Structural integrity of extracted teeth restored using three different post-and-core systems: An in vitro comparative...

Area of Science:

• Dental Materials Science
• Restorative Dentistry
• Biomaterials Engineering

Background:

• Endodontically treated teeth often require post-and-core restorations to regain structural integrity.
• Various post-and-core materials exist, each with distinct mechanical properties and clinical outcomes.
• Assessing the fracture resistance of these materials is crucial for predicting long-term clinical success.

Purpose of the Study:

• To evaluate and compare the in vitro fracture resistance of endodontically treated mandibular premolars restored with different post-and-core materials.
• To determine which post-and-core material offers the greatest resistance to structural failure.

Main Methods:

• Thirty-six extracted human mandibular premolars were divided into four groups: cast metal post-and-core, milled zirconia post-and-core, prefabricated post with composite resin core, and a control group.
• Samples were subjected to a load-to-fracture test using a universal testing machine.
• Fracture resistance data were statistically analyzed using ANOVA and Fisher's exact test.

Main Results:

• The milled zirconia post-and-core group exhibited the highest mean fracture resistance (1567.26 ± 317.66 N).
• The cast metal post-and-core group showed the second-highest resistance (1355.92 ± 621.56 N), followed by the prefabricated post with composite resin core group (725.67 ± 251.05 N).
• Statistical analysis indicated no significant differences in fracture resistance among the tested groups (P = 3.77).

Conclusions:

• Milled zirconia post-and-core systems demonstrated the highest mean fracture resistance, suggesting superior robustness for endodontically treated teeth.
• Cast metal post-and-core restorations resisted greater stress loads than fiber-reinforced posts.
• Zirconia restorations exhibited a more favorable fracture mode compared to other tested materials.