Biting Force and Chewing Efficiency of Complete Dentures.
Condition: Biting; Chewing Problem
MeSH terms: Bites and Stings
Study type: Interventional

Summary: 
      The aim of this study was to compare the MBF and chewing efficiency of complete denture bases
      fabricated by conventional, 3D printing and milling techniques. The research hypothesis was
      that, there are no signiﬁcant differences in MBF and chewing efﬁciency in complete dentures
      fabricated by the three methods.
    

Detailed description: 
      Participant selection and treatment This study will include a clinical experiment with a
      cross-over clinical trial design. For this study, 27completely edentulous participants with
      age range of 50-65 were selected from the outpatient clinic of the Removable Prosthodontic
      Department, Faculty of dentistry, Kafr Elsheikh University, Egypt. All participants had Angle
      class I jaw relation maxillomandibular relationship, normal alveolar ridge volume, no
      temporomandibular joint disorders, no heart disease, and no systemic diseases that affect the
      complete denture treatment procedures.

      To reduce the effect of order of treatment on MBF, were successively given the following
      prosthesis i) complete dentures fabricated by the conventional technique ii) 3D printed
      complete dentures iii) milled complete dentures in a random order.

      Construction of the CADCAM 3D printed denture The same steps of the conventional technique
      will be performed till the adjustment of occlusion rims then in the dental laboratory, the
      maxillary and mandibular definitive casts and the occlusal rims will be prepared for scanning
      with scan spray. Scanning will be performed with an optical 3D scanner . The files from the
      laser-scan will be translated into stereolithography (STL) files and the CDs are virtually
      designed in ExoCad software. After minor modifications in the positions of teeth were made,
      fabrication of the dentures will be approved and the digital denture base will be fabricated
      using 3D printing technique from Dental Pink resin

      Construction of the CAD/CAM milled denture Once the complete denture has been virtually
      designed in CAD software (ExoCad software) a preview will be sent for evaluation using 3D
      viewing software. After minor modifications in the positions of teeth were made, fabrication
      of the dentures will be approved. The digital denture will be fabricated by the command
      software of the milling machine (ExoCad 5x milling machine) from prepolymerized resin acrylic
      pucks and the teeth (TSM Acetal Dental) were milled into template .After that the denture
      will be finished and polished according to the traditional procedures For all groups, after
      placement, clinical evaluations of the fit, retention, stability, occlusal relationship,
      esthetics, and phonetics were performed. Assessment of the occlusion was made with
      articulating paper, chairside adjustments were made and premature contacts were corrected.
      The patient was given a proper program for denture insertion and oral hygiene measures.

      Assessment of biting force

        -  This will be made by using a custom-made device composed of Flexiforce A 301® force
           sensor and Arduino microcontroller with a crystal display. The sensor is calibrated by
           known weight object for several times, and the sensor is covered by 3 mm layer of putty
           rubber base material.

        -  Readings will be performed at 1 week, 1 month and 3 months follow-up periods. Assessment
           of chewing efficiency The chewing efﬁciency will be evaluated according to the procedure
           described by Schimmel et al. (2007) using a chewing gum. Specimens will be prepared from
           two colored gums one with the ﬂavor "Sour Berry" (white color) and the other with the
           ﬂavor "Fancy Fruit" (orange color). Two strips of a standard size (30 9 18 9 3 mm) will
           be cut from each gum and manually stuck together. Patients will be instructed to chew
           ﬁve samples of gum on their preferred chewing side for 5, 10, 20, 30 and 50 cycles,
           respectively. Between the different tests, an interval of at least 1 min will be imposed
           to reduce the effect of fatigue. The total duration of the experiments was approximately
           8 min.

      After chewing, the samples will be then spat into transparent plastic bags, which The samples
      will be then scanned from both sides with a of resolution 500 dots per inch. The numbers of
      selected pixels will be recorded from the histogram for each side, and mean of those ﬁgures
      will be calculated. To assess the reproducibility of chewing, the subjects will be available
      to repeat the experiments on a different day.
    

Intervention name(s): conventional complete denture; CADCAM 3D printed denture; CAD/CAM milled denture
Intervention type(s): Other; Other; Other
Intervention description(s): the complete denture constructed by packing technique; The files from the laser-scan will be translated into stereolithography (STL) files and the CDs are virtually designed in ExoCad software; Once the complete denture has been virtually designed in CAD software (ExoCad software) a preview will be sent for evaluation using 3D viewing software
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: To reduce the effect of order of treatment on MBF, were successively given the following prosthesis i) complete dentures fabricated by the conventional technique ii) 3D printed complete dentures iii) milled complete dentures in a random order.
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: complete denture; Biting force; chewing efficiency; CAD/CAM