Assessment Of Radicular Dentin Preservation And Procedure Time Following Fiber Post Removal Using Different Treatment Techniques

Abstract

Objective

This in-vitro study investigated the effect of three fiber post-removal approaches - ultrasonic instrumentation, rotary post drilling, and guided rotary drilling - on radicular dentin preservation, residual fiber post and resin cement, and the time required for post removal. Cone-beam computed tomography (CBCT) was used to assess changes in dentin thickness and the presence of residual material before and after the intervention.

Materials and Methods

Forty-eight freshly extracted human mandibular first molars were selected according to predefined eligibility criteria. The distal roots were endodontically treated, prepared for fiber post placement, and restored with glass fiber posts cemented using a self-adhesive resin cement. The specimens were randomly assigned to three groups (n = 16) according to the post-removal technique. Group A underwent ultrasonic removal, Group B underwent removal with a rotary fiber post drill, and Group C underwent removal with the same rotary drill under a 3D-printed guiding template. CBCT scans were obtained before and after post removal. Changes in dentin thickness were determined at coronal, middle, and apical root levels. Residual fiber post and resin cement were assessed using a binary scoring system, and active post-removal time was recorded.

Results

The three techniques differed significantly in their effects on radicular dentin preservation, residual material, and removal time. The guided rotary technique produced the smallest amount of dentin removal at most evaluated root surfaces and levels. Ultrasonic instrumentation resulted in significantly greater dentin loss than both rotary techniques. Conversely, ultrasonic removal produced the lowest residual fiber post and resin cement scores. The ultrasonic technique required the longest mean removal time (102.38 ± 9.47 s), whereas the unguided and guided rotary techniques required 33.63 ± 3.88 s and 28.94 ± 1.73 s, respectively. The difference between the guided and unguided rotary techniques in removal time was not statistically significant.

Conclusions

Within the limitations of this laboratory study, guided rotary fiber post removal demonstrated the most favorable combination of radicular dentin preservation and procedural efficiency. Ultrasonic instrumentation provided more effective removal of residual post and cement material but was associated with greater dentin removal and a considerably longer procedure time. The choice of removal technique should therefore consider the balance between preservation of root structure and completeness of post-space cleaning.