Fracture resistance of premolar teeth with class II preparations restored with light cured composite with beta quartz inserts, light cured' composite and silver amalgam in comparison with intact unrestored teeth - An in vitro study

An vitro study was designed to evaluate the fracture resistance of maxillary premolars with class II disto occlusal preparations restored with light cured composite with beta quartz' inserts, light cured composites layered incrementally, and silver amalgam in comparison with intact and unrestored teeth. Sixty freshly extracted maxillary premolars were randomly divided into 6 groups of 10 teeth each. All the 60 specimens were then subjected to a compressive load in an Universal Testing Machine (Hounsfield). The loads required to fracture the teeth were recorded and the data, obtained were subjected to statistical analysis and the following results were arrived, Teeth restored' with light cured composite with beta quartz insert showed higher values than light cured composite placed in horizontal increments. The use of the megafiller increased the filler-resin ratio and reinforced the tooth. Composite with, beta quartz, inserts was more resistant to tooth fracture than silver amalgam. Teeth restored with light cured composite incrementally placed in oblique layers. Produced a higher fracture resistance than any other group and showed the closest value to the intact teeth. This was followed in descending order by light , cured composite with beta quartz inserts, silver amalgam and light cured composite placed in horizontal increments. As a class II restorative material silver amalgam exhibited greater fracture resistance than bulk composite resin placed in horizontal increments.