Passive Fit of CAD/CAM Screw-retained Metal Frameworks Versus Screwmented Ones

Passive Fit of CAD/CAM Implant Supported Screw-retained Metal Frameworks Based on Actual Versus Screwmented Ones Based on Virtual Implant Position: A Randomized Clinical Trial

CAD/CAM (computer aided design/ computer aided manufacturing) constructed screw retained implant supported frameworks give solutions for the problems arising from the lost wax technique by improving accuracy, adaptation and passive fit of the final restoration. However, concerns about the passive fit of a pre-implant insertion CAD/CAM constructed framework still exists due to the expected errors in imaging, registration, surgical guide construction, adaptation and hence transferring the planned position intra-orally.

9. PICO Format: Population: mandibular free end saddle requiring 2 implants. Intervention: Digitally fabricated screw-mented retained metal frameworks constructed before implant placement Control: Digitally fabricated screw retained metal frameworks constructed after implant placement Outcome: Outcome Measuring device Measuring unit Passive fit One screw test Binary 13 Screw resistance Binary Radiographic ( digital periapical radiography) Binary III. Methods A) Participants, interventions & outcomes 9. Study settings: i. The study will be conducted at Department of Oral Implantology, faculty of oral and dental medicine, Cairo University, Egypt. ii. Participants will be selected from the outpatient clinic of implantology department, faculty of oral and dental medicine, Cairo University, Egypt. 10. Eligibility criteria: A-Inclusion criteria: i- Mandibular Kenndy Class I. ii- Opposing completely dentulous, fully or partially restored dentition. iii- Good oral hygiene. iv- The patient should have bone for implants, minimum bone height 10 mm and minimum bone diameter should be 6 mm. v- Adequate inter arch space for restoration 15mm or more. vi- Adult patients age ≥18 years B- Exclusion criteria: i. any medical disorder that could complicate surgical phase or affect osteointegration. Radiation chemotherapy. ii. smokers more than 10/daily. iii. Uncooperative patients. iv. Patients with Para-functional habits v. Patients with severe periodontal diseases. vi. Patients with limited mouth opening. vii. Presence of intraoral pathological lesions. viii. Diabetic (HbA1c >7.5%).

Trial design to be conducted is RCT, split mouth , two arms, and Equivalence frame with 1:1 allocation ratio.

The study is based on different technical procedures of fabrication of the frameworks. Since these differences are visible, the operator, the assessor and the technician involved in the study cannot be blinded. Since blinding was not possible, randomization was delayed till the prosthetic phase to avoid any performance bias in the surgical steps. But the statistician will be blinded .

Intervention group in which the edentulous area will be restored with 3-implant screwmented CAD/CAM frameworks constructed based on planned implant positions.

Control group: edentulous area will be restored with 3-implant conventional screw retained CAD/CAM frameworks constructed after implant placement

Intervention group in which the edentulous area will be restored with 3-implant screwmented CAD/CAM frameworks constructed based on planned implant positions.

Control group: edentulous area will be restored with 3-implant conventional screw retained CAD/CAM frameworks constructed after implant placement.

Evaluation of Passive fit between CAD/CAM Implant Supported Screw-retained Metal Frameworks Based on Actual Versus Screwmented Ones Based on Virtual Implant Position using one screw test .

.Inclusion Criteria: Mandibular Kenndy Class I. Opposing completely dentulous, fully or partially restored dentition. Good oral hygiene. The patient should have bone for implants, minimum bone height 10 mm and minimum bone diameter should be 6 mm. Adequate inter arch space for restoration 15 mm or more. Adult patients age ≥18 years Exclusion Criteria: - . any medical disorder that could complicate surgical phase or affect osteointegration. Radiation chemotherapy. ii. smokers more than 10/daily. iii. Uncooperative patients. iv. Patients with Para-functional habits v. Patients with severe periodontal diseases. vi. Patients with limited mouth opening. vii. Presence of intraoral pathological lesions. viii. Diabetic (HbA1c >7.5%)

de Franca DG, Morais MH, das Neves FD, Barbosa GA. Influence of CAD/CAM on the fit accuracy of implant-supported zirconia and cobalt-chromium fixed dental prostheses. J Prosthet Dent. 2015 Jan;113(1):22-8. doi: 10.1016/j.prosdent.2014.07.010. Epub 2014 Sep 30.