A Comparative Evaluation of the Retention of Denture Bases fabricated using Selective Pressure, Massad's and Functional Impression Techniques: A Clinical Study

Abstract

Background: Impression techniques have evolved considerably during the last decade. However, it needs to be assessed whether the retention achieved with these techniques is adequate enough to establish them as an alternative to the conventional techniques.Purpose: This study was planned to evaluate the retention of denture bases fabricated using the selective pressure, functional and Massad's impression techniques. Materials and methods:Twenty completely edentulous patients were selected and each of them was subjected to three definitive impression techniques: selective pressure, functional and Massad's techniques. The permanent bases were fabricated and checked for retention with a custom made retention checking apparatus. The load required to dislodge the denture base fabricated using each technique, from the maxillary foundation was recorded and this data was subjected to statistical analysis.Results: The statistical analysis shows that the difference between the selective pressure and the functional impression technique is statistically significant (p = 0.046) However, this result needs verification by collecting more data or designing another study, since the observed p-value is closer to the significance level (i.e. 0.05). Though the difference between the means of Massad's and functional techniques is of 39 gm, it is statistically not significant (p = 0.09). The difference between means load to dislodge denture bases for selective pressure and Massad's techniques (5.5 gm) is not statistically significant (p = 0.95). Conclusion:The three impression techniques yielded adequately retentive permanent denture bases. However, retention of the denture bases obtained from the selective pressure impression technique was best, followed by the Massad's and functional techniques. Clinical implication:The results of this study indicated that the denture bases fabricated using selective pressure impression technique were more retentive than the Massad's and the Functional impression technique.