Comparisons of precision of fit between cast and CNC-milled titanium implant frameworks for the edentulous mandible.
OBJECTIVE
The purpose of this study was to investigate and compare the precision of fabrication in repeatqdly produced computer numeric controlled (CNC)-milled frameworks with consventional castings, and to analyze the distortion from application of different veneering materials.


METHODS
Twenty identical titanium frameworks were fabricated by means of a CNC milling technique for the same master model. Five conventional frameworks were cast as a control group to the same model. The frames were measured with regard to fit in a coordinate measuring machine linked to a computer. Measurements were made during different stages of handling of the titanium framework, and after veneering materials had been applied.


RESULTS
The CNC frameworks showed a statistically better fit and precision of fabrication compared to conventional castings (P < .05). The application of veneering material did not statistically affect the fit of the titanium frameworks (P > .05).


CONCLUSIONS
It is possible to fabricate implant-supported frameworks by means of the present CNC technique with a very high precision and repeatability.
The Brånemark Clinic, Göteborg, Sweden.
Anders
A
Ortorp
Torsten
T
Jemt
Tomas
T
Bäck
Tord
T
Jälevik
D000180:Acrylic Resins / Q000737:chemistry; D017076:Computer-Aided Design; D000044:Dental Abutments; D003734:Dental Casting Investment / Q000737:chemistry; D003735:Dental Casting Technique; D015921:Dental Implants; D003776:Dental Porcelain / Q000737:chemistry; D019094:Dental Prosthesis, Implant-Supported; D003801:Dental Veneers; D003779:Denture Design; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation; D008334:Mandible; D015203:Reproducibility of Results; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
D000180:Acrylic Resins; D003734:Dental Casting Investment; D015921:Dental Implants; D006047:Gold Alloys; D003776:Dental Porcelain; D014025:Titanium