The first “Straumann-botiss YoungProAward in Regenerative Dentistry” was presented on 4 December 2015 to Andreas Pabst, at the botiss bone & tissue days event in Salzburg, Austria. The award was presented by Dr Drazen Tadic, Managing Partner of botiss biomaterials and Dr Dirk Probst, Head of Biomaterials Product Management at Straumann.
About the winner: Andreas Pabst DMD is a resident in Oral- and Maxillofacial surgery at the Federal Armed Forces hospital in Koblenz, Germany. He holds a degree in dentistry and one in medicine from the University Medical Center Mainz, where he is currently a researcher and doctoral student. Curriculum vitae
About the botiss bone & tissue days: Several botiss bone & tissue days events are held each year in Europe and Asia attracting leading scientists and practitioners in the field of periodontology and implantology. The events are a popular educational platform for sharing and exploring the latest techniques. boneandtissue.com
The winning entry and its clinical relevance
Entitled “In-vitro and in-vivo characterization of biocompatibility and biomechanical properties of a new acellular collagen matrix (mucoderm®)”, Dr Pabst’s winning entry concerns research into the use of tissue-graft products for regenerating gum tissues. Soft tissue augmentation is still one of the main challenges in implant and periodontal therapy. While autografts (i.e. grafts from the patient’s own tissue) are used successfully, the procedure causes significant discomfort and inconvenience for the patient including pain and swelling. It may fail because of inflammation or other complications and is not always possible. A promising alternative is offered by mucoderm, which is a purified natural collagen-elastin matrix, suitable for a diverse range of soft-tissue grafting indications. Dr Pabst’s work included a series of tests that demonstrated biocompatibility of the graft material and revascularization of the tissue, with no cytotoxic or inflammatory reactions. He also examined the biomechanics and re-hydration of mucoderm, which is supplied in a dry state. His work and results give clear insights into the clinical application of the material and were commended by the jury for their clinical implications and relevance.
Problem: Since acellular collagen matrices (ACM) are made by xenogeneic sources, it is indispensable to prevent for adverse side effects and to ensure a sufficient revascularization and tissue remodeling without inflammation. Another important aspect for the clinician is to get optimal handling and biomechanical properties of the ACMs following rehydration, which restores the collagen structure lost by the freeze-drying process. Objectives: A new ACM (mucoderm®, botiss) was introduced as an innovative, three-dimensional scaffold for gingival augmentation procedures. This ACM provides an alternative to autogenous soft tissue grafts in periodontal surgery to augment keratinized tissue, to cover gingival recessions and to optimize peri-implant tissue architecture. The clinical success of such ACMs is largely dependent upon two factors: a high biocompatibility and optimal biomechanical properties. Materials & Methodology: We investigated the influence of mucoderm® matrix on viability, morphology and cytotoxicity of different oral cell lines for tissue regeneration (keratinocytes, fibroblasts, osteoblasts) as well as on progenitor and mature endothelial cells concerning the aspect of angiogenesis. These in-vitro assays were completed by a murine in-vivo model, observing the revascularization and soft tissue reaction. In order to get detailed information about the three-dimensional architecture of mucoderm® matrix, we used scanning electron microscopy (SEM) and μCT scans, complemented by synchrotron X-ray tomografic microscopy (SRXTM) at the Swiss-Light-Source (SLS). Biomechanical properties of mucoderm® matrix after different rehydration periods in different rehydration media were determined by means of tensile testing and further characterized by using Fourier-transforminfrared-spectroscopy (FTIR) and Differential-scanning-calorimetry (DSC). Results: We demonstrated a high biocompatibility and sufficient revascularization and tissue regeneration without any cytotoxic or inflammatory reactions of mucoderm® matrix in-vitro and in-vivo. SEM, μCT and SRXTM visualization displayed the external and internal architecture of the matrix in high detail, which is overall favorable to allow soft tissue and microvessel ingrowth. Concerning the biomechanics, our findings provide evidence that the initial biomechanical properties of mucoderm® matrix are significantly influenced by rehydration. Rehydration periods of 10-20 minutes in saline solution resulted in optimal mechanical and clinical behaviour. Further, there was a clear trend toward increased biomechanical properties following rehydration in blood compared to rehydration in saline solution. FTIR analysis confirmed the recovery of the graft protein backbone with increased rehydration periods. DSC measurements revealed that tissue hydration decreased thermal stability. Conclusion: Since ACMs represent completely acellular and avascular xenografts, we plan to combine mucoderm® matrix with enamel-matrix-protein (Emdogain®, Straumann), which might additional accelerate revascularization and tissue regeneration.
Impressions from the botiss bone + tissue days 2015 in Salzburg, Austria: