Posterior Dişlerin Restorasyonunda Kullanılan Bir Cam Hibrit Restoratif Sistemin Mekanik Özelliklerinin Değerlendirilmesi

Abstract

The aim of this in vitro study was to evaluate mechanical properties of a glass hybrid restorative system (EQUIA Forte/GC) and compare with a microhybrid composite resin (G-aenial Posterior/GC). For compressive strength test, cylindrical specimens with 4 mm diameter 8 mm height were prepared (n=12). The specimens were subjected to loading on a Universal testing machine (Mod Dental, Ankara, Turkey) (crosshead speed 1 mm/min) until fracture occurred after storing 24 hours in distilled water at 37°C. Forty eight sound extracted human mandibular molars were used for fracture strength test. Teeth were randomly divided into four groups; Group 1 (Positive control): Sound teeth, Group 2 (Negative control): Extended size Class 2 cavities prepared on mesial surfaces of teeth, Group 3: Extended size Class 2 cavities restored with microhybrid composite resin according to manufacturer’s directions. Group 4: Extended size Class 2 cavities restored with glass hybrid according to manufacturer’s directions. Specimens were then thermocycled for 10000 cycles between 5°C and 55°C and subjected to loading on universal testing machine until fracture occurred. Maximum force before failure (Newton) was recorded. Data were analyzed using Mann-Whitney U, Kruskal Wallis and Tukey HSD tests (α=0.05). Fracture modes were investigated with Scanning Electron Microscope. Mean compressive strength values of the composite resin and glass hybrid restorative material were 178.20 ± 17.34 MPa and 64.62 ± 25.72 MPa, respectively (p<0.05). Mean fracture strength values were significantly higher in sound teeth group (977.99 ± 92.79 N) than the other groups. No statistically differences were observed between fracture strength of groups restored with composite resin (961.87 ± 246.04 N) and glass hybrid (641.88 ± 274.57 N) (p>0.05). Fracture modes of all specimens were repairable in composite resin group, whereas 2 specimens had non-repairable fractures in glass hybrid group. Glass hybrid restorative system could be preferred for extensive caries lesions on posterior teeth as an alternative to composite resins.