That depends a little bit on what you mean by "serious".
Throughout postwar West German history, the interests of former Germans from those (then Eastern European) areas were represented essentially by two large organizations, one being called the Bund der Heimatvertriebenen / Entrechteten (BHE), and the Vertriebenenverbände resp. the Schlesierbund, the first being a political party which at first supported the moderate left (SPD), and later (early 1950s) switched to and joined the conservative CDU party. All of these organisations of former Sudeten and Silesian Germans attempted to keep the question alive in contemporary German politics on how to regain both property rights and a "right to their homeland" in Eastern Europe; while it is fair to point out they did not wholly demand a return of the land proper to the German nation state (some member wings only wished restitution of their properties and land, and right to live there), they were, over time, increasingly viewed as yesteryears' political movement by the wider public.
Accordingly, voting results of the BHE began decreasing as early as the late 1950s until they were wholly subsumed in West Germany's conservative party.
The Labor Party's 1972 government under Willy Brandt then signed the so-called Ostverträge (against much conservative protest), which confirmed that Germany was not seeking restitution of these lands in the sense of international law, and would also not do so in the future, and was waiving all rights and claims to them as a nation state.
By the time of German unification, yearly meetings of the Schlesierbund and the Vertriebenenverbände, while still having large memberships and media coverage especially in the German South (Bavaria) where they were particularly strong, were considered to still have a certain influence in the right wing of Germany's governing party, but not to the extent of reopening the restitution question. This was virtually guaranteed by Chancellor Helmut Kohl (a historian btw), who had learned that he would lose voters over reopening this question (he had calculated he had the Sudeten/Schlesien organizations votes either way, but would lose more centrist voters if rejecting the Ostverträge, which had gained wide public majority approval by the late 1970s).
The negotiations over German unification then further clarified that West Germany's preceding agreements (the Ostverträge) would be rolled over into United Germany's setup, thus guaranteeing that a united Germany considered the question settled in international law, and had thus no longer any legal international claims to it.
However, after various lawsuits filed by the Vertriebenenverbände in the early 1990s, the question of private property restitution of disowned former landowners in Eastern Europe remained open at least insofar as the European court of Human Rights decided in the early 2000s that nations could not waive their citizens' rights to property in treaties, which leaves the question open whether individual lawsuits can be filed for restitution of private property. (I do not know the current state of the legal cases there, and whether they have been finally settled, or whether the ECHR decided that in this particular case rights no longer applied.)
In short, and politically speaking, through out the German unification negotiation process all mainstream German parties (bar right wing extremist ones or fringe groups, some of which though were within the conservative CDU party) had rejected the irredentist notion that "Germany", by any definition, still included territories east of the Oder/Neisse line; so, "serious calls" existed, but had little public support, and virtually none higher up in government or parliament.