Faculty Bibliography

The serum protein, alpha 1-proteinase inhibitor (alpha 1-PI), defends the host against serine proteinases, e.g. PMN elastase. Using a rabbit anti-serum against human alpha 1-PI, this protein in GCF was quantified from a standard curve constructed from dot-blot analysis and characterized by Western blot. GCF was collected on filter paper strips from healthy (H), gingivitis (G) and adult periodontitis (AP) patients, then extracted with Tris/NaCl/CaCl2 buffer, pH 7.6. alpha 1-PI concentration increased with G and was highest in AP subjects. H sites only showed intact alpha 1-PI (52 kDa); no degradation fragments (48 kDa) were detected. In G and AP subjects, alpha 1-PI degradation fragments were seen in 17% and 71% of GCF samples, respectively. Both collagenase and alpha 1-PI-degrading activities in GCF increased with severity of inflammation (GCF flow). Moreover, the alpha 1-PI degrading (or serpinolytic) activity was characterized as a matrix metalloproteinase, probably collagenase, based on its in vitro response to a panel of different proteinase inhibitors including doxycycline. We propose: (1) that collagenase promotes periodontal breakdown not only by degrading collagen, but also by depleting alpha 1-PI regulation of elastase and other serine-proteinases, thereby favoring a broader attack on extracellular matrix (ECM) constituents, and (2) based on a recent longitudinal double-blind study using the techniques described above for alpha 1-PI analysis, that low-dose doxycycline administration to humans with adult periodontitis can inhibit this broad cascade of ECM degradation

Intraoral lidocaine patches have recently been approved by the US Food and Drug Administration for the production of topical anesthesia before superficial dental procedures and for the reduction of pain associated with local anesthetic injections. The results of this 5-center clinical study showed that lidocaine patches were significantly more efficacious than matching placebo patches in reducing the pain associated with 25-gauge needle insertions to the level of bone in the maxillary premolar region. Anesthetic onset occurred within 5 minutes and was present for the entire 15-minute period that the patches were in contact with the oral mucosa. In addition, the patches were safe and well tolerated by study participants. Other potential clinical applications of this novel delivery system are also discussed in this article