Background: Allergy is one of the most widespread diseases in this century. Allergy-causing materials used in dentistry are most frequently metals, such as nickel, cobalt, palladium, and amalgam, certain components of dental composites, denture resin materials, and even certain mouthwash components. The aim of this study was to assess dentists’ experience regarding allergies occurring in their practice among patients and among dental team members.Material and methods: We conducted a questionnaire-based study, in which 104 dentists responded.Results: Immediate allergic reactions were more often caused by different drugs, detergents, and anesthetics, while delayed allergic reactions were mostly caused by acrylates. Allergic reactions occurred more often among women than men, but the difference was not statistically significant (p = 0.3).Conclusions: Our results suggest that allergies in dentistry appear mainly among adults, caused mostly by acrylates, metals, and different drugs. Immediate allergic reactions are often present, and mostly women are susceptible to allergies.

Background: The most common dental materials are resin composite direct restorative materials and dentin adhesives, which are marketed with different techniques, application recommendations, and compositions, making it difficult to choose the most suitable material and method for different cases. The present study aimed to investigate mechanical properties of teeth restored with universal and bulk-fill composites, by using different dentin adhesives and techniques, under in vitro conditions. Material and methods: The study was carried out on freshly extracted premolar and molar teeth. After cavity preparation, the teeth were restored with conventional and bulk-fill resin composites, using different adhesive techniques. To assess the effect of the cavity preparation, the direct restoration, and the adhesive protocol on the tooth structure, a transillumination method and Vickers’ microhardness measurements were carried out. Results: The universal composite showed an average hardness of 55.35 HV at the occlusal level of the restoration, while the bulk-fill composite showed an average of 79.93 HV at the same level. A statistically significant difference was found between the hardness values of the two composites (p = 0.02). The transillumination test revealed micro-fissures in the tooth structure in the first phase after cavity preparation and also after polymerization. Conclusions: The bulk-fill composite showed higher hardness values than the universal composite. The tested dentin adhesives did not significantly affect the hardness of the dentin at the level of the adhesive interface. Fissures can appear in any phase of the direct restoration, after cavity preparation and polymerization.