RESUMEN

Background: Direct pulp capping is a vital pulp therapy, which stimulates differentiation of stem cells from apical papilla (SCAPs). SCAPs have multipotential capacity to differentiate into types of cells, contributing to the regeneration of tissues. Objective: Considering the promising effects of dental-capping materials, we aim to investigate the effect of dental dressing materials combined with laser therapy on the percentage of SCAP viability and the consequent dental regeneration capacity. Methods: We collected two immature third molar teeth and isolated SCAPs through collagenase type I enzymatic activity. Isolated SCAPs were then cultured with Dulbecco's modified Eagle's medium and α-minimum essential medium enriched with 15% and 10% fetal bovine serum, respectively. After reaching 70-80% confluency, cells were seeded in a 96-well plate and then treated with mineral trioxide aggregate (MTA), enamel matrix derivative (EMD), biodentine, and low level laser therapy (LLLT) alone and in combination for 24, 48, and 168 h. After that, cell survival rate was assessed using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay. Results: We found that combination of MTA, EMD, and LLLT as well as that of biodentine, EMD, and LLLT could lead to significant increase of SCAP viability as compared with other treatment groups. Combination of MTA and biodentine with EMD could also show increased level of SCAP proliferation and viability. However, MTA and biodentine alone reduced SCAP survival rate in all time points. Conclusions: Our conclusion is that LLLT can serve as an enhancer of SCAP proliferation and differentiation rate when added to dental-capping agents such as MTA, EMD, and biodentine. Thus, LLLT combination with effective capping materials will serve as a promising option for dental tissue repair.

Asunto(s)

Terapia por Luz de Baja Intensidad , Compuestos de Calcio/farmacología , Células Madre , Proliferación Celular

RESUMEN

Introduction: Dental pulp capping is a technique that is highly applicable in dental restorations. In this technique, a material is directly placed over the exposed pulp tissue, which promotes pulp healing and generates reparative dentin. Herein, we aimed to investigate the combined effect of different pulp capping agents, including mineral trioxide aggregate (MTA), Emdogain (EMD), calcium-enriched mixture (CEM), and low-level laser therapy (LLLT), on enhancing viability and proliferation of stem cells from apical papilla (SCAPs). Methods: SCAPs were isolated from two immature third molar teeth through collagenase type I enzymatic activity. Isolated stem cells were then cultured with DMEM and α-MEM media enriched with 15% and 10% FBS respectively. After reaching 70%-80% confluency, the cells were seeded in a 96-well plate. Cell viability percent was assessed using the MTT assay after treatment with MTA, EMD, CEM and LLLT (λ=630 nm, 5 mW, 4 J/cm2 ) alone and in combination for 24, 48 and 168 hours. Results: Combination of MTA, CEM, EMD and LLLT resulted in significantly increased SCAPs viability as compared with other treatment groups. Increased SCAPs proliferation and viability were also observed in groups treated with the combination of MTA and CEM with EMD. However, the SCAPs survival rate in all defined time spans was reduced after treatment with MTA and CEM alone. Conclusion: LLLT can be a stimulator of SCAPs cell viability when applied in combination with dental capping agents such as MTA, EMD and CEM, providing a therapeutic option for stem cell-based dental regeneration.

RESUMEN

OBJECTIVES: This study aimed to evaluate the effects of chlorhexidine mouthrinses on color stability of nanofilled and micro-hybrid resin-based composites. MATERIALS AND METHODS: In this in-vitro study, 160 disc-shaped specimens (7x2mm) were fabricated of Filtek Z250 and Filtek Z350XT Enamel (A2 shade). The samples of each group were randomly divided into eight subgroups (n=10). The specimens were incubated in artificial saliva at 37°C for 24 hours. The baseline color values (L*, a*, b*) of each specimen were measured according to CIE LAB system using a reflection spectrophotometer. After baseline color measurements, the control samples were immersed in saliva and the test groups were immersed in Kin (Cosmodent), Vi-One (Rozhin), Epimax (Emad), Hexodine (Donyaye Behdasht), Chlorhexidine (Shahrdaru), Najo (Najo) and Behsa (Behsa) mouthrinses once a day for two minutes. The specimens were then immersed again in saliva. This process was repeated for two weeks. Color measurements were made on days seven and 14. Two-way and one-way ANOVA and Tukey's post hoc test, t-test and paired t-test were used to analyze data at a significance level of 0.05. RESULTS: All specimens displayed color change after immersion in the mouthrinses. Significant interactions were found between the effects of materials and mouthrinses on color change. CONCLUSIONS: All composite resins tested showed acceptable color change after immersion in different mouthrinses. Filtek Z350XT showed less color change than Filtek Z250. Mouthrinses containing alcohol (Behsa and Najo) and citric acid (Vi-One) caused greater discoloration of composites.