Clinical trial NCT05770011: Digital Versus Conventional Impression Technique in Mandibular Arch
Official title: Accuracy of Impression Techniques and Their Effect on the Passive Fit of Screw- Retained Bar Splinting Two Interforaminal Implants
Study type: INTERVENTIONAL
Overall status: ACTIVE_NOT_RECRUITING
Phase: NA
Conditions: Edentulous Jaw
Lead sponsor: Ain Shams University
Sponsor class: OTHER
First posted: 2023-03-15
Enrollment: 54
Sex: ALL
Minimum age (years): 50
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: one control group and two comparator groups
Primary purpose: TREATMENT

Brief summary: 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.

Detailed 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.

Eligibility criteria: 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.

Primary outcomes:
measure: linear accuracy of impressions by superimposition
timeFrame: 1 year
measure: Angular accuracy of impressions by superimposition
timeFrame: 1 year
measure: passive fit of screw retained bars
timeFrame: one year
Secondary outcomes:
Other outcomes:
Locations:
city: Cairo
country: Egypt
facility: Faculty of Dentistry Ain Shams University
Study officials:
affiliation: Ain Shams University
name: Marwa El Kassaby, PhD
role: STUDY_DIRECTOR
References: