A Photoacoustic-Fluorescent Imaging Probe for Proteolytic Gingipains Expressed by Porphyromonas gingivalis.

Porphyromonas gingivalis is a keystone pathogen in periodontal disease. We herein report a dual-modal fluorescent and photoacoustic imaging probe for the detection of gingipain proteases secreted by P. gingivalis. Upon proteolytic cleavage by Arg-specific gingipain (RgpB), five-fold photoacoustic enhancement and >100-fold fluorescence activation was measured with detection limits of 1.1 nM RgpB and 5.0E4 CFU mL-1 bacteria in vitro. RgpB activity was imaged in porcine jaws with low-nanomolar sensitivity. Diagnostic efficacy was evaluated in gingival crevicular fluid samples from subjects with and without periodontal disease, wherein activation was correlated to qPCR-based detection of P. gingivalis (Pearson's r=0.71). Finally, photoacoustic imaging of RgpB-cleaved probe was achieved in murine brains ex vivo, with relevance and potential utility for disease models of general infection by P. gingivalis, motivated by the recent biological link between gingipain and Alzheimer's disease.

Vestibular tunnel approach in restoring non-carious cervical lesion gingival recessions with combination of bioceramics and collagen matrix: A case report with a 1-year follow-up.

INTRODUCTION: Non-carious cervical lesions (NCCLs) can compromise the integrity to both hard and soft tissues of teeth. This case report introduces a novel interdisciplinary technique by utilizing bioceramics-based cement (BBC) and porcine collagen matrix (CM) to reconstruct the dentogingival complex where enamel, dentin, and soft tissues were involved. CASE PRESENTATION: A 38-year-old healthy male was referred to the periodontics department for gingival recessions teeth #27-29 and a deep (NCCL) on the facial (F) #28 involving the loss of the cementoenamel junction (CEJ). The F #28 was restored with BBC according to manufacturing instructions. Soft tissues of #27-29 were simultaneously augmented with two CM strips via a coronally advanced tunnel utilizing suspended sutures. At the 6-month follow-up, approximately 100% root coverages were obtained for #27 and 29. The F #28 gingival tissue stabilized at the anticipated level of maximum root coverage (MRC), 1 mm apical to the coronally displaced CEJ. The exposed layer of BBC, F #28, was veneered with resin-modified glass ionomer to re-establish the original position of the CEJ. At the one-year follow-up visit root coverage for #28 remained stable and probing depths remained unchanged at 2 mm F #27-29. A sectional cone beam computed tomography scan illustrated the BBC restoration remained intact and well adapted. CONCLUSION: The 12-month follow-up illustrated that the BBC may be a viable restorable material while performing simultaneous gingival grafting with CM in deep NCCLs with gingival recessions. KEY POINTS: Why is this case new information? A novel approach treating the deep non-carious cervical lesion with BBC and CM. What are the keys to successful management of this case? The BBC placement needs to be flat. Secure the surgical site with non-resorbable suspensory sutures fixed by flowable composite. What are the primary limitations to success in this case? The primary limitation to success is the blood moisture control which may limit the placement of collagen matrix strips via the portal entry.