Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2018-10-24, 06:06:13 | version 1.58.2
39Dental Tribune Middle East & Africa Edition | May - June 2014 implant tribune < Page 38 of discomfort either intra or post-operatively (Figs. 4a & b). Bone reconstruction is a chal- lenge in dentistry (also in or- thopaedics and oncology) be- cause rebuilding bony defects caused by trauma, infections, tumours or dental extractions requires bone grafting. The lack of bone in the jaws may impede the placement of den- tal implants, thus adversely af- fecting patients’ quality of life. In order to remedy bone scar- city, a bone graft is convention- ally harvested from the chin region or the angle of the man- dible. If the amount required is too large, bone from the skull, legs or pelvis may be used. Un- like the process for harvest- ing bone marrow, the process involved in obtaining larger Fig. 11a: Bone marrow. Fig. 11g: The pellet containing the bone marrow mononuclear cells after the second centrifuge spin. Fig. 11b: Bone marrow transfer into a conic tube in a sterile envi- ronment (laminar flow). Fig. 11h: A bovine bone graft com- bined with a bone marrow stem cell concentrate. Fig. 11c: Bone marrow homogeni- sation in a buffer solution (laminar flow). Fig. 11d: Bone marrow combined with Ficoll (to aid cell separation). Fig. 11e: Pipette collection of the interface containing the mono- nuclear cells (where the stem cells are present). Fig. 11f: Second centrifuge spin. bone grafts is often associated with high levels of discomfort and, occasionally, inevitable post-operative sequelae (Figs. 5a–e). The problems related to bone grafting have encouraged the use of bone substitutes (syn- thetic materials and bone from human or bovine do- nors, for example). However, such materials show inferior results compared with autolo- gous bone grafts (from the patient himself/herself), since they lack autologous proteins. Therefore, in critical bony de- fects, that is, those requiring specific therapy to recover their original contour, a novel concept to avoid autologous grafting, involving the use of bone-sparing material com- bined with stem cells from the same patient, has been gain- ing ground as a more modern philosophy of treatment. Con- sequently, to the detriment of traditional bone grafting (with all its inherent problems), this novel method of combining stem cells with mineralised materials uses a viable graft with cells from the patient himself/herself without the need for surgical bone harvest- ing. Until recently, no studies had compared the different meth- ods available for using bone marrow stem cells for bone reconstruction. In the follow- ing paragraphs, I shall sum- marise a study conducted by our research team, which en- tailed the creation of critical bony defects in rabbits and subsequently applying each of the four main stem cell meth- ods used globally in order to compare their effectiveness in terms of bone healing:[1] • fresh bone marrow (with- out any kind of process- ing); • a bone marrow stem cell concentrate; • a bone marrow stem cell culture; and • a fat stem cell culture (Figs. 6 & 7). In a fifth group of animals, no cell therapy method (control group) was used. The best bone regeneration results were found in the groups in which a bone marrow stem cell concentrate and a bone marrow stem cell culture were used, and the control group showed the worst results. Con- sequently, it was suggested that stem cells from bone mar- row would be more suitable than those from fat tissue for bone reconstruction and that a simple stem cell concentrate method (which takes a few hours) would achieve similar results to those obtained using complex cell culture proce- dures (which take on average three to four weeks; Figs. 8a & b). Similar studies performed in humans have corroborated the finding that bone mar- row stem cells improve the repair of bony defects caused by trauma, dental extractions or tumours. The histological images below illustrate the po- tential of bone-sparing materi- als combined with stem cells for bone reconstruction (Fig. 9). It is clear that the level of mineralised tissue is signifi- cantly higher in those areas where stem cells were applied (Figs. 10a & b). Evidently, although bone mar- row stem cell techniques for bone reconstruction are very close to routine clinical use, much caution must be exer- cised before indicating such a procedure. This procedure re- quires an appropriately trained surgical and laboratory team, as well as the availability of the necessary resources (Figs. 11a–h, taken during laboratory manipulation of marrow stem cells at São Leopoldo Mandic dental school in Brazil). References [1] André Antonio Pelegrine, Antonio Carlos Aloise, Allan Zimmermann et al., Repair of critical-size bone defects using bone marrow stromal cells: A histomorphometric study in rabbit calvaria. Part I: Use of fresh bone marrow or bone marrow mononuclear frac- tion, Clinical Oral Implants Re- search, 00 (2013): 1–6. [2] André Antonio Pelegrine, Antonio Carlos Aloise & Carlos Eduardo Sorgi da Costa, Célu- las Tronco em Implantodontia (São Paulo: Napoleão, 2013). Dr André Antonio Pelegrine is a specialist dental surgeon in per- iodontology and implant dentist- ry (CFO) with an MSc in Implant Dentistry (UNISA), and a PhD in clinical medicine (University of Campinas). He completed post- doctoral research in transplant surgery (Federal University of São Paulo). He is an associate lecturer in im- plant dentistry at São Leopoldo Mandic dental school and co- ordinator of the perio-prostho- dontic-implant dentistry team at the University of Campinas in Brazil. He can be contacted at pel- egrineandre@gmail.com. About The Author