Impression & Prosthesis Quality Made From Different Polyvinylsiloxane Impression Techniques

Study Overview
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Brief Summary
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This randomized controlled trial is to clinically assess and compare impression quality of polyvinylsiloxane impression material using one step (experimental) and two step (control) impression techniques and its effect on marginal fit of prosthesis and proximal contact of prosthesis.

Detailed Description
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Study participants will be randomly allocated to either of the two groups (experimental or control) through software-generated random numbers. Indicated tooth will be prepared to receive a fixed prosthesis under local anesthesia as per standard guidelines. Polyvinylsiloxane (PVS) impressions will be recorded in stock tray after moisture control, according to the assigned group. In experimental group, light body and putty PVS will be mixed simultaneously and placed in stock tray to record impressions in single stage. In control group, a putty PVS impression will be recorded first in stock tray and allowed to set. After setting of putty PVS, light-bodied PVS material will be applied to recorded impression surface and reseated in mouth to record final impression in second stage. All impressions will be disinfected according to the recommended guidelines. All impressions will then be assessed by a senior clinician using 3.5 x magnification loupe and graded according to the selected criteria. Impressions will then be poured in dental stone and prosthesis will be manufactured in dental lab. Participants will be recalled for prosthesis trial and fit assessment of prosthesis margins using a dental explorer instrument and visual evaluation. Proximal contact of prosthesis will be graded according the criteria and assessed using dental floss. Satisfactory prostheses will be cemented after final adjustments.

Official Title
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Clinical Evaluation of Impressions Made Using One Step & Two Step Polyvinylsiloxane Impression Techniques and Resulting Fixed Prosthesis-A Randomised Controlled Trial

Conditions
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Missing Teeth, Endodontically Treated Teeth, Discoloration, Tooth, Prosthesis Failure, Dental, Open Margin on Tooth Restoration

Intervention / Treatment
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* Device: Polyvinylsiloxane impression with different techniques


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Indication of fixed-fixed partial denture or crown Good oral hygiene Sound abutment tooth (vital/non-vital) Exclusion Criteria: Failure to provide written consent to participation in study Long span bridges (Greater than 3 units) Patients with bleeding disorders Cases indicated for resin-bonded prosthesis

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: One step polyvinylsiloxane impression technique<br>All impressions in this group will be recorded in a single stage, mixing light-bodied PVS material and putty PVS material simultaneously and recording of impression of prepared tooth | Device: Polyvinylsiloxane impression with different techniques<br>* One step impression technique will be compared with the standard two step technique<br>|
| Active Comparator: Two step polyvinylsiloxane impression technique<br>All impressions in this group will be made in two stages, recording putty PVS impression first and then reloading it with light-bodied PVS material to record final impression. | Device: Polyvinylsiloxane impression with different techniques<br>* One step impression technique will be compared with the standard two step technique<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of defects in impression recorded to fabricate dental prosthesis as assessed by impression quality assessment scale | Outcome assessment scale: 1. Perfect impression, no voids or defects; 2. Acceptable impression, minimal defects in non critical region; 3. Unacceptable impression, defects involving critical region. | 10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of prosthesis margin defects as assessed by Marginal adaptation assessment scale | Outcome assessment scale: 1. Adequate, adapted to tooth margins; 2. Inadequate, not accurately adapted to tooth margin | 14 days | 
| Incidence of prosthesis proximal contact inaccuracy as assessed by prosthesis contact assessment scale | Outcome assessment scale: 1. Acceptable, same as natural proximal contact on contralateral side; 2. Unacceptable; either tight or open proximal contact. | 14 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Polyvinylsiloxane impression, fixed prosthetics, impression techniques, single stage impression, two step putty wash impression, marginal fit, prosthesis fit, endodontically treated teeth