Abstract The aim of this study was to obtain ionic quantification in periradicular medium after diffusion tests of the solution used inside root canals during the electrochemical dissolution of endodontic file fragments and the NiTi-containing dissolution product via an apical foramen. Thirty single-rooted extracted human teeth had root canals prepared and were attached to Eppendorf tubes filled with sterile saline. The samples were divided into 3 groups (n = 10) according to the solution used inside the root canal during the diffusion tests: Group 1: [NaF 12 g/L + NaCl 1 g/L]; Group 2: [NaF 12 g/L + NaCl 1 g/L + NiTi 0.50 g/L]; Group 3: [NaF 6 g/L + NaCl 0.5 g/L + NiTi 0.25 g/L]. The sample in each Eppendorf tube was then analyzed to assay the ionic quantification in periradicular medium. The groups were compared in relation to ionic quantifications (Kruskal-Wallis and Dunn’s tests, p ≤ 0.05). Group 2 showed significantly higher F-, Ni and Ti quantities than groups 1 and 3 (p < 0.05). Group 3 showed significantly higher Ti and Ni quantities than group 1, where no measurable quantities of Ti and Ni were observed (p < 0.05). The conclusions were that a 50% dilution of the NiTi-containing dissolution product resulted in significantly lower F-, Ni and Ti quantities compared to the undiluted product. The quantifications observed here suggest that irrigation is recommendable during the electrochemical dissolution process to reduce the resultant ion concentrations in both the root canal and the periradicular medium.

Abstract Objective: To evaluate traumatic dental injuries (TDI) in primary teeth and the association of gender and age with different injuries. Material and Methods: Records of patients with TDI in primary teeth were included. The following parameters were registered: gender and age, place of trauma, cause of trauma, affected tissue and tooth, number of injured teeth, type of injury, and gingival and bone damage. A logistic regression analysis was performed to explore the interaction between gender and age on the occurrence of types of injuries (p≤0.05). Results: The total of 721 records were evaluated and 370 records were included, being 61.6% boys and 60.5% children aged 0-3 years old, with 658 primary teeth affected. The support tissue was most affected (496/658), followed by dental tissue (139/658). Enamel/dentine fracture with pulp exposure (n=51) and intrusion (n=131) were the most common injuries of dental and support tissues, respectively. In general, boys suffered more traumas than girls, regardless of the age range. As for concussion, logistic regression confirms that gender and age are also influencers. Girls (OR=1.822, CI = 1.050-3.164, p=0.033) in the 4-6 year age group (OR=2.15, CI = 1.239-3.747, p=0.007) are more likely to have concussions. Children age 4-6 years were less likely to suffer an intrusion (OR=0.496; CI = 0.278-0.886; p=0.018). Conclusion: Gender and age influence concussion and intrusion in the primary teeth.