Accuracy of conventional versus additive cast-fabrication in implant prosthodontics: A systematic review and meta-analysis of in vitro studies

Purpose: Additive cast-fabrication has yet to be used as commonly in implant prosthodontics as conventional methods. This review aimed to investigate the accuracy of additive cast-fabrication in implant prosthodontics.

Study selection: The study protocol was registered in the PROSPERO database (CRD42022374972). Reporting was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines, following the Cochrane Handbook. Two-arm interventional studies that matched the PICO were included (Population: dental typodonts with implants, Intervention: additive cast-fabrication, Comparator: conventional cast-fabrication, Outcome: positional deviations). A systematic search was conducted in three databases: PubMed (MEDLINE), EMBASE, and the Cochrane Library (CENTRAL).

Results: Seven papers were included in the analysis of horizontal, vertical, and root mean square (RMS) deviations. No significant differences were observed between groups. The overall vertical mean deviation of the intervention group was -4.15 µm [-24.88; 16.57], and the pooled mean absolute deviation was 22.43 µm [8.33; 36.54]. In the control group, these values were 19.67 µm [-32.71; 72.04] and 24.62 µm [0.00; 59.42], respectively. The overall horizontal mean deviation in the intervention group was 21.29 µm [-77.10; 119.68], and the pooled mean absolute deviation was 26.96 µm [0.00; 70.81]. In the control group, the overall mean was 1.45 µm [-32.26; 35.15] and the pooled mean absolute deviation was 25.05 µm [9.08; 41.01]. The mean RMS was only slightly larger in the intervention group, with the value of 14.74 µm [-107.26; 136.74].

Conclusions: Additive cast-fabrication is as accurate as the conventional method for the position of implant analogs.