If a Motion for Class Certification is denied by the court, does the case continue?
YES Unless there is some other reason why not.
CLASS CERTIFICATION PROCEDURES ARE GOVERNED BY Rule 23(c)(1)(A) of the Federal Rules of Civil Procedure (Rule 23): “At an early practicable time after a person sues or is sued as a class representative, the court must determine by order whether to certify the action as a class action.” If the court denies certification, the action will proceed as an individual action. The court should not consider the impact of denying class certification in making its ruling 
Ruling on Certification
If the court denies certification, the action will proceed as an individual action. The court should not consider the impact of denying class certification in making its ruling.
Source, and my emphasis.
Footnotes  and  refer to Kovaleff v. Piano, 142 F.R.D. 406, 408 (S.D.N.Y.)1992 and both comment that:
... whether denial of class certification would result in the putative class never obtaining relief is irrelevant to whether the named plaintiffs meet the requirements of Rule 23.
A relevant extract from the cited case, at 408, is:
While the Court was initially concerned about the fact that denial of class action status here might well foreclose the possibility of any action being brought on behalf of the class, see Korwek v. Hunt, 827 F.2d 874 (2d Cir.1987), the Court is now convinced that that circumstance is irrelevant to whether these plaintiffs meet the requirements of Rule 23.