Hiroshi Shimizu, DDS, PhD,(a) Fumitake Tsue, DDS,(a) Motofumi Obukuro, DDS,(a) Hirofumi Kido, DDS, PhD,(b) Yutaka Takahashi, DDS, PhD,(a) and Hiroyuki Ohmura, DT(c)
(a)Division of Removable Prosthodontics, Department of Oral Rehabilitation, (b)Division of Oral Implantology, Department of Oral Rehabilitation, Fukuoka Dental College, Fukuoka, Japan, and (c)Fukuoka Branch Office, Dental Laboratory Aishi, Fukuoka, Japan
Purpose: The purpose of the present study was to evaluate the fracture strength of a metal-based complete maxillary denture with a newly designed metal framework that did not extend to the residual ridge crest.
Materials and Methods: Metal-based complete maxillary dentures with a conventionally designed metal framework (group A) and those with a newly designed metal framework (group B) were cast in cobalt-chromium alloy. Resin-based complete maxillary dentures (group C) were also fabricated as a control. The maximum fracture strengths were measured using a universal testing machine at a crosshead speed of 5.0 mm/minute. The differences in the mean values were compared by means of one-way ANOVA and the Student-Newman-Keuls post-hoc comparison test.
Results: The fracture strength of group A (2.01 kN) was significantly higher than that of group B (1.49 kN) (p<0.05). The fracture strength of group B was significantly higher than that of group C (0.79 kN) (p<0.05).
Conclusion: The fracture strength of the metal-based complete maxillary denture with a newly designed metal framework that did not extend to the residual ridge crest was approximately two times greater than that of the resin-based denture, but its strength was lower than the strength of the conventional denture. (Int Chin J Dent 2005; 5: 35-38.)
Clinical Significance: The metal-based complete maxillary denture with a newly designed metal framework can be used as an alternative to a conventional metal-based complete maxillary denture.
Key Words: cobalt-chromium alloy, fracture strength, metal-based complete maxillary denture, metal framework, type of failure.