A novel CAD/CAM base metal compared to conventional CoCrMo alloys: an in-vitro study of the long-term metal-ceramic bond strength.

OBJECTIVES: This study examined the metal-ceramic bond strength between different ceramics and a novel CAD/CAM base metal alloy as well as conventional CoCrMo alloys.

METHODS: Three different base metal alloys were tested: a novel CAD/CAM milled and sintered alloy (MS), a. laser sintered alloy (LS), and a cast alloy (C). Specimens for the Schwickerath crack initiation test according to ISO 9693:2012 were prepared and veneered using the following veneering ceramics: i. Creation (Willy Geller), ii. VITA VM13 (VITA Zahnfabrik), and iii. Reflex (Wieland+Dental). The specimens were subsequently thermally aged (5,000 cycles, 5°C/55°C, dwell time: 20 s) and the bond strength was measured in a universal testing machine (Zwick 1445, 1 mm/min). Data were analyzed using two-way and one-way ANOVA, followed by a post hoc Scheffé test.

RESULTS: For the veneering ceramics VITA VM13 and Reflex, no impact of the used alloy on bond strength results was found (p=0.124-0.393). In contrast, the veneering ceramic Creation showed significantly higher bond strength values in combination with MS and LS than with C (p=0.001). For MS (p<0.001) and LS (p=0.001) alloys veneered with Reflex, significantly lower bond strengths were observed than for specimens veneered with Creation or VITA VM13. Within C alloy (p=0.012), significantly lower bond strengths were measured for specimens veneered with Reflex than for VITA VM13.

CONCLUSION: The novel CAD/CAM base metal alloy Ceramill Sintron showed comparable metal-ceramic bond strength compared to conventional CoCrMo alloys.