An Exploratory In Vitro Pilot Study of Connector Failure and Censored Load Tolerance in Cast and Laser Melted Cobalt Chromium Frameworks

A load ceiling can obscure manufacturing-related differences in cobalt–chromium framework testing. This exploratory in vitro pilot analyzed ten frameworks: five cast and five fabricated by selective laser melting (SLM). The documented protocol used a hemispherical indenter at 1 mm/min after a 100 N preload. Cast specimens fractured at 938.53–1134.63 N (mean 1012.47 ± 77.40 N); SLM specimens remained macroscopically intact at 4498.36–4501.34 N and were right-censored. At the common observed limit of 4498.36 N, the capped mean contrast was 3485.89 N, with a 4.44 ratio and a two-sided exact permutation p-value of 0.00794. Single-specimen deletion changed the contrast by at most 0.876%. Exact 95% failure-probability intervals were 47.8–100% for casting and 0–52.2% for SLM. Bayesian direction favored SLM across three symmetric priors, while magnitude remained prior-sensitive. With five reported displacements per workflow, terminal displacement was 1.459 ± 0.357 mm for casting and 2.048 ± 0.134 mm for SLM. The five calculated SLM terminal secants averaged 2155.16 ± 139.28 N/mm; different endpoint forces preclude a matched-force stiffness comparison. The findings support independent validation; censored outcomes, unavailable raw traces, and unknown batch structure limit population and causal interpretation.