Comparative Assessment of Retentive Characteristics of Nylon cap versus Retention.Sil in Ball-Retained Mandibular Implant Overdentures. A Randomized Clinical Trial

PURPOSE: The purpose of this study was to clinically evaluate retentive characteristics of Retentive.Sil 600 attachment system and to compare it to that of Nylon cap in ball- retained mandibular implant overdentures.
Materials and Methods : Fourteen completely edentulous patients were included for this trial; seven patients /group following strict inclusion and exclusion criteria. The participants were randomly allocated to receive either nylon cap (control group) or Retention.Sil (intervention group) on ball abutments to retain 2-midsymphseal mandibular implant overdentures. Retention values of both attachment systems were evaluated in Newtons (N), at baseline during time of denture insertion and thereafter at 3, 6, 9 and 12 months follow-up periods. Further the effect of time on retentive characteristics of both attachment systems was evaluated. The data was tabulated and statistically analysed using SPSS software.
Results: Nylon cap showed significantly higher mean retention values compared to Retention.Sil group at each of the observation periods P ≤0.05. In nylon caps group, there was a significant, gradual increase in retention values by time except at 6 and 9 months follow-up periods where the increase was non-significant. In Retention.Sil 600 group, retention gradually decreased by time. This decrease was statistically significant (P=0.00).
Conclusions: Within the limitations of this study, it can be concluded that retentive characteristics of any given attachment system is changeable overtime. Retention.Sil could be attachment of choice for retaining mandibular overdentures if reduced denture retention is required in cases with poor manual dexterity or temporarily for replacement of nylon caps of stud attachments when subjected to wear. Gradual decrease in retention of Retention.Sil over time merits further investigation to evaluate the durability of the material over extended follow-up periods.