Comparative analysis of antigen-presenting cells in gingival tissues in healthy and periodontitis patients.

AIMS: Microbial flora of dental plaque trigger innate and adaptive immune responses. The function of antigen-presenting cells (APCs) is to bridge the innate and adaptive immune systems. The human immune system contains three main types of APCs: dendritic cells (DC) (Langerhans cells (LCs) and interstitial DCs, IDCs), macrophages and B lymphocytes. In this study, the distribution and density of all APCs in healthy and inflamed human gingival tissue were comparatively analysed. METHODS: Research was conducted on gingival biopsy specimens obtained from 55 patients and classified in three groups: healthy gingiva (control group, n=10), moderate periodontal disease (PD) (n=21) and severe PD (n=24). For APCs' identification antibodies raised against CD1a (for LCs), S100 protein (for iDCs), CD68 (for macrophages) and CD20 (for B lymphocytes) were used. RESULTS: Increased density of IDCs, macrophages and B lymphocytes in lamina propria and reduced density of LCs in the gingival epithelium were found in patients with periodontitis. Simultaneously, it was noticed an increased concentration of macrophages and B cells in the gingival epithelium in patients with PD. No statistically significant difference in the distribution and density of APC was found among patients with moderate and advanced periodontitis. CONCLUSIONS: It was hypothesised that in the periodontitis the role of antigen presentation was largely taken from LCs by the DCs, macrophages and B cells. These APCs are thought to have less protective and tolerogenic potential than LCs and this is a significant reason for alveolar bone destruction in periodontitis.

Effect of augmented reality simulation on administration of local anaesthesia in paediatric patients.

BACKGROUND: Augmented reality (AR) is a simulation of a three-dimensional environment created using hardware and software that provides the user with realistic experiences and ability to interact. The aim of the study was to evaluate the impact of AR simulator on the perception of learning and acute stress level in students administering local anaesthesia to paediatric patients relative to standard teaching methods. MATERIAL AND METHODS: The prospective study included 21 fourth- and fifth-year students enrolled in 5-year dental programme. In addition to conventional training, the students of the study group used the augmented reality simulator in a dental office 2 hours weekly in 2 weeks. The level of salivary cortisol was measured before and after the anaesthetic procedure as one of the indicators of acute stress. RESULTS: A statistically significant shorter time to perform infiltrative anaesthesia technique for the anterior superior alveolar nerve was observed in students using the AR technique (28.91 ± 9.06 seconds in the study group and 39.80 ± 9.29 seconds in the control group). The level of cortisol before and after anaesthesia was statistically significant in all subjects (cortisol concentration was 0.53 µg/dL before anaesthesia and 2.44 µg/dL after the procedure); however, there was no statistically significant difference between the groups. CONCLUSION: The AR concept may influence better manipulation and control of the syringe in students administering their first anaesthetic injection to paediatric patients, but may not reduce acute stress.