific aspects of the oral mucosa protecting barrier and discuss up-to-date information on the immune cell system that ensures microbiota balance. This study presents the latest data on specific tissue stimuli in the regulation of the immune system with particular emphasis on the resistance of the gingival barrier. Despite advances in understanding the mechanisms regulating the balance on the microorganism/host axis, more research is still needed on how the combination of these diverse signals is involved in the regulation of immunity at the oral mucosa barrier.

Objective. The aim of the study was to compare under in vitro conditions marginal sealing of 4 different bulk‐fill materials composite restorations of class II. Methods. Comparative evaluation concerned 4 composites of a bulk‐fill type: SonicFill, Tetric EvoCeram Bulk Fill, Filtek Bulk Fill, and SDR. The study used 30 third molars without caries. In each tooth 4 cavities of class II were prepared. The prepared tooth samples were placed in a 1% methylene blue solution for 24 h, and after that in each restoration the depth of dye penetration along the side walls was evaluated. Results. The highest rating (score 0, no dye penetration) was achieved by 93.33% of the restorations made of the SDR material, 90% of restorations of SonicFill system, 86.66% of restorations of the composite Filtek Bulk Fill, and 73.33% of restorations of the Tetric EvoCeram Bulk Fill. Conclusion. The performed study showed that bulk‐fill flowable or sonic‐activated flowable composite restorations have better marginal sealing (lack of discoloration) in comparison with bulk‐fill paste‐like composite.

Chitosan is one of the emerging materials for various applications. The most intensive studies have focused on its use as a biomaterial and for biomedical, cosmetic, and packaging systems. The research on biodegradable food packaging systems over conventional non-biodegradable packaging systems has gained much importance in the last decade. The deacetylation of chitin, a polysaccharide mainly obtained from crustaceans and shrimp shells, yields chitosan. The deacetylation process of chitin leads to the generation of primary amino groups. The functional activity of chitosan is generally owed to this amino group, which imparts inherent antioxidant and antimicrobial activity to the chitosan. Further, since chitosan is a naturally derived polymer, it is biodegradable and safe for human consumption. Food-focused researchers are exploiting the properties of chitosan to develop biodegradable food packaging systems. However, the properties of packaging systems using chitosan can be improved by adding different additives or blending chitosan with other polymers. In this review, we report on the different properties of chitosan that make it suitable for food packaging applications, various methods to develop chitosan-based packaging films, and finally, the applications of chitosan in developing multifunctional food packaging materials. Here we present a short overview of the chitosan-based nanocomposites, beginning with principal properties, selected preparation techniques, and finally, selected current research.

Good oral hygiene is an important factor in oral and general health, especially in orthodontic patients, because fixed appliances might impede effective oral hygiene and thus increase the risks of tooth decay, periodontal disease and general health complications. This study investigated the impact of fixed orthodontic appliances on the distribution of dental biofilm in teenagers. Supragingival plaque was assessed at T0, T1 and T2. The distribution of the biofilm was analyzed. Approximal Plaque Index (API) and Bonded Bracket Index (BBI) were used to measure the presence of dental plaque. After insertion of the fixed appliance, the dental plaque indices values in the orthodontically treated group were significantly higher (p < 0.05) than in the control group. Fixed orthodontic appliances caused significant changes in the distribution of the biofilm. This was characterized by the change of location of the dental plaque. In the orthodontic group, we observed an increase in the amount of the supragingival plaque on the vestibular surface of the teeth.

Porosity is an important parameter for characterizing the microstructure of solids that corresponds to the volume of the void space, which may contain fluid or air, over the total volume of the material. Many materials of natural and technically manufactured origin have a large number of voids in their internal structure, relatively small in size, compared to the characteristic dimensions of the body itself. Thus, porosity is an important feature of industrial materials, but also of biological ones. The porous structure affects a number of material properties, such as sorption capacity, as well as mechanical, thermal, and electrical properties. Porosity of materials is an important factor in research on biomaterials. The most popular materials used to rebuild damaged tooth tissues are composites and ceramics, whilst titanium alloys are used in the production of implants that replace the tooth root. Research indicates that the most comprehensive approach to examining such materials should involve an analysis using several complementary methods covering the widest possible range of pore sizes. In addition to the constantly observed increase in the resolution capabilities of devices, the development of computational models and algorithms improving the quality of the measurement signal remains a big challenge.