[PPS-O-3] Evaluating the connectors parameters for the fracture strength of all-ceramic resin bonded bridges
[Abstract]
Objective:
All-ceramic resin bonded bridges (RBB) have gained popularity due to the minimal invasive concept and fulfils the aesthetic demand. Connector component in an RBB is the most critical area with minimal dimensions receiving occlusal load. This study aimed to evaluate and compare the fracture toughness of two commonly used all-ceramic material with different connector dimensions.
Method:
40 extracted human incisal teeth were used as the abutment for the RBB. Zirconia (Zir) and lithium disilicate (LD) were fabricated in a form of anterior RBB cantilever (n:20). For each material, 4 different connector parameters were tested (n:5). 40 RBB were cemented and tested with load to fracture. Type of fracture failure were observed and classified as favorable and unfavorable. A two-way ANOVA was used to analyze the result. For the FEA, CBCT of a master model comprised abutment tooth with cemented RBB was taken. A 3D models were established using the reverse engineering method and the CAD software used to assemble the RBB model with different material and shapes of the connector. Simulation load of 150N and 200N were tested and the stress and strain were recorded.
Results and Discussion:The highest fracture toughness was trapezoidal shape with max volume Zir 269±27N and LD 180±83N. The lowest value was trapezoidal min volume Zir 237±52N and LD 116±25N (Fig 1). The two-way ANOVA revealed a statistically significant interaction and Post-hoc Tukey showed no significant of the different connectors dimension in the same material but significant differences between material. Favourable failure upon loading was observed in 80% Zir and 100% LD. FEA exhibited varied stress pattern obtained from different models. The location of the maximum stress pattern changes according to the dimensions of the connector (Fig 2). Within the limitation of the present study, it can be concluded that ceramic type and connector dimensions have an impact on the structural integrity of the RBB framework upon occlusal loading.
References:
1. Alraheim IA. Five-year success rate of resin-bonded fixed partial dentures: A systematic review. Journal of Esthetic and Restorative Dentistry. 2019, 31, 40–50.
2. Kwon SJ, Lawson NC, McLaren EE et al. Comparison of the mechanical properties of translucent zirconia and lithium disilicate. J. Prosthet. Dent. 2018, 120, 132–137.
Objective:
All-ceramic resin bonded bridges (RBB) have gained popularity due to the minimal invasive concept and fulfils the aesthetic demand. Connector component in an RBB is the most critical area with minimal dimensions receiving occlusal load. This study aimed to evaluate and compare the fracture toughness of two commonly used all-ceramic material with different connector dimensions.
Method:
40 extracted human incisal teeth were used as the abutment for the RBB. Zirconia (Zir) and lithium disilicate (LD) were fabricated in a form of anterior RBB cantilever (n:20). For each material, 4 different connector parameters were tested (n:5). 40 RBB were cemented and tested with load to fracture. Type of fracture failure were observed and classified as favorable and unfavorable. A two-way ANOVA was used to analyze the result. For the FEA, CBCT of a master model comprised abutment tooth with cemented RBB was taken. A 3D models were established using the reverse engineering method and the CAD software used to assemble the RBB model with different material and shapes of the connector. Simulation load of 150N and 200N were tested and the stress and strain were recorded.
Results and Discussion:The highest fracture toughness was trapezoidal shape with max volume Zir 269±27N and LD 180±83N. The lowest value was trapezoidal min volume Zir 237±52N and LD 116±25N (Fig 1). The two-way ANOVA revealed a statistically significant interaction and Post-hoc Tukey showed no significant of the different connectors dimension in the same material but significant differences between material. Favourable failure upon loading was observed in 80% Zir and 100% LD. FEA exhibited varied stress pattern obtained from different models. The location of the maximum stress pattern changes according to the dimensions of the connector (Fig 2). Within the limitation of the present study, it can be concluded that ceramic type and connector dimensions have an impact on the structural integrity of the RBB framework upon occlusal loading.
References:
1. Alraheim IA. Five-year success rate of resin-bonded fixed partial dentures: A systematic review. Journal of Esthetic and Restorative Dentistry. 2019, 31, 40–50.
2. Kwon SJ, Lawson NC, McLaren EE et al. Comparison of the mechanical properties of translucent zirconia and lithium disilicate. J. Prosthet. Dent. 2018, 120, 132–137.