Laser Assembled and CAD/CAM Prosthetic Frameworks for the Debilitated Mandible Robert Schneider, DDS, MS
University of Iowa Hospitals and Clinics Hospital Dentistry Institute Division of Maxillofacial Prosthodontics
Tradition Master cast impression Waxing Casting Cutting? Soldering? Processing/veneer material application Optimal accuracy for passive fit?
Newer Alternatives CAD/CAM Cagenix/others Optical Impression? New materials zircon/titanium/combinations? Pre-formed components of titanium joined by laser welding Computer wax/acrylic modeling and prototyping (Cynovad and others)
Why Laser Welding and CAD/CAM? Accuracy/Fit Strength Biocompatibility Cost vs. current gold $$$ Availability of pre-fabricated components Speed of fabrication Applications in both fixed and removable
Advantages to Patient Relative ease of fabrication in the laboratory Predictability Fracture/wear resistance Biocompatible Easier to achieve a passive fit
So Where Does the Team Approach Come In? Always at the initial appointment! The restorative doctor and technician should be communicating from the initial patient appointment
Journal of Dental Technology February 2009
UK Dental Laboratory Journal March 2009
JERD 21(4);215-226, August 2009
Communicate About What? What does the patient want? What can you do clinically? Implant retained or implant supported? What can you do in the laboratory? What are your limitations/comfort zone? Mounted diagnostic casts. Digital photographs. Extensive knowledge of the implant system utilized. Occlusion considerations?
32 YO Female Aggressive central giant cell tumor of the anterior mandible, resection, hip graft, restored with 4 implants and hybrid fixed restoration, titanium/laser welded substructure
Surgeon: Kirk Fridrich
Prosthesis Fabrication Danny Roberts, CDT Hawkeye Dental Studio
78 YO Male w/ Rim Mandibular Resection Due to SCCa Restored with Ti laser welded bar including Hader and Locator attachments.
Danny Roberts, CDT Hawkeye Dental Studio
68 YO Male SCCa of right mandible with resection and reconstruction with fibula graft, dental implants and Ti laser welded fixed prosthesis
Danny Roberts, CDT Hawkeye Dental Studio After market Ti components
AFTER BEFORE
74 YO Male SCCa of right mandible with resection and reconstruction with scapula graft, pectoralis free flap, dental implants and Ti CAD/CAM Hader bar and mandibular overdenture Bar scanned, designed and milled by Cagenix, Memphis, TN
Standard healing cap and custom fabricated healing cap
15 mm Custom healing cap fabricated with a provisional coping and tooth colored VLC material Etkon custom scanned/ milled titanium healing cap with scanning replica 10 mm
The Etkon scanned titanium cylinder can be utilized as a healing cap and also as a milling abutment for laser welding and framework fabrication. The cylinders can be milled in most any length desired up to 18 mm in height and various wall thicknesses
Initial placement Verification index
Cagenix, Inc Memphis, TN cloud map of proposed CAD/CAM bar design in relationship to the tooth position.
Modification proposal to increase connector dimension cloud map minus tooth position Note connector dimension
Ti Laser Welded Utilizing Custom Abutments CAD/CAM
Danny Roberts, CDT Hawkeye Dental Lab
DELIVERY
ID: 36 yo Female CC: I am here for my jaw surgery. HPI: has been under long term care with UIHC OMFS and OTO. Previous diagnosis of Chronic Multifocal Osteomyelitis associated with thyroid follicular adenoma. PMH: CRMO (Chronic Recurrent Multifocal Osteomyelitis) PSH: 1. Recurrent multifocal osteomyelitis status-post hemimandibulectomy with right fibula free-flap construction, ORIF. 2. Hemithyroidectomy for follicular adenoma on April 17, 2008. 3. Bilateral myringotomy tubes, 11/2007 4. Dental implants to fibula graft.
Diagnosis: s/p Mandibulectomy, Fibula flap reconstruction Minimal mandible labial vestibule Treatment Plan: 1. Vestibuloplasty of mandible labial 2. Partial thickness skin harvest from left thigh 3. Intraoperative Impression/border mold/ stent per Dr. Schneider 4. Possible debulking of soft tissue s/p fibula flap remaining per OTO
DIAGNOSTIC MOUNTING AND WAX UP
TRY IN OF WAX UP
DUPLICATE WAX UP FOR SURGICAL GUIDE
IMPLANT PLACEMENT
Vestibuloplasty and skin graft
Intra op splint fabrication with VLC material
VLC stent in place
Cover caps in place on Vario-Multi abutments 7 mm healing caps 3 weeks PO
Modified impression copings for Multi Fabrication of verification index on master cast Rigid index with VLC material
Location of Implants Relative to Proposed Dentition Implants were positioned anterior to the proposed dentition by as much as 9-10 mm
Bar Design Relative to Diagnostic Wax Up Cagenix, Inc. Memphis, TN
Bar Design Relative to Master Cast
Final Bar Design
Final Bar Design Compensates for implant position Significant strength, precision/passive fit New fixed acrylic resin support design with appropriate finish lines
Final Milled Framework Ti6Al4V alloy milled following verification of fit on the master cast of solid aluminum prototype
Danny Roberts, CDT Hawkeye Dental Studio
BEFORE AFTER
BEFORE AFTER
DELI VERY
42 YO Male SCCa of left BOT, hemiglossectomy, radial forearm flap, XRT, HBO. Mandibular J fixed prosthesis and maxillary palatal augmentation complete denture prosthesis. Bar scanned, designed and milled by Cagenix Inc., Memphis, TN
VERIFICATION INDEX
Danny Roberts, CDT Hawkeye Dental Studio
DELIVERY ONE WEEK POST DELIVERY
DELIVERY
So now that you are thoroughly confused, when do you laser weld or use CAD/CAM? Here are a few thoughts on both issues
LASER WELDING With accurate master cast a well fitting framework More easily able to compensate for atypical tooth placement/framework support Pre-made component assembly Strong framework Cost effective Superior to waxing/casting
CAD/CAM With accurate master cast a well fitting framework Very strong UNI framework Communication with design/milling company Able to compensate for tooth/material support? Knowledge of what we want dentally? Appropriate gingival contours?
Rounded gingival contours Rounded edges Definite finish lines Custom support for materials/teeth Very adequate retention for acrylic resin Customization done via e-mail Design verified before milling Aluminum blank milled before final frame Ti alloy stronger than CP Ti Flat gingival contour Square edges Finish lines Support for materials/teeth Adequate retention for acrylic resin
Special thanks to Danny Roberts, CDT, Cagenix Inc. and of course my wife