PEEK Versus Metallic Framework for Extra Coronal Attachment
Condition: Removable Partial Denture
Study type: Interventional

Summary: 
      Purpose: The present study was aimed to evaluate the bone height changes around abutments
      with two different framework materials for extracoronal attachment mandibular bilateral
      distally extension removable partial denture (RPD) and compare patient satisfaction
      associated with its use.

      Materials and methods:

      Ten partially edentulous patients (long span kennedy class I) were selected, for all patients
      splinting of remaining abutment were done by porcelain fused to metal bridges, after
      cementation the RPD frameworks were digitally designed by CAD software and printed into 3-D
      resin pattern after intra-oral try in of these patterns, the patients were divided into two
      equalized groups, the patients in first group received extracoronal attachment (RPD)with from
      milled PEEK (Juvora) framework. While patients in second group received extracoronal
      attachment (RPD) with conventional metal framework by lost wax technique. Digital radiography
      was used for bone height assessment of distal abutment at time of prosthesis insertion, 6 and
      12 months later. Patient satisfaction was measured using VAS scale.
    

Detailed description: 
      I-Patient selection For this study, ten patients (50-60) with mean age 55 years will be
      selected from out clinic patients Prosthodontic Department, Faculty of Dentistry, Kafr
      El_Sheikh University. The patients will have the following inclusion criteria:- Completely
      edentulous maxillary arch against partially edentulous mandible with only remaining
      mandibular anterior teeth. The selected patients will be free from any systemic diseases, the
      patients have Angle class I maxillomandibular skeletal relation, the distal extension ridge
      will be well formed and covered by healthy, firm mucosa, Good abutments with healthy
      periodontal ligament and suitable crown/root ratio (CRR) as verified by periapical
      radiograph.

      The exclusion criteria to the patients were:

      Patients with any systemic disease that could affect the rate of bone resorption which
      verified by obtaining a medical history, Patients with Para-functional habits (Bruxism and
      clenching), Patients with any septic foci or impacted teeth as verified by panoramic
      radiograph, Patients with tilted or rotated abutments. Patients with soft tissue undercuts
      involved in the design.

      For every patient the following procedures were done:

        1. Diagnostic Digital panoramic X-ray will be done, then Diagnostic Long Cone standard
           Digital peri-apical radiographs for canines will be taken to determine crown /root
           ratio.

        2. Scaling and/or root planning for remaining mandibular anterior teeth will be carried
           out, follow up of good oral hygiene measures before start of treatment plan for one
           month

        3. Correction of irregular occlusal plane will be done either by enameloplasty for
           overerupted teeth or restoration by adding composite for infraerupted one if needed.

        4. All selected patients in this study will be informed about all procedures that will be
           done and the need for regular and frequent recalls. All patients will sign the consent
           form of ethical committee in Faculty of dentistry, Kafr El_Sheikh university.

      II. Prosthetic procedures:

      For each patient, the definitive mandibular extra coronal attachment removable partial
      denture will be designed using CAD/CAM technology

      -Scanning the Master Model The mandibular master cast with porcelain crowns will be then
      fixed on the scanner table and scanned using the 3D scanner to obtain the standard
      triangulation file (STL) format.

      (Master cast) will be fixed on the table of 3 Shape scanning machine dental system, after
      application of scan-able spray (Telescan Spray zur vorbereitong von oberflacohen .Teleskop
      kronen) over the stone teeth and porcelain crowns of master model.

        -  Digital process and CAD Design of Removable Partial Denture Frameworks Secondary
           surveying of the virtual master cast will be performed digitally according to the
           predetermined path of insertion which will be used

        -  STL file of the virtual framework will be used to print the resin pattern using 3D
           printer which checked on the master cast before intraoral try in. (A tentative resin
           frameworks will be constructed by utilizing rapid prototyping technique to examine the
           accuracy of the framework)

        -  Intraoral try in will be done to verify all the framework components and determine any
           needed corrections that would be done on the STL file.

        -  Framework construction:

      According to the framework material and technique of construction, the patients will be
      equally divided in to two groups as the following:

      Group A: Patients will receive RPD frameworks fabricated from PEEK material using milling
      machine (CAD/CAM technology).

      Group B: Patients will receive RPD frameworks fabricated from Co-Cr material using casting
      machine.

      For group (A) PEEK RPD framework construction will be done as follow:

      The virtual 3D framework (STL) file will be sent to the milling machine to begin the milling
      process of PEEK discs to produce mandibular attachment removable partial denture PEEK
      framework.

      The PEEK framework will be then finished and polished then reseated on the master cast to
      check its fitting. After that, the PEEK framework will be tried in the patient mouth to check
      its fitting.

      For group (B) metallic RPD framework construction was done as follow:

      The virtual 3D framework (STL) file with supporting bars and sprues will be printed with
      resin and then invested, burnt out, and casted with chromium cobalt alloy to produce
      mandibular attachment removable partial denture metallic framework.

      The metallic RPD framework will be then finished, polished and reseated on the master cast to
      check its adaptation. After that, the metallic framework will be tried in the patient mouth
      to check its fitting.

      For each patient the in the two groups:

        1. Maxillary auto polymerized resin special tray will be constructed.

        2. Altered cast impression technique will be made Record blocks were constructed on
           maxillary secondary cast and mandibular framework on the altered master cast.

        3. After registration of the jaw relation, the casts will be mounted on semi-adjustable
           articulator using maxillary face bow for mounting maxillary cast and centric
           inter-occlusal record for mandibular one.

        4. Semi-anatomic maxillary posterior teeth will be arranged against flat mandibular teeth
           to achieve balanced lingualized occlusion.

        5. After try-in in the patient mouth, the denture will be processed and the occlusion was
           refined.

        6. Matrix inserting instrument will be used to insert and push the matrix with desired
           friction in its place (green plastic matrix for light snap in friction was the selected
           matrix), and functional pick up will be done during cementaion of crowns by applying
           finger pressure during setting of cement with proper orientation provided by the two
           temporary indirect retainers.

        7. All crowns will be cemented by resin luting cement during insertion of the extracoronal
           precision attachment removable partial denture.

        8. Periapical radiographs of abutment teeth and implant will be taken and digital panoramic
           radiographs will be made at the time of insertion and after 6 and 12 months later
    

Intervention name(s): RPD frameworks fabricated from PEEK material
Intervention type(s): Other
Intervention description(s): extracoronal precision attachment RPD frameworks fabricated from PEEK material using milling machine (CAD/CAM technology)
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Investigator)
Primary purpose: Treatment
Keywords: Framework materials; Removable partial denture; Patient satisfaction; PEEK; Bone changes