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BACKGROUND/AIM: Mouthguards are used to prevent dental trauma and orofacial injuries. The aim of this study was to evaluate the influence of ethylene-vinyl acetate (EVA) aging by thermocycling on elastic modulus, stress, strain and shock absorption ability of different ethylene-vinyl acetate brands used for mouthguards. METHODS: Thirty EVA samples with a dimension of 70 × 10 × 3 mm were obtained from four commercial brands (Bioart®, Erkodent®, Polyshok® and Proform®). Fifteen samples were submitted to 10,000 cycles (5°C-55°C) in a thermocycling machine with an immersion time of 30 s and a transfer time of 5 s. The samples were submitted to a uniaxial tensile test in a universal testing machine to calculate the elastic modulus. Data were statistically evaluated by two-way ANOVA and Holm-Sidak test. A three-dimensional model of the anterior maxilla was created using Rhinoceros 5.0. A 3 mm custom-fitted mouthguard was simulated. The three-dimensional volumetric mesh was generated using the Patran software (MSC Software) with isoparametrics, 4-noded tetrahedral elements and exported to Marc/Mentat (MSC Software) as element number 134. A non-linear dynamic impact analysis was performed in which a rigid object struck the central incisor at a speed of 5 m/s. The stresses were evaluated by the modified von Mises criteria and the strains were also recorded. RESULTS: Statistically significant differences were observed for elastic modulus values (p < .001). Mean and standard deviation values (MPa) without thermocycling were: Bioart (34.5 ± 0.9), Erkodent (15.0 ± 0.4), Polyshok (17.3 ± 0.4), Proform: (20.6 ± 0.8); and with thermocycling: Bioart (25.4 ± 0.8), Erkodent (10.7 ± 0.5), Polyshok (13.3 ± 0.6), Proform (13.1 ± 0.6). The thermocycling process reduced stress and strain levels regardless of the mouthguard materials. Shock absorption ability calculated based on the strain values was increased with thermocycling process. CONCLUSION: The thermocycling process, regardless of the commercial brand, reduced the stress/strain and increased the shock absorption ability of mouthguards.

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BACKGROUNDS/AIMS: Traumatic dental injuries with bone fractures require rigid splinting. The degree of rigidity of the wire-composite splints can be challenging. The aim of this study was to evaluate the effect of the rigidity of different wire-composite splints on alveolar process displacement. MATERIAL AND METHODS: A model was created using polystyrene resin to simulate the anterior maxilla, bovine incisors to simulate maxillary incisors, and polyether impression material to simulate the periodontal ligament. An alveolar process fracture was created, while maintaining the labial bone connection with the PDL. Four wire-composite splints (0.3, 0.6, 0.9, and 1.2 mm in diameter) were compared with models without splints and with no fracture (n = 5). The alveolar process displacement was measured (3 times per model/per splint type) at the fractured and adjacent central incisor regions using a deflectometer (Instron) under functional cycling and static loading (100 N). Data (µm) were analyzed using RM ANOVA, followed by Tukey's HSD test (α = 0.05). RESULTS: The displacement at the region of the adjacent incisor was not influenced by the splint during static and cycling load (P > .05). The Tukey test demonstrated that the model without splints had significantly higher alveolar process displacement at the traumatized teeth than that of all other splint models (P < .001). Increasing the wire diameter from 0.3 mm to 0.9 mm significantly reduced the alveolar process displacement (P < .001). No difference was observed between the 0.9 mm (P = .123) and 1.2 mm (P = .219) wire-composite splints irrespective of the measured tooth regions. CONCLUSIONS: The rigidity of the wire-composite splint significantly influenced the mobility of the fractured alveolar process. The use of at least 0.9 mm wire was effective in reducing the fractured alveolar process displacement to a level that was similar to the adjacent teeth.

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BACKGROUND/AIM: There are few studies in the literature evaluating possible alterations in laboratory tests in patients with maxillofacial fractures. The aim of this study was to analyze the changes in admission laboratory tests of patients with maxillofacial fractures with indications for surgical treatment, including the influence of dento-alveolar trauma. MATERIAL AND METHODS: Data from complete blood counts, blood coagulation tests, blood chemistries, and urinalysis results were obtained. The occurrence of concomitant dento-alveolar trauma was noted. The medical records were also re-evaluated later to verify the treatment outcome and the occurrence of complications. Statistical analyses were performed using the likelihood-ratio test to verify significant changes in the evaluated parameters (P ≤ .050). RESULTS: There was a prevalence of males (78%) with a mean age of 35.9 years. Lower erythrocyte counts, hemoglobin levels, and/or hematocrit were observed in males with associated fractures and with simultaneous dento-alveolar fractures. Higher mean neutrophil, segmented neutrophil, and lymphocyte counts were observed in patients with simultaneous dento-alveolar trauma. A higher mean activated partial thromboplastin time (aPTT) ratio was also observed. Lower potassium levels were observed for patients in the fourth decade of life. Higher leukocyte counts not associated with trauma were observed in the urinalysis results of females and in the group of patients aged 20 or younger. Verification of treatment outcome showed two cases of infections and two cases that needed re-operation after mandible fractures. These four cases showed no significant changes in laboratory tests regarding the predisposition for complications. CONCLUSION: Patients with maxillofacial fractures had neutrophilia, increased aPTT, and non-traumatic leukocyturia. There was an influence of associated fractures and dento-alveolar trauma on the decrease in red blood cell parameters, neutrophilia, and lymphocytosis and of age on hypokalemia.

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Introduction and Objective: The aim of this study was to investigate whether the sequelae arising from dental trauma in permanent teeth were influenced by the use or non-use of a clinical protocol, in emergency care treatment facilities in the city of Joinville/SC, Brazil. Material and methods: From 2008 to 2010, a total of 70 dental records were reviewed and evaluated 6 months after the completion of treatment. In addition to the data relating to gender, age, etiology, most affected teeth, and most prevalent traumas, the individuals were divided into 2 groups to compare the sequelae observed following either the use or non-use of a clinical protocol for dental trauma treatment. Results: There was a greater incidence of male patients, particularly in the age-range of 8 to 15 years. Falls were the most frequent cause of trauma. The total success rate of the emergency care was of 78.57%. In the group in which the protocol was used, the success rate reached 88.89% compared to 60.0% in the group in which the protocol was not used. Conclusion: The use of a clinical protocol positively influenced the sequelae arising after treatment for dental trauma.