A positive effect of low-level laser irradiation (LLLI) on the proliferation of some cell types has been observed, but little is known about its effect on dental pulp stem cells (DPSCs). The aim of this study was to identify the lowest energy density able to promote the proliferation of DPSCs and to maintain cell viability. Human DPSCs were isolated from two healthy third molars. In the third passage, the cells were irradiated or not (control) with an InGaAlP diode laser at 0 and 48 h using two different energy densities (0.5 and 1.0 J/cm²). Cell proliferation and viability and mitochondrial activity were evaluated at intervals of 24, 48, 72, and 96 h after the first laser application. Apoptosis- and cell cycle-related events were analyzed by flow cytometry. The group irradiated with an energy density of 1.0 J/cm² exhibited an increase of cell proliferation, with a statistically significant difference (p < 0.05) compared to the control group at 72 and 96 h. No significant changes in cell viability were observed throughout the experiment. The distribution of cells in the cell cycle phases was consistent with proliferating cells in all three groups. We concluded that LLLI, particularly a dose of 1.0 J/cm², contributed to the growth of DPSCs and maintenance of its viability. This fact indicates this therapy to be an important future tool for tissue engineering and regenerative medicine involving stem cells.

NeoMTA Plus, Biodentine, and MTA Angelus were not effective against multispecies microcosm biofilm. It is essential to understand that these bioceramic cements are indicated for infected clinical situations. Thus, complementary disinfection procedures should be conducted prior to filling with these materials.

This study aimed to compare apical transportation, centering ratio, and working time during root canal preparation with Wizard Navigator (WN), WaveOne (WO), or ProTaper Universal (PT) and to describe deformation and fracture of these instruments. Thirty-six mesiobuccal roots from maxillary molars were micro-computed tomography (micro-CT) scanned and then sorted into three groups (n = 12): Wizard Navigator (WN), WaveOne (WO), and ProTaper Universal (PT). The root canals were prepared using WN, WO, or PT; the time of each canal preparation was timed; and the specimens were micro-CT re-scanned. The instruments were submitted to scanning electron microscopy (SEM) before and after their use. The data on canal transportation at 1, 2, 3, 4 and 5 mm and preparation time were analyzed by the Kruskal-Wallis test, followed by the Mann-Whitney U test. The centering ratio was analyzed by ANOVA, followed by Tukey's test. Both instrument deformation and fracture were described. Apical transportation was similar among groups at 1, 2, 3 and 4 mm. The WO group showed higher canal transportation at 5mm than the other groups (p = 0.03). There was no significant difference in centering ratio among the groups. Preparation time in the WO group was significantly lower than in the other groups (p = 0.004). Small differences were observed in the surface area of all instruments. The WN, WO, and PT groups had a similar centering ratio without procedural errors or significant structural changes. At 5 mm from the apex, the WO group showed the largest canal transportation toward the furcation and root canal preparation was faster than in the WN and PT groups.

Objectives: This study aimed to evaluate the cell viability and migration of Endosequence Bioceramic Root Canal Sealer (BC Sealer) compared to MTA Fillapex and AH Plus. Materials and Methods: BC Sealer, MTA Fillapex, and AH Plus were placed in contact with culture medium to obtain sealers extracts in dilution 1:1, 1:2 and 1:4. 3T3 cells were plated and exposed to the extracts. Cell viability and migration were assessed by 3-(4,5-dimethylthiazoyl)-2,5-diphenyl-tetrazolium bromide (MTT) and Scratch assay, respectively. Data were analyzed by Kruskal-Wallis and Dunn's test (p < 0.05). Results: The MTT assay revealed greater cytotoxicity for AH Plus and MTA Fillapex at 1:1 dilution when compared to control (p < 0.05). At 1:2 and 1:4 dilutions, all sealers were similar to control (p > 0.05) and MTA Fillapex was more cytotoxic than BC Sealer (p < 0.05). Scratch assay demonstrated the continuous closure of the wound according to time. At 30 hours, the control group presented closure of the wound (p < 0.05). At 36 hours, only BC Sealer presented the closure when compared to AH Plus and MTA Fillapex (p < 0.05). At 42 hours, AH Plus and MTA Fillapex showed a wound healing (p > 0.05). Conclusions: All tested sealers demonstrated cell viability highlighting BC Sealer, which showed increased cell migration capacity suggesting that this sealer may achieve better tissue repair when compared to other tested sealers.

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This study aimed to evaluate the role of photobiomodulation (PBM) in apexification and apexogenesis of necrotic rat molars with an open apex. Rat molars were exposed to the oral environment for 3 weeks. Canals were rinsed with 2.5% NaOCl and 17% EDTA, filled with antibiotic paste and sealed. After 7 days, canals were rinsed and divided into six groups (n=6): mineral trioxide aggregate (MTA); blood clot (BC); human dental pulp stem cells (hDPSC); MTA+PBM; BC+PBM; and hDPSC+PBM. In hDPSC groups, a 1% agarose gel scaffold was used. Two groups were not exposed: healthy tooth+PBM (n = 6), healthy tooth (n = 3); and one was exposed throughout the experiment: necrotic tooth (n = 3). In PBM groups, irradiation was performed with aluminum gallium indium phosphide (InGaAlP) diode laser for 30 days within 24-h intervals. After that, the specimens were processed for histological and immunohistochemical analyses. Necrotic tooth showed greater neutrophil infiltrate (p < 0.05). Necrotic tooth, healthy tooth, and healthy tooth+PBM groups showed absence of a thin layer of fibrous condensation in the periapical area. All the other groups stimulated the formation of a thicker layer of fibers (p < 0.05). All groups formed more mineralized tissue than necrotic tooth (p < 0.05). PBM associated with MTA, BC, or hDPSC formed more mineralized tissue (p < 0.05). MTA+PBM induced apexification (p < 0.05). Rabbit polyclonal anti-bone sialoprotein (BSP) antibody confirmed the histological findings of mineralized tissue formation, and hDPSC groups exhibited higher percentage of BSP-positive cells. It can be concluded that PBM improved apexification and favored apexogenesis in necrotic rat molars with an open apex.

Photobiomodulation therapy (PBM) has shown positive effects on stem cell differentiation in monolayer cell culture model, but little is known about its effect on three-dimensional (3-D) agarose gel culture. This study evaluated the PBM effect of human dental pulp stem cells (hDPSCs) differentiation and phosphatase alkaline activity (ALP) using an agarose 3-D model under different nutritional conditions. hDPSCs were characterized and seeded on a 0.3% agarose gel layer with different media (osteogenic, adipogenic, chondrogenic) and were assigned into four groups: control 10% fetal bovine serum (FBS), control 5% FBS, PBM 10% FBS, and PBM 5% FBS. Irradiation was performed with continuous-wave InGaAlP laser, 660 nm, 100 mW, 3,3  J  /  cm2, spot size 0.3  cm2, 10 s of exposure time, and 1 J of energy per point with 6-h interval between sessions. All groups were evaluated at 7 and 14 days. ALP assay was performed to analyze the deposition of mineralized tissue. At 7 days, PBM 5% FBS group presented better stimulation in osteogenic and adipogenic differentiation compared with control. After 14 days, hDPSCs cultured in 3-D exhibited osteogenic, adipogenic, and chondrogenic differentiation; furthermore, compared to control, PBM significantly stimulated all differentiation processes (p < 0.05). It can be concluded that hDPSCs cultured in 3-D agarose associated to PBM could be a promising tool for tissue engineering applications.

Context:Accidental root canal perforations are among the main complications of endodontic treatment.Aim:This study evaluated the influence of operating microscope (OM) in the marginal adaptation of mineral trioxide aggregate (MTA) (Angelus®) and glass ionomer (Vitremer) inserted into cervical perforations.Materials and Methods:Perforations were made in the cervical third of the buccal wall of the root canal in mandibular incisors. Next, the teeth were divided into four groups (N = 10): MG — MTA without OM; VG — Vitremer without OM; MOMG — MTA with OM; VOMG — Vitremer with OM. The perforations were sealed according to the group and the teeth were prepared for analysis by confocal laser scanning microscope. Images of perforation region (1,024×) were made and the gap presented by the materials was measured using the Image J program. LEXT OLS4100 three dimensional (3D) measuring laser microscope measured the volumetric misfit. Data of gap were analyzed by Kruskal-Wallis and Dunn's tests. Analysis of variance (ANOVA) and Tukey's tests compared the volumetric misfits.Results:The results showed lower volume and gap in the interface dentin/material in VOMG compared to the other groups (P < 0.05).Conclusion:The use of OM improved the quality of cervical perforations sealed with Vitremer, being indicated in clinical situations of iatrogenic cervical perforations.