Radiographic inspection of porosity in pure titanium dumbbell castings.
BACKGROUND
Titanium frameworks are frequently indicated for implant supported prostheses; however, voids are usually encountered inside cast titanium.


OBJECTIVE
This study aimed to confirm the efficacy of a radiographic technique for inspection of porosity in commercially pure titanium castings with different diameter.


METHODS
Sixty dumbbell rods (n=20) with a central 1.5, 2.0 and 3.5mm diameter were prepared by lost-wax casting. Cast specimens were finished and polished and submitted to radiographic examination (90kV, 15mA, 0.6s and 10-13mm of distance) using periapical film. The radiographs were visually analysed for the presence of porosity in the extension of the dumbbell or in the central portion of the rods. Data were submitted to Pearson Chi-square test (5%).


RESULTS
The tested radiographic method proved to be suitable for the evaluation of cast frameworks. Internal porosities were observed in most of the specimens (91.7%) (p=0.0005); however, only 20% occurred on the central portion of the rods (p=0.612).


CONCLUSIONS
Internal porosities can be visualised through radiographs and occur mostly in small diameter structures. The radiographic evaluation of metal structures can improve the quality of frameworks and thereby potentially increase the longevity of the rehabilitation.
Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil. julynunez@terra.com.br
Juliana Maria Costa
JM
Nuñez
Jessica Mie Ferreira Koyama
JM
Takahashi
Guilherme Elias Pessanha
GE
Henriques
Mauro Antônio de Arruda
MA
Nóbilo
Rafael Leonardo Xediek
RL
Consani
Marcelo Ferraz
MF
Mesquita
D003734:Dental Casting Investment / Q000737:chemistry*; D003735:Dental Casting Technique; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D016062:Porosity; D016300:Radiography, Bitewing / Q000295:instrumentation; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D014962:X-Ray Film
D003734:Dental Casting Investment; D003764:Dental Materials; D014025:Titanium