Digital Versus Conventional Impression Technique in Mandibular Arch

Ain Shams University

Status: Active, not recruiting

Conditions: Edentulous Jaw

Treatments: Device: intraoral scanner of splinted scan bodies; Device: impression material; Device: intraoral scanner of nonsplinted scan bodies

Study type: Interventional

Funder types: Other

Identifiers

NCT05770011

2351992

Details and patient eligibility

About

Objectives: Passive fit of screw retained frameworks is essential to avoid biological and mechanical failures in addition to transmission of unfavourable stresses to the bone-implant interface. However, Several factors contribute to the passive fit of screw retained prosthesis such as relative parallelism between the implants, implant number, impression material, impression technique and method of prothesis fabrication. The current study aims to evaluate the accuracy of three different impression techniques on the fit of screw retained bar splinting two inter-foraminal implants.

Methods: The study presents evaluation of the passive fit of screw retained bar fabricated with three different impression techniques.

Full description

Surgical guide will be designed for completely edentulous patients. It will be inserted into the patient's mouth, stabilized against the upper denture and secured in place. dental implants will then be placed.

For bar fabrication using the first impression technique, closed-top primary impressions will be made followed by open top secondary impression. Extraoral scanning of the impression will be done followed by digital fabrication of the bar.

For bar fabrication using the second impression technique, scanning of the lower arch will be done using Omnicam intraoral scanner. Scanning will be done by a single calibrated operator who is trained on intraoral scanning techniques.

Scan bodies will be then screwed to the implants and scanning will be done. Both scans will be previewed on the computer desktop and superimposed together. A Standard tessellation language file will be then exported, downloaded and previewed in Inlab Exocad software .Implant system and the bar design will be selected from the software library. Then, the Standard tessellation Language file will be exported to the milling machine and milling of Cobalt chromium bar will be done.

For bar fabrication using the third technique, splinting of scan bodies will be done followed by intraoral scanning of the lower arch.

Enrollment: 54 patients

Sex: All

Ages: 50 to 65 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• • Patients' age range from 50 to 65 years old.
• Good oral hygiene is mandatory.
• Sufficient restorative space (15mm) to accept implant supported over denture diagnosed by mounting the diagnostic casts.
• Firm and healthy mucosa covering the alveolar ridge.
• Minimum bone width 5.5 mm buccolingually and of 12 mm bone height as diagnosed from the pre-operative cone beam computed tomography scan.

Exclusion criteria

• Heavy smokers.
• Patients with para functional habits.
• Tempromandibular Joint Disorders. (TMJ disorders)
• Patients with systemic disorders that may affect the results of this study.
• V-shaped dental arch.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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54 participants in 3 patient groups

Conventional impression

Active Comparator group

Description:

Impression will be taken conventionally using rubber base open tray

Treatment:

Device: impression material

digital impression without splinting the scan bodies

Experimental group

Description:

Impression will be taken by intraoral scaner

Treatment:

Device: intraoral scanner of nonsplinted scan bodies

digital impression with splinting the scan bodies

Experimental group

Description:

Impression will be taken by intraoral scaner

Treatment:

Device: intraoral scanner of splinted scan bodies