{'fraction_non_alphanumeric': 0.03849518810148731, 'fraction_numerical': 0.020122484689413824, 'mean_word_length': 4.72, 'pattern_counts': {'":': 0, '<': 2, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
In vitro comparison of fracture strength of experimental hollow and solid design zirconia dowels.

PURPOSE
The aim of this study was to evaluate the fracture strength of experimental hollow and solid design zirconia dowels.


MATERIALS AND METHODS
Three types of dowels (fiber-reinforced composite [FRC], hollow design, and solid design zirconia dowels) were tested in the study (n = 10). A three-point bending method was conducted, and a load was applied until fracture. The values were recorded as Newtons (N) and then converted to megapascals (MPa) according to the diameter of the dowels. Statistical analyses were performed using one-way ANOVA and Tukey HSD tests. The significance was set at p < 0.05.


RESULTS
The mean fracture strength of the hollow design zirconia dowels was significantly higher (960.72 MPa) than solid zirconia dowels (741.78 MPa) and FRC dowels (687.64 MPa) (p < 0.05).


CONCLUSIONS
The hollow design zirconia dowel seems to have sufficient fracture strength for anterior restorations. This design may be beneficial to access the apical region when retreatment is necessary, without any dowel-removing procedure.