Background: The impression process includes careful transfer of the patient's soft and hard tissues to laboratory and is a major part of fixed prosthetic treatments.The impression technique determines the restoration of finish line. Moreover, the significance of margin in the longevity of restoration and the effect of impression technique on marginal adaptation of restoration indicate the necessity of applying an accurate impression technique. Aim of the study: To compare one-step technique and two-step technique for making impressions using polyvinylsiloxane for FPD. Materials and methods: The present study was conducted in the Department of Dentistry, Shridevi Institute of Medical Sciences and Research Hospital, Tumkur, Karnataka, India. We selected 35 patients reporting to the Department clinic for fixed partial denture (FPD) as their dental treatment for the study group. The age of the subjects ranged from 22- 60 years. For each patient, two different techniques with polyvinylsiloxane impression material were performed for making master impression. The techniques were i) technique 1 was single stage double mix technique; and technique 2 was two stage technique with spacer. Results: We observed that number of patients with defects in Technique 1 were 14 and in technique 2 were 15. The most common defect was voids in impression in both the techniques. The results on comparison were observed to be statistically non-significant (p>0.05). Conclusion: The one step technique and two-step technique using polyvinlylsiloxane are equally effective for impression making. The impression voids are most commonly seen defects seen in the impression by both the techniques.
Key words: Polyvinylsiloxane, impression, Fixed partial denture.