Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT02477358 |
| Other study ID # |
0443-14-FB |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
September 29, 2014 |
| Est. completion date |
June 1, 2016 |
Study information
| Verified date |
September 2023 |
| Source |
University of Nebraska |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
In cases of permanent tooth avulsion, it is widely accepted that some necrosis always occurs
after avulsion injury. If the pulp tissue does not revascularize or if endodontic therapy is
not performed, the pulp space can become infected. Platelet rich fibrin (PRF) is a second
generation platelet concentrate that allows the clinician to obtain fibrin membranes enriched
with platelets and growth factors from an anticoagulant-free blood harvest. Clinical
relevance of PRF and revascularization has been demonstrated in several case studies of
avulsion. To date no human clinical trials have been performed evaluating the effectiveness
of PRF on pulpal revascularization after reimplantation and its benefits in limiting
inflammation. The following study consists of two phases: Phase 1: An in vitro model
evaluating the effects of PRF in limiting inflammatory response of pdl cell cultures in the
presence of an inflammatory mediators. Phase 2: An in vivo model utilizing mature teeth
previously treatment planned for extraction, treating with PRF, reimplanting teeth and
following for three to four months before extracting and performing histological analysis. If
PRF is capable of promoting revascularization in mature teeth the potential benefits extend
to limiting the need for endodontic therapy following mature tooth avulsion, potential for
mature tooth transplantation in situations of congenitally missing teeth, and utilization of
PRF in endodontic revascularization therapy.
Description:
When a tooth is avulsed, it is separated from its socket causing damage to the attachment
apparatus. The periodontal ligament (pdl) is a group of specialized connective tissue fibers
that attaches the cementum of the root (outer layer) to the alveolar bone. Avulsion can cause
damage to the pdl and possible cemental tears. If the periodontal ligament is left attached
to the root and minimal time lapse occurs damage to the tissues is usually limited. In these
cases, reimplantation is a widely accepted treatment; however the long term success of an
avulsed tooth is dependent on various factors. When excessive drying occurs prior to
re-implantation, a severe inflammatory response is elicited directly on the root surface
which may result in osseous replacement or replacement resorption. Some necrosis always
occurs after avulsion injury, and while the necrotic pulp is of little consequence, this
necrotic tissue is at high risk for bacterial contamination. If the pulp tissue does not
revascularize or if endodontic therapy is not performed, the pulp space can become infected.
It has been suggested that treatment strategies should attempt to limit peri-radicular
inflammation therefore promoting favorable cemental healing and limiting unfavorable osseous
replacement.
Platelet rich fibrin (PRF) is a second generation platelet concentrate that allows the
clinician to obtain fibrin membranes enriched with platelets and growth factors from an
anticoagulant-free blood harvest and without the addition of artificial biochemical
modification. PRF has demonstrated clinical relevance through its ability to stimulate cell
proliferation of osteoblasts, gingival fibroblasts, and periodontal ligament (PDL) cells. In
addition, PRF has been shown to limit epithelial cell growth therefore promoting connective
tissue and alveolar bone regeneration and inhibiting epithelial proliferation. These
properties make it a favorable product for surgical procedures requiring micro
vascularization.
In vitro studies with PRF and canine dental pulp cells demonstrate PRF's ability to promote
chemotaxis and proliferation of the pulp cells and contributed to pulp repair. When PRF was
combined with human dental pulp cells derived from extracted third molars it did not
interfere with vitality and stimulated proliferation and differentiation. Additionally it
upregulated the expression of osteoprotegerin and alkaline phosphatase.
Animal models evaluated PRF granules combined with human pdl stem cells and placed them on
the root surface of freshly extracted canine teeth. The teeth were then reimplanted and
evaluated histologically after a healing phase. A regeneration of the PDL-like tissue and
reduction in ankylosis and inflammation were noted in animals with the PRF granules.
Clinical relevance of PRF and revascularization has been demonstrated in several case studies
of avulsion. These case studies utilized a general protocol of minimally instrumenting the
avulsed tooth. One study performed a 3 mm resection of the root apex followed by minimal
instrumentation of the canal. Blood is then drawn from the patient and PRF is prepared via
Choukroun's method. The PRF is then placed on the root surface and condensed into the canal.
The tooth was then reimplanted, splinted, and the patient followed for up to 24 months. The
tooth tested vital to thermal and percussion testing and radiographically did not show signs
of replacement resorption or inflammation.
To date no human studies have been performed evaluating the effectiveness of PRF on pulpal
revascularization after reimplantation and its benefits in limiting inflammation.
Additionally, only histological evidence of the benefits of PRF has been demonstrated in
animal models. If PRF is capable of promoting revascularization in mature teeth the potential
benefits extend to limiting the need for endodontic therapy following mature tooth avulsion,
potential for mature tooth transplantation in situations of congenitally missing teeth, and
utilization of PRF in endodontic revascularization therapy.
The following research would consist of two phases: Phase 1. An in vitro model evaluating the
effects of PRF in limiting inflammatory response of pulp and pdl cell cultures in the
presence of an inflammatory mediators. Phase 2. An in vivo model utilizing mature teeth
previously treatment planned for extraction, treating in accordance to the procedure
documented by one group, reimplanting teeth and following for three to four months before
extracting and performing histological analysis.
