## 4 Discussion  
In the past, different approaches for evaluating splint rigidity have been used [18]. One of the advantages of in vivo investigations with patients is the presence of a natural PDL. However, the disadvantages of assessing splint rigidity in healthy individuals include the lack of increased tooth mobility, the risk of damaging sound enamel during splint removal, and the limited availability of test persons [2]. Therefore, in vitro studies using various types of models have also been conducted. The advantage of artificial models is that they are available anytime, the moderate inter-model variability compared to the patient, and the potential for intentional adjustment of tooth mobility. Besides, there is no risk of damaging sound enamel, as can happen in healthy individuals [13; 19]. The core objective of the present in vitro study was to assess the flexural strength and flexural modulus of different splint systems used for periodontal splinting. Flexural strength and flexural modulus are vital mechanical properties which were employed in earlier experiments to evaluate and compare the physical properties of the restoration and restorative materials [20; 21]. Reports from literature revealed that, in the past, mesh grids, wires and pins were frequently used with the adhesive systems for stabilization and splinting of teeth [22]. These splint materials stay in position just by mechanical locking around the restorative material that could lead to generation of shear planes and stress concentration and ultimately fracture of the composite with premature failure of the splint system. Newer and advanced splint systems, like bondable, polyethylene woven ribbons, have succeeded in overcoming the problems associated with older splint systems. Flexible splints such as the fiber-composite splint and polyethylene fiber used in the present study fulfill these requirements. For evaluating splint rigidity, objective tooth mobility assessment is required. The three-point bending test is a well-established tool used to evaluate flexural strength and flexural modulus in dental traumatology [18; 23]. Ribbond(r) is a leno weave, ultra-high-molecular-weight polyethylene fiber with an ultra-high elastic modulus. The specially designed fiber network permits wetting of the fibers and the infusion of the resin into the fiber network [24]. An in vitro study conducted by [PERSON] and [PERSON] showed that flexural strength and flexural modulus of Ribbond(r) was 153 MPa and 4.0 GPa, while in the current study it was 168.04 \(\pm\) 45.95 and 5.861 \(\pm\) 0.501 GPa, respectively [25]. In our study, the mean maximum load applied to Ribbond(r) splint group was 143.06 \(\pm\) 30.73N. Whereas, contradictory results were reported by [PERSON] et al. that showed mean fracture resistance of 919.86 \(\pm\) 47.67 N [26]. While the present study showed that F-splint-Aid has 131.95 \(\pm\) 16.48 MPa of flexural strength and 5.366 \(\pm\) 1.042 GPa of flexural modulus, respectively, which is significant less when compared with the study performed by [PERSON] and [PERSON] [25]. Composite and wire splints are one of the most commonly used splints in dental field and are flexible enough when the wire diameter is not more than 0.3-0.4 mm [27]. In the current research, it was observed that flexural strength and flexural modulus recorded by the wire composite splint are 122.95 \(\pm\) 8.72 MPa and 4.629 \(\pm\) 0.962 GPa, respectively. [PERSON] et al., in a clinical study, compared the efficacy of Ribbond(r) ribbon with stainless steel wire [28]. We concluded that Ribbond(r) was an excellent material for splinting mobile teeth relating to patient comfort, durability, resistance to fracture, biocompatibility, and esthetic acceptability. The result of the present study showed that the Ribbond(r) was found to have the highest flexural strength, followed by F-splint-Aid(r), ligature wire, InFibra(r), and composite block having the least flexural strength. The research carried out by [PERSON] and [PERSON] in 2011, [PERSON] et al.