Accuracy of Conventional and Digital Impression Techniques Used for Maxillary Hybrid Prosthesis

Study Overview
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Brief Summary
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evaluation and comparison of the accuracy of conventional and digital impression for full arch screw retained prosthesis for edentulous maxilla.

Detailed Description
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Each patient received 6 implants in the maxillary ridge (widely distributed across the arch) in the following positions: central incisors, canines/first premolar teeth and first molar teeth aided by surgical stent. then each patient received 2 types of impression techniques Technique 1 :conventional impression conventional open tray impression technique with splinted transfers using vinylpolysiloxane and Technique2 : Digital impression taken using original scan bodies torqued to the implants .three dimensional accuracy of impression techniques was evaluated using linear measurements and 3D deviation between the two techniques was measured.

Official Title
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Accuracy of Digital and Conventional Impression Techniques for Maxillary Full Arch Screw Retained Hybrid Prosthesis

Conditions
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Prosthesis Durability

Intervention / Treatment
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* Other: impression techniques for implant used for maxillary screw retained hybrid prosthesis


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The patients were selected according to the following inclusion criteria: Completely edentulous maxillary and mandibular ridges Healthy ridge covered by normal oral mucosa and free from any ridge flabbiness. All of the patients were dissatisfied with the retention and stability of their maxillary conventional dentures and expressed a strong desire for a more stable prosthesis. Sufficient bone quantity and quality in the front and posterior maxillary regions, as determined by preoperative CBCT, to accommodate six implants with a diameter of at least 3.5 mm and a length of at least 10 mm. Enough restorative space (from the mucosa covering the crest of the maxillary residual ridge to the occlusal plane) to allow the fixed prosthesis to be constructed ,preliminary jaw relationship revealed this. It's been at least a year since the last extraction. Exclusion Criteria: Systemic diseases that may alter tissue response to implantation and affects osseointegration (radiation, diabetes, osteoporosis, bleeding disorders or hepatic patients) Long term immunosuppressive and corticosteroid drug therapy. Patient with abnormal habits as clenching and bruxism. Smoking patients. Patients with problems in TMJ. Neuromuscular diseases.

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 65 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: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: the conventional open tray splinted impression technique and the digital intraoral impression technique were done for each patient
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: technique 1: conventional splinted open tray impression<br>a conventional open tray impression technique splinted with ligature wire and duralay resin was done with polyvinyl siloxane impression . analogues were screwed to the impression copings and casts were poured. | Other: impression techniques for implant used for maxillary screw retained hybrid prosthesis<br>* conventional splinted open tray impression technique was done for maxillary implants to fabricate screw retained hybrid prosthesis and digital intra oral impression was done for the same patients after screwing scan bodies to the implants intra orally. evaluation of accuracy and 3D deviation between the two techniques was done<br>* Other names: digital and conventional impression techniques;|
| Other: technique 2: digital intraoral impression technique<br>scan bodies were screwed to implants intraorally and digital scanner was used to record digital impression, scanning protocol started from occlusal ,buccal to palatal surfaces. The resulting scans were then exported in the standard tessellation format (.STL) | Other: impression techniques for implant used for maxillary screw retained hybrid prosthesis<br>* conventional splinted open tray impression technique was done for maxillary implants to fabricate screw retained hybrid prosthesis and digital intra oral impression was done for the same patients after screwing scan bodies to the implants intra orally. evaluation of accuracy and 3D deviation between the two techniques was done<br>* Other names: digital and conventional impression techniques;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| accuracy of impression technique | deviation measurements digitally | immediately after the intervention/procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| passivity of final restoration | Clinical measurement of prosthesis passivity using single screw test of Sheffield. | immediately after the intervention/procedure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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digital impression, conventional impression