Assessment of Factors Affecting Partial Removable Dental Prostheses Framework Fit: A Clinical Prospective Study

Purpose: To prospectively evaluate the effects of impression material, impression tray type, and partially dentate arch classification on the accuracy of fit of partial removable dental prostheses (PRDP) cobalt-chromium (Co-Cr) frameworks, as inferred from the number of fabricated frameworks required for achievement of acceptable fit. Materials and Methods: A total of 103 partially dentate patients provided with Co-Cr PRDP treatment for one or both arches (n = 142) by undergraduate dental students were clinically assessed by two examiners at the metal framework try-in stage, and the relevant data were recorded. Statistical analyses of data were performed using factorial analysis of variance (ANOVA) to study the associations of impression material (alginate, polyvinyl siloxane [PVS]), Kennedy class, and impression tray type (stock, custom) with the number of frameworks that needed to be fabricated for each patient (α = .05). Results: Statistical analyses of data derived from 142 (65 maxillary and 77 mandibular) treated partially edentulous arches revealed no significant correlation between the impression material, Kennedy class, or tray type with respect to the number of framework construction attempts needed (P ≥ .05). Post hoc Tukey test also did not demonstrate any significant differences between the different Kennedy classes in relation to the set outcome measure (P ≥ .05). Conclusion: Alginate as an alternative option to PVS and modified metal stock trays can be used for making final impressions to produce PRDP Co-Cr frameworks. Framework fit is unaffected by class of partial edentulism (Kennedy class).