Fracture Resistance of Various Temporary Crown Materials

Abstract

Aim:The aim of this study was to evaluate the fracture resistance of various provisional crown materials using an in vitro model test system. o Methods and Materials:In the present study polycarbonate crowns, prefabricated by the manufacturer (3M Polycarbonate Crown), and the temporary crowns, fabricated in the dental laboratory environment, were fabricated using bis-acryl composite (Protemp II), autopolymerizing PMMA resin (BISICO Temp S), and heatpolymerized PMMA resin (Major C&B-V Dentine). All temporary crowns were stored in distilled water for 24 hours at room temperature prior to testing. The crowns were seated on metal dies, fabricated from Cr-Co alloy (AZ Dental, Konstanz, Germany), and then tested using the indenter of a Hounsfield testing machine (Hounsfield Tensometer, Hounsfield Test Equipment, Raydon, England). The tip of the indenter was located at a position one-third of the way down the inciso-palatine surface at 135º. The data were statistically analyzed for differences using one-way analysis of variance (ANOVA) and the Tukey HSD test (P<.05). Additionally, the types of failure obtained from the fracture load test were examined using 10X magnification with a stereo microscope. Results:The results of the present study indicated polycarbonate crowns were significantly different from the BISICO Temp S, Protemp II, and Major C&B-V Dentine (P<.05) groups. Conclusion:This in vitro study shows polycarbonate crowns may be preferable to the other types of temporary o crowns used in this study.

Comparison of interim restorations fabricated by CAD/CAM with those fabricated manually

“…The load deformation curve was used to accurately mark the fracture point. 40 Cemented interim restorations were thermocycled (50 000 cycles, 5 to 60 C, and dwell time of 3 minutes) and immersed in methylene blue dye for 24 hours. Specimens were sectioned with a precision cutting machine (IsoMet 5000 linear precision saw; IsoMet Corp), and cut sections were examined under an optical microscope (SZ 11; Olympus Corp) at ×30 magnification to evaluate the extent of dye penetration.…”

Effect of an experimental silica-nylon reinforcement on the fracture load and flexural strength of bisacrylic interim partial fixed dental prostheses

“…The fracture load reported for bisacrylic-resin interim single crowns (380 N) is higher than that reported for bisacrylicresin FPDs. 21 Bisacrylic resin has been investigated in terms of flexural strength, fracture toughness, and combined mechanical properties, but no studies of the fracture load of bisacrylic resin FPDs have been conducted. 8,[22][23][24][25][26] Bisacrylic resin is a reliable material that yields satisfactory results in the tests to which it has been submitted, confirming that it is a good option for the fabrication of interim restorations.…”

Management of Provisional Restorations' Deficiencies: A Literature Review

“…Hence, it is important to know the flexural strength of various types of resins for provisional restorations, as most of them are brittle 47 . Despite conflicting reports in the literature, it is generally accepted that PMMAs exhibit higher fracture toughness than bisphenol A glycidyl methacrylate (bis‐GMA) resins 48–50 . Recently, the resins have become more widely used even though they are more prone to fractures when used in long‐span bridges.…”