Introduction: Periodontitis is a common but easily preventable disease that affects many adults. It is characterized by a state of chronic inflammation that attacks the hostʼs gum tissue and periodontal ligaments. If severe and left untreated, periodontitis can cause tooth decay and tooth loss. Smoking is a significant risk factor because it causes an imbalance of the normal collagen type 1 metabolism that occurs via metalloproteinase actions. In particular, matrix metalloproteinase 8 (MMP-8) is a key player in this collagen degradation.

Methods: Primary human gingival fibroblasts (HGVF) isolated from patients who were identified as inflamed nonsmoker (IFN) and inflamed smoker (IFC) were cultured in serum-free media over a 72 hour period. Samples from n=6 patients reflected 83% African American, 67% female and 33% self reported smokers. We measured production of MMP-8, intact and degraded collagen type I in the secreted fraction (conditioned media) and in the incorporated extracellular matrix (ECM). In the secreted and incorporated fractions the 24hr time point was optimal for measuring collagen metabolism as detectable levels approached zero by 72 hours.

Results: HGVF isolated from smoker patients (IFC) produced more degraded collagen (400% more secreted and 25% more incorporated) than HGVF isolated from the non-smoker (IFN). In addition, MMP-8 was secreted by IFN and IFC fibroblasts in the range of 0.05ng/culture and incorporated in the range of 0.076ng/culture (IFN) and 0.014ng/culture (IFC). MMP13 was undetectable in both the secreted and incorporated fractions.

Conclusion: This data supports the hypothesis that inflamed tissue isolated from a current smoker exhibits a profile of collagen metabolism in line with more acute diseased state (fibrotic collagen profile). In addition, the culture of primary human gingival fibroblasts in serum-free medium for 24 hours is a viable method to study both the disease mechanism of periodontitis and potential therapeutics to treat the disease.