Effects of triethylene glycol dimethacrylate (TEGDMA) on the odontoclastic differentiation ability of human dental pulp cells.

OBJECTIVES: The primary purpose of this study was to examine the effects of triethylene glycol dimethacrylate (TEGDMA) on odontoclastic differentiation in the dental pulp tissue. MATERIAL AND METHODS: The effects of different TEGDMA dosages on the odontoclastic differentiation capability of dental pulp cells were analyzed in vitro using the following methodologies: i) flow cytometry and tartrate-resistant acid phosphatase (TRAP) staining; ii) apoptotic effects using Annexin V staining; iii) mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor (NF)-kB ligand (RANKL) genes by quantitative Real-time PCR (qRT-PCR); and iv) OPG and RANKL protein expression by enzyme-linked immunosorbent assay (ELISA). RESULTS: TEGDMA caused relatively less odontoclastic differentiation in comparison with the control group; however, odontoclastic differentiation augmented with increasing doses of TEGDMA (p<0.05). The mRNA and protein expression of OPG was lower in TEGDMA treated pulp cells than in the control group (p<0.05). While the mRNA expression of RANKL remained unchanged compared to the control group (p>0.05), its protein expression was higher than the control group (p<0.05). In addition, TEGDMA increased the apoptosis of dental pulp cells dose dependently. CONCLUSIONS: TEGDMA reduced the odontoclastic differentiation ability of human dental pulp cells. However, odontoclastic differentiation ratios increased proportionally with the increasing dose of TEGDMA.

Effects of triethylene glycol dimethacrylate (TEGDMA) on the odontoclastic differentiation ability of human dental pulp cells

Abstract Objectives: The primary purpose of this study was to examine the effects of triethylene glycol dimethacrylate (TEGDMA) on odontoclastic differentiation in the dental pulp tissue. Material and Methods: The effects of different TEGDMA dosages on the odontoclastic differentiation capability of dental pulp cells were analyzed in vitro using the following methodologies: i) flow cytometry and tartrate-resistant acid phosphatase (TRAP) staining; ii) apoptotic effects using Annexin V staining; iii) mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor (NF)-kB ligand (RANKL) genes by quantitative Real-time PCR (qRT-PCR); and iv) OPG and RANKL protein expression by enzyme-linked immunosorbent assay (ELISA). Results: TEGDMA caused relatively less odontoclastic differentiation in comparison with the control group; however, odontoclastic differentiation augmented with increasing doses of TEGDMA (p<0.05). The mRNA and protein expression of OPG was lower in TEGDMA treated pulp cells than in the control group (p<0.05). While the mRNA expression of RANKL remained unchanged compared to the control group (p>0.05), its protein expression was higher than the control group (p<0.05). In addition, TEGDMA increased the apoptosis of dental pulp cells dose dependently. Conclusions: TEGDMA reduced the odontoclastic differentiation ability of human dental pulp cells. However, odontoclastic differentiation ratios increased proportionally with the increasing dose of TEGDMA.

Hypoxia inhibits mineralization ability of human dental pulp cells treated with TEGDMA but increases cell survival in accordance with the culture time.

OBJECTIVE: To evaluate the cytotoxicity and mineralization effects of TEGDMA in human dental pulp cells (hDPCs) under hypoxic and normoxic culture conditions. DESIGN: Cell viability was evaluated using XTT assay after incubation periods of 24, 48, or 72h. The expression of mineralization-related genes (osteonectin, osteopontin, dentin sialophosphoprotein, collagen type 1) and heme oxygenase 1 (HO-1) was assessed by quantitative real-time polymerase chain reaction at 24 and 72h. RESULTS: In XTT assay, viability was higher in 0.3, 1, 2, 4, and 5mM groups in the presence of 21% O2 after 24h (p<0.05). Additionally, while 0.3, 1, 2mM groups had higher cell viability in the presence of 21% O2 after 48h (p<0.05), in 3mM groups cell viability was higher under 3% O2 than 21% O2 after both 24 and 48h (p<0.05). 1-3mM groups had higher cell viability under 3% O2 after 72h (p<0.05). There was no difference between 4 and 5mM groups with regards to cell viability after 48 or 72h (p>0.05). In the gene expression study, TEGDMA-treated hDPCs showed lower mineralization potential in the presence of 3% than with 21% O2 (p<0.05). hDPCs revealed higher HO 1 expression in 0.3 and 1mM groups under hypoxic than under normoxic conditions after a 72-h time period (p<0.001). CONCLUSIONS: Hypoxic conditions increased cell survival in accordance with the culture period but inhibited the odontoblastic differentiation of hDPCs treated with TEGDMA.

Selective 5-HT7 receptor agonists LP 44 and LP 211 elicit an analgesic effect on formalin-induced orofacial pain in mice.

OBJECTIVE: To investigate the antinociceptive effects of pharmacological activation of 5-HT7 receptors on orofacial pain in mice. MATERIAL AND METHODS: Nociception was evaluated by using an orofacial formalin test in male Balb-C mice. Selective 5-HT7 receptor agonists, LP 44 and LP 211 (1, 5, and 10 mg/kg), were given intraperitoneally 30 min prior to a formalin injection. A bolus of 10 µl of 4% subcutaneous formalin was injected into the upper lip of mice and facial grooming behaviors were monitored. The behavioral responses consisted of two distinct periods, the early phase corresponding to acute pain (Phase I: 0-12 min) and the late phase (Phase II: 12-30 min). RESULTS: LP 44 and LP 211 (1, 5, and 10 mg/kg) produced an analgesic effect with reductions in face rubbing time in both Phase I and Phase II of the formalin test. CONCLUSION: Our results suggest that 5-HT7 receptor agonists may be promising analgesic drugs in the treatment of orofacial pain.

Selective 5-HT7 receptor agonists LP 44 and LP 211 elicit an analgesic effect on formalin-induced orofacial pain in mice

ABSTRACT The most recently identified serotonin (5-HT) receptor is the 5-HT7 receptor. The antinociceptive effects of a 5-HT7 receptor agonist have been shown in neuropathic and inflammatory animal models of pain. A recent study demonstrated the functional expression of 5-HT7 receptors in the substantia gelatinosa (SG) of the trigeminal subnucleus caudalis, which receives and processes orofacial nociceptive inputs. Objective To investigate the antinociceptive effects of pharmacological activation of 5-HT7 receptors on orofacial pain in mice. Material and Methods Nociception was evaluated by using an orofacial formalin test in male Balb-C mice. Selective 5-HT7 receptor agonists, LP 44 and LP 211 (1, 5, and 10 mg/kg), were given intraperitoneally 30 min prior to a formalin injection. A bolus of 10 µl of 4% subcutaneous formalin was injected into the upper lip of mice and facial grooming behaviors were monitored. The behavioral responses consisted of two distinct periods, the early phase corresponding to acute pain (Phase I: 0–12 min) and the late phase (Phase II: 12–30 min). Results LP 44 and LP 211 (1, 5, and 10 mg/kg) produced an analgesic effect with reductions in face rubbing time in both Phase I and Phase II of the formalin test. Conclusion Our results suggest that 5-HT7 receptor agonists may be promising analgesic drugs in the treatment of orofacial pain.

In vivo evaluation of the effects of hydraulic calcium silicate dental cements on plasma and liver aluminium levels in rats.

Our aim was to test whether the presence of three hydraulic calcium silicate dental cements--MTA Angelus, MTA Fillapex, and Theracal LC--in the dental extraction socket of an in vivo model, would affect the levels of aluminium (Al) in the plasma and liver. Following anesthesia, the right upper incisor of each male Wistar albino rat was extracted and polyethylene tubes filled with MTA Angelus, MTA Fillapex, or Theracal LC were inserted into the depth of the extraction socket and gingival tissue was sutured. The rats were killed 7, 30, or 60 d after the operation. Blood and liver samples were obtained from the rats before they were killed, and the levels of Al were measured by atomic absorption spectrometry. Plasma Al levels were higher in the rats in which the mineral trioxide aggregate (MTA) cements were implanted, especially MTA Angelus and MTA Fillapex, compared with control rats. In liver samples, however, the differences in Al level were not statistically significant. Our results show that Al might have been released into the circulation from the three dental cements tested, especially MTA Angelus and MTA Fillapex. Further research should be carried out on the possible biological effects of Al liberated from dental cements.