Effect of access cavity preparation design on fracture strength of teeth- An in vitro study

Access cavity (AC) preparation is a fundamental measure in endodontic therapy, significantly affecting the treatment’s long-term success by ensuring thorough cleaning and shaping of the canal morphology. Design of the access cavity influences the structural integrity and fracture resilience of treated teeth. This study aims to evaluate the influence of distinct access cavity patterns—Traditional/Conventional and Buccal/Cervical—focusing on the fracture endurance of teeth, providing insights to optimize clinical outcomes.

The study utilized freshly extracted maxillary and mandibular central incisors, and mandibular premolars. Teeth were allocated into three groups: a control group with intact teeth, and two experimental groups with Traditional/Conventional and Buccal/Cervical access cavity preparations. Root canal treatments were performed, followed by fracture strength testing using a custom device. The fracture strength was documented in newtons, and data interpretation was done by one-way ANOVA and unpaired t-tests.

The results indicated that the control group exhibited higher fracture toughness measured against the trial subjects. Within the trial subjects, teeth with Traditional/Conventional access cavities demonstrated greater fracture resistance than those with Buccal/Cervical access cavities. However, the difference was statistically significant only in maxillary central incisors, and not in mandibular central incisors or mandibular premolars.

The study concludes that while Traditional/Conventional access cavity design offer better fracture resistance, the choice of cavity design should be tailored to the specific tooth and clinical scenario. The labial access cavity, though not superior in fracture resistance, can be considered an alternative when indicated, particularly in anterior teeth.