Effect of temporary cement type and screw access channel filling on the dislodgement resistance of implant-supported copings: an in vitro study

Adequate retention of cement-retained implant restorations is essential while maintaining retrievability when clinical intervention is required. Although cement type is known to influence retention, the effect of different screw access channel filling levels and their interaction with cement type remains unclear. This in vitro study evaluated the effects of three materials used for temporary cementation and two standardized screw access channel filling levels on the dislodgement resistance of implant-supported copings. Ninety cobalt-chromium copings were fabricated and allocated to six groups ( n = 15) according to cement type (Cavex Temporary Cement, T Cem Implant, or Life Regular Set) and screw access channel filling level (complete or partial). Screw access channels were filled in complete-filling groups, whereas a 2-mm coronal portion remained unfilled in partial-filling groups. After cementation, specimens were loaded at 50 N for 10 min, stored for 24 h, and subjected to a pull-out test. Data were analyzed using two-way analysis of variance followed by Bonferroni-adjusted pairwise comparisons (α = 0.05). Cement type, screw access channel filling level, and their interaction significantly affected dislodgement resistance ( P < .001). The highest mean dislodgement resistance was observed in the T Cem Implant partial-filling group (425.49 ± 39.53 N), whereas the lowest was observed in the Cavex Temporary Cement complete-filling group (61.50 ± 11.59 N). No significant differences between complete and partial filling were detected for Cavex Temporary Cement (P = 1.000) or Life Regular Set ( P = .999). In contrast, partial filling produced significantly greater dislodgement resistance than complete filling with T Cem Implant ( P = .004). Under the present in vitro conditions, cement type and screw access channel filling level significantly influenced dislodgement resistance, and the effect of screw access channel filling level depended on the cement used. Partial screw access channel filling significantly increased dislodgement resistance with T Cem Implant but not with Life Regular Set or Cavex Temporary Cement.