irst, here and everywhere Heidegger sees dialectic as a misuse of logos that tries to subordinate being to propositional thinking: Platonic dialectic, for example, is "a genuine philosophical embarrassment" (Being and Time, German p. 25; cf. 286, 300-301, 432). Secondly, according to Heidegger, truth as unconcealment is so fundamental to our condition that a sincere attempt to do away with it would amount to "suicide" (p. 229). Of course one could proceed to deconstruct the concept of suicide, but Heidegger would hardly condone such a move.
It is true that Heidegger himself tries to deconstruct many traditional conceptual structures, but he does so phenomenologically, not dialectically: that is, he makes a case that the tradition fails to describe the phenomena incisively enough, not that the traditional concepts are formally inconsistent or incomplete.