OBJECTIVES: To compare cutting resistance of 7 core build-up materials with medium-grit diamond burs using an air rotor mounted in a precision custom designed substrate cutting device.
METHODS: 56 specimens (n=8) were prepared using a split Teflon mold following manufacturers' instructions and light cured (1100mW/cm2, Elipar S10/3M). Specimens (length=17mm/width=12mm/height=4mm) were weighed (Adventurer SL/O'Haus) and placed on a sliding platform in a custom designed cutting device with a computer controlled milling head which regulated air and water volume as well cutting speed at a constant value. The cuts in each restorative material were made using a high speed air rotor (20000rpm) to a depth of 2.5mm for 5 minutes. A 200 gram weight pulled the specimen, mounted on a slide against the rotating cutting diamond. After cutting, the specimens were ultrasonically cleaned (in distilled water/10min), dried (vacuum/1hour) and weighed again. Each diamond bur was used to cut 4 specimens for each material. All burs were ultrasonically cleaned in alcohol for 15 minutes after each cut. Temperature and humidity were recorded during the specimen preparation (26ºC/34%). Data were analyzed using ANOVA and Tukey/Kramer post-hoc analysis (p=.05).
RESULTS: (n=8) (Mean±SD) Materials with the same letter are not statistically different.
Materials/Manufacturer | Cut length (mm) | Weight loss (gr) | %Weight loss |
NDT* Derived CBU/Septodont | 1.2±0.1 A | 0.004±0.001 A | 0.3±0.07 A |
Absolute Dentin/composite/Parkell | 2.0±0.5 B | 0.013±0.003 B | 0.8±0.2 B |
Core Paste XP/composite/DenMat | 1.9±0.4 B | 0.012±0.003 B | 0.7±0.2 B,D |
Fluorocore 2+/composite/L.D.Caulk | 1.2±0.2 A | 0.006±0.001 A,D | 0.3±0.06 A,D |
Fuji IX/Resin Modified glass Ionomer/GC America | 6.1±1.4 C | 0.063±0.013 C | 3.4±0.9 C |
Luxacore/Composite/DMG | 1.3±.0.3 A | 0.007±0.002 D | 0.5±0.1 D |
Valiant/amalgam/Ivoclar | 3.6±0.8 D | 0.168±0.028 E | 4±0.7 C |
*Nano-Dimer Technology
CONCLUSIONS: Composite materials have greater cutting resistance than amalgam and resin modified glass ionomer. Supported in part by a grant from Septodont.