IADR Abstract Archives
Characteristics of polymer based CAD/CAM Blocks for permanent restorations
Objectives: Analysis of hybrid and polymer based CAD/CAM blocks with respect to mechanical strength, water uptake and filler load.
Methods: As reference concerning mechanical strength and modulus of elasticity a Leucite ceramic, IPS Empress CAD(IPS , IvoclarVivadent) was selected. For a hybrid material Vita Enamic (VE, Vita Zahnfabrik) and as polymer based materials Lava Ultimate (LU, 3MEspe),Coltene Experimental (CEX, Coltene AG) , Cerasmart (CS, GC Corporation) and HC (HC, Shofu) were selected. The samples were cut with an Isomet 1000 diamond saw from14L sized blocks.
Flexural strength and modulus of elasticity: Sticks with a dimension of 1x1x18mm were prepared. The sticks were stored in water for 24h at 37 °C. After storage a three point bending test (Zwick Z020, crosshead speed 0.5mm/min, span width 10 mm, n=7) was done. Flexural strength and modulus of elasticity was determined. Water uptake was done with discs (discs from block size 14L, thickness 1mm, n=5), according to ISO 4049. Data were analyzed with a one way ANOVA (p<0.05)
Filler content was determined (n= 3) by burning the organic components at a temperature of 700°C in the presence of air.
Results: Polymer based materials show an elasticity comparable or lower than human tooth structure. Flexural strength varies from 140 (VE ) to 198 (CEX).
Conclusions: Polymer based composite blocs for permanent restorations show equal or better mechanical strength than an established Leucite ceramic. Low modulus of elasticity could be a benefit for a full crown on tooth or implant. The water uptake of HC fulfills the ISO 4049 requirements, but seems to be very high for an Inlay preparation. Further investigations have to prove whether restorations made from polymer based CAD/CAM blocks are an alternative to ceramics.
Methods: As reference concerning mechanical strength and modulus of elasticity a Leucite ceramic, IPS Empress CAD(IPS , IvoclarVivadent) was selected. For a hybrid material Vita Enamic (VE, Vita Zahnfabrik) and as polymer based materials Lava Ultimate (LU, 3MEspe),Coltene Experimental (CEX, Coltene AG) , Cerasmart (CS, GC Corporation) and HC (HC, Shofu) were selected. The samples were cut with an Isomet 1000 diamond saw from14L sized blocks.
Flexural strength and modulus of elasticity: Sticks with a dimension of 1x1x18mm were prepared. The sticks were stored in water for 24h at 37 °C. After storage a three point bending test (Zwick Z020, crosshead speed 0.5mm/min, span width 10 mm, n=7) was done. Flexural strength and modulus of elasticity was determined. Water uptake was done with discs (discs from block size 14L, thickness 1mm, n=5), according to ISO 4049. Data were analyzed with a one way ANOVA (p<0.05)
Filler content was determined (n= 3) by burning the organic components at a temperature of 700°C in the presence of air.
Results: Polymer based materials show an elasticity comparable or lower than human tooth structure. Flexural strength varies from 140 (VE ) to 198 (CEX).
Conclusions: Polymer based composite blocs for permanent restorations show equal or better mechanical strength than an established Leucite ceramic. Low modulus of elasticity could be a benefit for a full crown on tooth or implant. The water uptake of HC fulfills the ISO 4049 requirements, but seems to be very high for an Inlay preparation. Further investigations have to prove whether restorations made from polymer based CAD/CAM blocks are an alternative to ceramics.