title: Fracture Resistance of Endodontically Treated Maxillary Premolars Restored by Various Direct Filling Materials: An In Vitro Study.
abstract: The aim of this study is to compare the effect of various restorative materials on fracture resistance in maxillary premolars. Premolars (n = 64) with no restorations or cracks were selected. MOD cavities were prepared considering the buccolingual width to be equal to half of the intercuspal distance. The specimens were randomly divided into 8 groups, 8 specimens each: group A intact teeth, group B unfilled cavity, group C composite made by oblique layering technique, group D composite with 2 mm cusp coverage, group E bulk-filled posterior composite, group F glass-ionomer, group G amalgam, and group H composite with proximal boxes. The specimens were subjected to an axial compression load with the mean values of fracture resistance in group A: 1289 N, group B: 181.75 N, group C: 445.38 N, group D: 645.88 N, group E: 355.13 N, group F: 352.00 N, group G: 191.38 N, and group H: 572.00 N. There was no significant difference between groups B and G, between C and D, E, and F, and between group D and H. All other measurements were statistically significant. We conclude that composite restoration with cusp coverage is the most ideal nonprosthetic solution for endodontically treated teeth. Cusp coverage increases the fracture resistance compared to the conventional cavity design.
authors.affiliation: Private Dental Practice, Vystavby 3, 040 11 Kosice, Slovakia.
authors.forename: Jozef
authors.initials: J
authors.lastname: Mincik
authors.affiliation: Mint Dental, Private Dental Practice, Ostravska 8, 040 11 Kosice, Slovakia.
authors.forename: Daniel
authors.identifier: 0000-0002-0076-572X
authors.initials: D
authors.lastname: Urban
authors.affiliation: Department of Dentistry and Maxillofacial Surgery, Faculty of Medicine, Pavol Jozef Safarik University, Rastislavova 43, 040 11 Kosice, Slovakia.
authors.forename: Silvia
authors.initials: S
authors.lastname: Timkova
authors.affiliation: First Department of Dentistry, Faculty of Medicine, Pavol Jozef Safarik University, Trieda SNP 1, 040 11 Kosice, Slovakia.
authors.forename: Renata
authors.initials: R
authors.lastname: Urban