A NEW METHOD FOR EVALUATING SPLINT SYSTEMS USED IN DENTAL TRAUMATOGY

Introduction: At the age of 16 years, the 35% of subject have sustained dental trauma and this percentage rises to 50% by the age of 18. This traumas can involve both the primary and permanent dentition. Nevertheless, the former are mainly lesions of the supporting periodontal tissue, whereas traumas involving the hard dental tissues are more frequently observed in the permanent dentition. From a prognostic standpoint, traumas involving periodontal structures have more unpredictable outcomes of periodontal ligament. To achieve the restituito ad integrum of this, a contention device or splint is employed for fixation of mobile or dislocated part. This splint reduces the load exerted on each tooth by distributing the masticatory and perioral muscle forces on multiple teeth and a broader surface. Several splints are used in clinical practice, but, independently of the type, passivity and flexibility are essential qualities for the physiological movement of the traumatized tooth to promote healing of the periodontal fibres. The aim of this study is to compare the flexibility off ive different splints through in vitro assessment of their degree of rigidity, espresse by the movement allowed to the spinte teeth. Material and Method: A resin cast of the upper arch was made and the stress analyses were performer on preformed resin teeth. All teeth were fixed on the cast with the exception of the three front one , which could be removed and replaced. To simulate the form and characteristics of the periodontal ligament polyvinyl siloxane was placed at the apical level ( thickness 3 mm to allow a small verical movement) and around the root (thickness 0.3 mm) of 11, 12 and 21. The load was applied to 11, previously spinte to 12 and 21, as there are no benefits in extending the splinting. To asses the rigidity of the five splints, stress analyses are performed using an universal machine, that applies an increasing linear force measured in Newtons (N) at the incisal margino f tooth 11. Results and Conclusions: For each splint, the mean of the movements recorded at 50 N and a at 30 N was recorded. To asses the rigidity of the examined splints, the deformation energy (E) was calculated both for the stress and movement analyses. This study provides experimental data on the flexibility of different splint systems commonly used in clinical practice to allow a certain degree of mobility to traumatized teeth to promote optimal healing of the periodontal tissues.