Comparison of root dentin damage induced by three techniques for cast post removal

Aim: To investigate root dentin defects induced by different cast post removal tech-niques. 

Methodology: One hundred bovine incisors were standardized to 15 mm. Twenty roots served as unprepared controls; the remaining 80 were instrumented with the BioRace system (to size 40/.04), obturated using lateral condensation, and prepared for post space with #1-4 Largo drills. Of these, 60 received directly fabricated cast posts cemented with zinc phosphate. Post removal was performed using ultrasonic vibration, a carbide bur, or a spring-activated device. Roots were sectioned at 4, 8 and 12 mm from the apex and examined at 25× magnification to assess the presence of fractures and other dentinal defects (partial cracks and craze lines). Data were  analyzed with the Chi-square test (α = 0.05) and Bonferroni-adjusted pairwise z-tests.

Results: Among 300 sections, 103 (34.3%) showed defects. The control group showed none. All removal techniques produced defects, with no significant difference among protocols for other defects (P>0.05). The spring-activated device was asso-ciated with a higher number of root fractures (P<0.05). Defects distribution was similar across root levels (4, 8 and 12 mm).

Conclusions: All techniques caused dentin damage. Only the spring-activated device increased fractures. Careful selection of the removal strategy is advised.