Abstract
Vital pulp therapy (VPT) is to preserve the nerve and maintain healthy dental pulp tissue. Laser irradiation (LI) is beneficial for VPT. Understanding how LI affects dental pulp cells and tissues is necessary to elucidate the mechanism of reparative dentin and dentin regeneration. Here, we show how Er:YAG-LI and diode-LI modulated cell proliferation, apoptosis, gene expression, protease activation, and mineralization induction in dental pulp cells and tissues using cell culture, immunohistochemical, genetic, and protein analysis techniques. Both LIs promoted proliferation in porcine dental pulp-derived cell lines (PPU-7), although the cell growth rate between the LIs was different. In addition to proliferation, both LIs also caused apoptosis; however, the apoptotic index for Er:YAG-LI was higher than that for diode-LI. The mRNA level of odontoblastic gene markers—two dentin sialophosphoprotein splicing variants and matrix metalloprotease (MMP)20 were enhanced by diode-LI, whereas MMP2 was increased by Er:YAG-LI. Both LIs enhanced alkaline phosphatase activity, suggesting that they may help induce PPU-7 differentiation into odontoblast-like cells. In terms of mineralization induction, the LIs were not significantly different, although their cell reactivity was likely different. Both LIs activated four MMPs in porcine dental pulp tissues. We helped elucidate how reparative dentin is formed during laser treatments.
Highlights
Vital pulp therapy (VPT) encompasses clinical interventions to preserve the nerve as much as possible, and to maintain healthy pulp tissue
Cell proliferation under the diode laser rapidly decreased at the same rate as the control, whereas the Erbium-doped yttrium aluminum garnet (Er):YAG laser-treated cells showed a gradual downward trend
The cell number of Er:YAG-Laser irradiation (LI) began to decrease in the second day, and it was lower than control (1.42-fold) and diode-LI (1.51-fold) in the third day
Summary
Vital pulp therapy (VPT) encompasses clinical interventions to preserve the nerve as much as possible, and to maintain healthy pulp tissue. Erbium-doped yttrium aluminum garnet (Er:YAG) lasers have numerous applications in a wide range of medical, and dental fields. Er:YAG lasers have high water absorbency compared to CO2 and neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers [5]. Due to this characteristic, Er:YAG lasers are well absorbed in biological tissues containing water, and used for various treatments, such as cementum transpiration of the root surface, tartar, bone tissue, and gingival soft tissue [6,7,8,9,10,11]. Unlike Er:YAG lasers, which are absorbed on the tissue surface, diode lasers are transmitted to internal tissue and used for incision, hemostatic coagulation, and pain relief for intraoral soft tissue [12,13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
