Matrix metalloproteinase (MMP)-8 is a major destructive collagenase involved in periodontitis and can be regarded as a periodontitis biomarker. A neutrophil collagenase 2 (active MMP-8 [aMMP-8]) oral fluid immunoassay has recently been demonstrated to be a periodontitis risk indicator among adults. The aim of this study is to investigate whether a point-of-care mouthrinse test based on an aMMP-8 immunoassay could identify patients with oral inflammatory burden (periodontitis and caries) among adolescents with early pathologic findings.