Biomedical Engineering Reference
In-Depth Information
In recent decades, there is an advance in the study of new therapies for complete periodontal
regeneration. Regenerative procedures are forms of treatment aimed to reconstruct the lost structure
or damaged periodontal tissue. The periodontal regeneration involves a sequence of biological
events including adhesion, migration, proliferation, and differentiation
[68,69]
. Numerous methods
of therapies have been tested to achieve periodontal regeneration.
The complete regeneration of periodontal tissues has not yet been achieved, but significant
progress has been achieved through the use of autogenous bone grafts, bone allografts, guided
tissue regeneration (GTR), the implantation of alloplastic materials, and use of cellular factors.
Autogenous bone grafts are transplanted from one place to another in the same individual.
Because of their osteogenic potential, autogenous bone grafts have been widely used in periodontal
therapy. They can be from intra- or extra-oral sources. However, the necessity of a second surgical
site, which can complicate post-surgery, is a disadvantage that has been associated with their use.
Allografts are transplanted between genetically different individuals of the same species. Iliac
bone marrow, lyophilized bone graft, freeze-dried bone allograft (FDBA), and decalcified FDBA
are the types of bone allografts widely available in commercial tissue banks
[70]
. However, despite
the approval of bone tissue banks, the real osteogenic potential of these transplants is questionable.
In dentistry, GTR is often used in the reconstruction of periodontal defects. GTR technique is
based on the use of biocompatible membranes in order to prevent accelerated migration of the
epithelium to the injured site, and allows conditions for the regeneration of all periodontal attach-
ment apparatus. The use of GTR has shown favorable results on the periodontal regeneration
when applied in some specific kinds of bony defects. It is used in different types of barriers, such
as membranes, expanded polytetrafluoroethylene, collagen
[71]
, cellulose, and polylactic acid
[72
74]
.
Although polymeric products show positive results, there are still major challenges to overcome
in their use in periodontal regeneration. Research attempting to overcome these challenges include
the use of ceramic nanoparticles, and among them, bioactive glass nanoparticles incorporated into
GTR membranes are of particular interest because they induce a significant increase in cellular
uptake and cell adhesion compared with bioactive glass microscale
[75,76]
.
Alloplastic materials are synthetic, bioactive, and biocompatible, and may act as a substitute for
living tissue. Recently, bioactive materials have shown to be an excellent alternative for periodontal
structure regeneration, stimulating the infiltration of responsive cells, promoting cell differentiation,
and formation of bone tissue. Research shows that the bioactive materials are capable of stimulating
periodontal healing. Among these materials, bioactive glass has been widely researched in peri-
odontal regeneration.
As mentioned previously, bioactive glass nanoparticles have been widely studied due to its
superior bioactivity compared with conventional bioactive glasses. So this justifies the development
of new systems with bioactive glass nanoparticles that can be used in the periodontal regeneration.
Cell therapy for periodontal regeneration is a new option; studies suggest that periodontal liga-
ment consists of different cells in various stages and that these cells when necessary may differenti-
ate into cementoblasts, osteoblasts, or fibroblasts of the periodontal ligament
[77]
. The discovery of
these called progenitor cells suggests the possibility of repair of damaged periodontal tissue.
Recent studies have shown that periodontal ligament cells in direct contact with bioactive glass
nanoparticles exhibited increased proliferation and cell viability and also an increase in alkaline
phosphatase activity
[78]
(
Figure 15.7
).
