Evidence based dentistry is a combination of the best available research evidence with clinical experience and patient needs. Systematic reviews are labor intensive and require expertise in the subject matter and review methods. The arena of endodontic material science is continuing to evolve with the newer materials constantly being introduced to the market with advantageous properties. Countless teeth with questionable prognosis are now salvageable but there is a need to collect clinical evidence on the performance of these materials. This systematic review is one such attempt for recording and cataloguing the evidence to identify the role of Tricalcium silicate cements in osseous healing.
Tricalcium-silicate based cements (TCSC) were first introduced to dentistry in 1993 when Torabinejad developed a formula based on ordinary Portland cement (OPC) to produce mineral trioxide aggregate (MTA). MTA has been recognized as the gold standard material for a variety of clinical situations due to its biocompatibility, alkalinity (pH value 12.5), sealing ability, and bioactivity. A wide selection of commercial TCSC materials based on the original formulation and/or with minor modifications which possess many similar and some different in vitro and in vivo characteristics are now available. They are shown to upregulate the differentiation of osteoblasts, fibroblasts, cementoblasts, odontoblasts, pulp cells and many stem cells. These properties have led to a growing series of innovative clinical applications such as their use as root repair materials, root canal sealers as well as orthograde or retrograde root canal filling materials.
Of particular interest to clinicians and researchers is the ability of TCSC to induce osteogenic responses when they are applied to bone defects (i.e. osteoactivity). TCSC are known to have good interaction with bone forming cells and their bioactive potential is responsible for the clinical success when these cements are used. Lee et al analyzed effects of endodontic bioactive cements on osteogenic differentiation in mesenchymal stem cells. They found that tricalcium silicate based cements induce osteoblast differentiation in different stem cells. Messenger RNA level of osteogenic genes, including ALP, osteocalcin and bone sialoprotein, was increased after exposure to these cements for 3 days. Torabinejad et al. found that dentoalveolar healing adjacent to the MTA root-end fillings results in regeneration of the periapical tissues, including apical cementogenesis. Moreover, Mitchell et al. showed successful growth of osteoblast cells adjacent to MTA.
Evidence regarding cementogenesis and osteogenic capacity of MTA has been amassed. Koh et al. investigated the biological response in human osteoblasts and found increased osteocalcin production when cells were grown on MTA, and also, cells in contact with MTA appeared to have high levels of alkaline phosphatase. Various other studies like that of Nascimento et al. showed that the use of MTA in bone defects was able to induce bone regeneration. Studies by Al-Rabeah et al. demonstrated the capacity of MTA to support osteoblast cell attachment, proliferation, and matrix formation.
It should be noted that the supporting data have been overwhelmingly from either in vitro or animal studies about osseous repair capacity of MTA. However, there is a distinct need to examine the clinical performance of MTA and other tricalcium silicate cements in well-designed and controlled clinical studies. Hence, the purpose of this study was to systematically review the published osseous healing outcome of root repair by tricalcium silicate based cements.
