Compressive strength of endodontically treated mandibularpremolars rehabilitated with three techniques

The biomechanical rehabilitation of endodontically treated premolars with extensive mesio-occlusodistal (MOD) cavities is a clinical challenge due to their increased susceptibility to fracture.

To compare the compressive strength of endodontically treated mandibular premolars restored using different post-endodontic reconstruction protocols, using intact teeth as a reference for maximum mechanical performance.

Forty single-rooted premolars were distributed into four groups: one control group with no interventions, and three experimental groups with standardized mesio-occluso-distal (MOD) preparations. Experimental groups were restored respectively with core buildup, glass fiber posts, and polyethylene fiber reinforcement. After final composite resin restoration, specimens were tested for compressive strength using an INSTRON 1011 universal testing machine. Data were analyzed using the Kruskal-Wallis test (p<0.05).

When examining median (95%CI) compressive strength in Newtons (N), the highest value was found in the control group with 557.4 N (100.8-574.8), followed by the polyethylene fiber group with 471.4 N (194.2 to 565.5), the glass fiber posts group with 427.5 N (146.3 to 495.4) and the core buildup group with 345.1 N (216.8 to 574.9), (p = 0.84).

Under the experimental conditions of the present study, the compressive strength of endodontically treated mandibular premolars did not differ significantly among the evaluated reconstruction protocols. Although polyethylene fiber reinforcement showed a tendency toward higher resistance values, the results do not enable the establishment of conclusive mechanical advantages among the restorative systems assessed.