Oral tissue regeneration

Loss of oral tissues can be due to disease, trauma, therapeutic interventions, or developmental
aberrations. Standard therapeutic interventions result most frequently in a reparative type of healing,
which in turn often results in functionally and aesthetically compromised conditions. A variety of
biomaterials and approaches have been used aiming at regenerating the oral tissues, including bone
grafts/substitutes, guided tissue regeneration membranes, growth and differentiation factors, bioactive molecules, scaffolds, cells, and various combinations of these elements.

Periodontal disease, for example – an inflammatory disease of microbial aetiology – results in loss of the tissues surrounding the teeth, including bone, and in its advanced stages it leads to tooth loss as well. Greater clinical improvements and better aesthetic outcomes may be achieved with procedures aiming at regenerating the lost tissues around teeth. In addition, in cases where oral implants are planned for replacing missing teeth, regeneration of the lost or missing bone is often required. Similarly, regenerative procedures are often needed for treating peri-implant inflammatory lesions (known as peri-implantitis).

What works, and what works better?
Regenerative treatment en periodontal (a) and bone defects (b), involving implantation of bone biomaterials, may facilitate complete periodontal regeneration (c) and installation of oral implants (d).There is a constant search for the ideal biomaterial, and the ideal approach to regenerate the missing tissues. Autogenous bone (which is bone taken from the same patient) has been considered for many
years to be the “gold standard” in grafting materials. Autogenous bone harvesting is, however, associated with some drawbacks, such as additional patient suffering, surgical complications related to the donor site, and limited graft availability, as well as graft resorption. To replace or reduce the need for autogenous bone grafting and to optimize the regenerative outcome, various biomaterials and approaches have been developed.

Pioneering studies by researchers at the Department of Dentistry have led to the development of a treatment strategy for regenerating the lost tissues around periodontally compromised teeth. The technique, called Guided Tissue Regeneration (or simply the “membrane” technique), is
still applied in the clinic all over the world. Currently, focus is placed on tissue engineering approaches involving combinations of scaffolds, bioactive molecules, and cells. Issues addressed by current research include tissue-biomaterial interactions, functionalizing biomaterials for enhancing the regenerative outcome, and evaluating systemic conditions (such as diabetes and osteoporosis) that may aggravate tissue loss and/or influence the outcome of regenerative procedures. In collaboration with national and international partners, including the dental industry, studies are being performed – using a variety of in vitro and preclinical in vivo models, and also randomized clinical trials and human histological evaluations – to assess such technologies and approaches that aim at regenerating tooth and periodontal tissues, as well as bone in association with oral implant therapy.

Projects

  1. Growth and differentiation factors (GDFs). GDFs are potent regulators of many processes relevant to tissue regeneration. We perform preclinical in vivo, clinical, and human histological evaluation of such factors for orofacial tissue regeneration, including pulp, dentin, and periodontal regeneration, and for bone regeneration in association with oral implants.
  2. Bone substitute materials. Bone-derived and synthetically produced bone substitute materials are suggested, either alone or in combination with autogenous bone grafting, for eliminating or reducing, respectively, the amounts of autogenous bone needed. Such materials are constantly evaluated in preclinical in vivo experiments and clinical studies for periodontal indications and in association with oral implants.
  3. Systemic conditions and tissue regeneration. Diabetes and osteoporosis seems to compromise the outcome of bone regenerative procedures. Preclinical in vivo studies explore the influence of such systemic conditions on bone regenerative procedures and in association with oral implants.
  4. Innovative dental materials. Preclinical testing of dental materials for hard tissue regeneration in and around the tooth.
  5. Bone Tissue Engineering. We perform preclinical and clinical studies testing different scaffold materials, designs, and nano-surface topographies, various biomolecules and types of cells (for instance autogenous bone cells, mesoangioblasts, mesenchymal bonemarrow- derived cells, and dental-pulpderived cells) for their potential to enhance bone regeneration.

Milestones

Development of the guided-tissue regeneration technique for periodontal regeneration, which is applied worldwide in the clinic
(Karring T. Perio. 2000;1993,1:26–35) 

Co-editing several editions of Textbooks on Clinical Periodontology and Implant Dentistry
(Eds: Lindhe J, Karring T, Lang NP. 5th edition, Blackwell-Munksgaard, 2008)

Co-editing the only existing Textbook on Biocompatibility of Dental Materials
(Schmalz G, Arenholt-Bindslev D. 1st edition, Springer, 2008)

Peri-implantitis: pathogenesis, diagnosis, and treatment as evaluated in cynomolgus monkeys
(Schou S. Dr. odont. thesis, University of Copenhagen, 2004)

Deproteinized bovine bone in periodontology: animal experiments and clinical studies
(Stavropoulos A. Dr. odont. thesis, Aarhus University, 2010)

Methods

  • In vitro methods
    • Cell cultures; cell sorting and differentiation assays
    • Elisa; Real-time PCR
  • Preclinical in vivo evaluations in rodent, porcine, and canine platforms
  • Histology
    • Decalcified (paraffin) embedded tissues
    • Plastic non-decalcified embedded tissues, including biomaterials and/or oral implants (thin – thick sections)
  • Micro-CT scanning
  • Stereology as a method for obtaining unbiased estimates of tissue regeneration
  • Randomized controlled clinical trials.

Contacts

Rubens Spin-Neto
Assistant Professor

Email:

David Christian Evar Kraft
Associate professor

Phone: +4587168071
Email:


Henrik Løvschall
Associate professor

Phone: +4587168118
Email: