Photobiomodulation vs NSAIDs in the management of postoperative dentoalveolar pain

BackgroundPostoperative pain, the most common complication of dentoalveolar surgery, is routinely controlled by non-steroidal anti-inflammatory drugs (NSAIDs). However, despite its proven efficacy, the long-term consumption of NSAIDs is associated with several serious and adverse effects. As a result, photobiomodulation (PBM) or low-level laser therapy (LLLT) is used in many treatment modalities to reduce pain, inflammation, and promote healing.Aim of the studyTo compare the analgesic effects of LLLT and Ibuprofen after surgical dental extraction.Materials and methodsA clinical trial study was conducted at Umm Al-Qura University Dental Clinics, involving 46 healthy patients between 20 and 60 years of age. The recruited patients were divided into two groups of 23 patients each. Group 1 (positive control group) was prescribed Ibuprofen and Group 2 (experimental group) was treated with LLLT. The pain was measured on days 1, 2, and 7 using the Numeric Pain Rating Scale (NPRS).ResultsThe mean level of pain decreased with both treatments. On the first postoperative day, the pain level in the laser therapy group was significantly lower than in the control group (U = 62.5, p = 0.024). The results indicated a significant decrease in pain level on the second postoperative day for both the control and experimental groups (Z = ?3.61, p < 0.005, and Z = ?3.1, p = 0.002, respectively). However, the pain level was lower in the control group, although the difference was not statistically significant (U = 79, p = 0.102).ConclusionConsidering the constraints of this study, NSAIDs were found to be significantly better at reducing pain than LLLT.     

Impact of SARS-CoV-2 on saliva: TNF-⍺, IL-6, IL-10, lactoferrin,lysozyme, IgG,IgA, and IgM

ObjectivesUnderstanding the role of certain salivary components, such as TNF-?, IL-6, IL-10, lactoferrin, lysozyme, IgG, IgA, and IgM, in airway defense during the ongoing SARS-CoV-2 pandemic is essential. The salivary immune barrier of patients with COVID-19 may play a role in their prognosis. The present study aims to evaluate the impact of SARS-CoV-2 on saliva composition.MethodsA longitudinal study was carried out with male and female firefighters aged 24–48 years. The study sample (n = 34) was divided into 3 groups: asymptomatic volunteers with a negative polymerase chain reaction (PCR) test for SARS-CoV-2 (group 1, Control, n = 21); patients with symptoms of COVID-19 of less than 7 days’ duration and a diagnosis of SARS-CoV-2 infection by PCR (group 2, COVID-19, n = 13); and recovered patients from group 2 who were free of COVID-19 symptoms for at least 2 months (group 3, post-COVID-19 recovery, n = 13). All groups underwent real-time PCR to detect the presence of SARS-CoV-2, as well as analysis of the salivary concentrations of TNF-?, IL-6, IL-10, lactoferrin, lysozyme, IgG, IgA, and IgM by the ELISA method.ResultsLactoferrin concentrations were significantly decreased in the infected group (COVID-19) when compared to those not infected by SARS-CoV-2 (control) (p = 0.032). IgA concentrations were decreased in the COVID-19 and post-COVID-19 groups compared to the control group (p = 0.005 and p = 0.016, respectively). Comparison of the COVID-19 and post-COVID-19 groups also revealed an increase in IgM concentrations during acute SARS-CoV-2 infection (p = 0.010).ConclusionSARS-CoV-2 alters the composition of the salivary immune barrier.     

Proanthocyanidin encapsulation for sustained bioactivity in dentin bioadhesion: A two-year study

ObjectivesTo determine the long-term effect on the stability of dentin-resin interfaces after the addition of polylactide (PLA) capsules containing proanthocyanidin (PAC) to adhesive resin.MethodsSub-micron (SM) and micron (M) size capsules containing PACs were produced using a combination of emulsification and solvent evaporation techniques and characterized. Human dentin surfaces (n = 8) were etched (35% glycolic acid) and primed (15% enriched Vitis vinifera extract solution - VV_e), followed by the application of an experimental adhesive containing 0 (control), 1.5 wt% of SM or M PAC-filled PLA capsules light cured for 40 s. A crown was built using commercial composite. After 24 h-immersion (37 °C) in simulated body fluid, specimens were serially sectioned into resin-dentin beams. Microtensile bond strength (TBS), micro-permeability and fracture pattern were assessed immediately and after 1 and 2 years. Data were statistically analyzed using two-way ANOVA and post-hoc test (α = 0.05).ResultsPolydisperse capsules were manufactured with average diameter of 0.36 µm and 1.08 µm for SM and M, respectively. The addition of capsules did not affect TBS (p = 0.889). After 2 years, TBS significantly decreased in SM (p = 0.006), whereas M showed similar initial values (p = 0.291). Overall, less micro-permeability was found in M than the control and SM group (p < 0.001). After 2 years, fractured surfaces from capsule-containing groups failed within the adhesive layer while control fractured at the bottom of the hybrid layer.SignificanceThe addition of PAC-filled PLA microcapsules in a dental adhesive did not affect the bond strength while increased and sustained the protection against micro-permeability in the interface, likely due to release of PACs.     

Association between rs11362 polymorphism in the beta-defensin 1 (DEFB1) gene and dental caries: A meta-analysis

ObjectivesBeta-defensin 1, encoded by the DEFB1 gene, is an important molecule that confers protection from dental caries. Numerous studies have been conducted on the rs11362 polymorphism in the DEFB1 gene. We evaluated the results from studies that have investigated the association between rs11362 polymorphism and dental caries, through a meta-analysis.MethodsThis meta-analysis was designed according to the PRISMA statement guideline. Electronic databases (PubMed, Web of Science, Scopus, and Cochrane Library) were scanned by two independent researchers. The publication bias was determined by statistical analyses using funnel plot, Egger regression test, and Begg and Mazumdar rank correlation test. Heterogeneity was evaluated using the chi-square test, tau-square, and Higgins I² test. Odds ratio (OR) was used to measure the effect size.ResultsRank correlation and regression procedures showed the absence of publication bias in the meta-analysis (p > 0.05). The DEFB1 rs11362 polymorphism in the heterozygous (CC vs. CT: OR = 2.20, 95% confidence interval (CI): 1.17, 4.10; p = 0.014) and dominant (CC vs. CT + TT: OR = 3.11, 95% CI: 1.18, 8.21; p = 0.022) models in the permanent dentition subgroup showed significant differences. However, there was no significant difference between any model in either the deciduous dentition (p > 0.05) or the mixed dentition subgroups (p > 0.05).ConclusionsThis meta-analysis suggests that the DEFB1 rs11362 polymorphism is associated with dental caries in permanent dentition. Moreover, individuals with the TT genotype were found to have seven times higher risk of dental caries than individuals with the CC genotype. There was no such association or statistical difference observed for deciduous and mixed dentitions.     

In-vitro cytocompatibility of self-adhesive dual-curing resin cements on human mesenchymal stem cells (hMSC) and periodontal ligament cells (PDL-hTERT)

ObjectivesSelf-adhesive dual cured resin cements provide easier clinical application than conventional resin cements but release higher amounts of unreacted monomers, potentially affecting their biocompatibility. This study aimed to compare the cytotoxic effects of self-adhesive dual cured resin cements with two conventional resin cements.MethodsSamples of four resin cements, two self-adhesive dual cured cements (group A: RelyX Unicem, group B: SmartCem), and two conventional resin cements (group C: Panavia 2.0, group D: Variolink Esthetic DC) were prepared with a similar dimension under standardized polymerization conditions and stored in water. For each material 18 samples were used and cell cultures of human mesenchymal stem cells (hMSCs) or periodontal ligament cells (PDL-hTERT) were added under appropriate conditions. One experimental group (group E) was left untreated as control. A cell viability WST test, was performed in each experimental group at day 1, 7, 14 and 21. Moreover, microscopic examination of cells was performed using cell viability staining.ResultsViability of both cell types as determined by WST test was significantly impaired at all time periods by the four different cement materials compared to the untreated control. Comparison between the four materials revealed different inhibition of the viability of both, PDL-hTERT and hMSC cells (group C > group B > group A > group D; p < 0.0001).SignificanceAll resin-based cements caused significant impairment of cell viability, reflecting considerable cytotoxicity. Variolink caused significantly smaller changes of viability than the other tested materials.     

The influence of periodontal status and serum biomarkers on salivary leptin levels in systemic lupus erythematosus patients

ObjectiveThis study aimed to investigate the influence of periodontal status, clinical data, and serum markers on salivary leptin levels in patients with systemic lupus erythematosus (SLE).MethodsA case–control study was conducted with 38 patients with SLE and 29 healthy controls. Periodontal data included periodontal probing depth (PPD), clinical attachment level (CAL), and gingival bleeding on probing (BOP). Stimulated saliva samples were collected to analyze salivary leptin levels. Clinical and serum data were collected from the SLE group. Statistical analysis included the t-test, Mann–Whitney test, Spearman correlation coefficient, and a structural equation model.ResultsThe SLE group had a lower salivary leptin level than the control group (P = 0.002). The model revealed that SLE had an inverse and independent effect on salivary leptin (standardized estimate =  ? 0.289, P = 0.023). Moreover, salivary leptin level negatively correlated with the serum levels of triglyceride, creatinine, and leukocytes, positively correlated with the serum total cholesterol, but was not significantly correlated with the periodontal status.ConclusionThese findings suggest that patients with SLE have a lower salivary leptin level. In addition, the level of salivary leptin does not appear to be related to periodontal status in patients with SLE.     

Five-year clinical evaluation of universal adhesive applied following different bonding techniques: A randomized multicenter clinical trial

ObjectivesTo evaluate the clinical performance of a universal adhesive system (Futurabond U, Voco) when applied following different adhesive strategies in non-carious cervical lesions (NCCLs) after 5 years.MethodsFifty participants were included. Futurabond U (Voco) was applied in NCCLs using four adhesive strategies (n = 50 each): only self-etch (SE); selective enamel etching + self-etch (SET + SE); etch-and-rinse with dry dentin (ERD); and etch-and-rinse with wet dentin (ERW). All cavities were restored with Admira Fusion composite resin (Voco). Restorations were evaluated after 1, 3, and 5 years using the World Federation criteria (FDI) and the modified United States Public Health Service (USPHS) criteria.ResultsAfter 5 years, retention rates were 81 % (65.8–90.5) for SE, 87 % (73.2–94.4) for SET + SE, 84 % (69.6–92.6) for ERD, and 78 % (63.6–88.9) for ERW (p > 0.05). Thirty-five restorations were considered to have minor discrepancies in marginal adaptation at the 5-year recall (14 for SE, 9 for SET + SE, 6 for ERD, and 6 for ERW; p > 0.05). Sixteen restorations were detected as a minor marginal discoloration (6 for SE, 4 for SET + SE, 1 for ERD, and 5 for ERW; p > 0.05) and one restoration showed a recurrence of caries (1 for ERW; p > 0.05) at the 5-year recall. No restorations showed postoperative sensitivity after 5 years.SignificanceNCCLs restorations using a universal adhesive showed satisfactory clinical performance after 5 years, regardless of the adhesive strategy.     

Assessment of the prevalence and configuration of middle distal canals in the mandibular molars in a Saudi subpopulation using Cone-Beam computed tomography

PurposeThe prevalence of the middle distal (MD) canal in the mandibular molar is significantly low among countries including the USA, Spain, Turkey, and Jordan; however, analysis of its prevalence and configuration has not been performed in Saudi Arabia. Therefore, we aimed to assess the prevalence and configuration of the MD canal in Saudi Arabia.MethodsA retrospective analysis of 132 cone-beam computed tomography (CBCT) images was performed to evaluate the presence of the MD canal in patients visiting the Radiology Department of The College of Dentistry in King Saud University between July 2018 and July 2019. The canal was examined if it was confluent with the distobuccal (DB) or distolingual (DL) canals, fin, or independent. Moreover, the distances from the MD canal to the DL and DB canals and cementoenamel junction (CEJ) were recorded.ResultsOne MD canal (0.7%) was observed in 145 teeth. It was confluent with the DL canal. No statistical significance was observed among sex and age. The distances from the MD canal to the DL canal, DB canal, and CEJ were 1.4 mm, 1.9 mm, and 3.1 mm, respectively.ConclusionsThe prevalence of the MD canal was significantly low in a Saudi subpopulation (0.7%). Careful evaluation of CBCT images and the pulpal floor is significantly important to detect the MD canal to ensure a good prognosis.     

The impact of salivary lactoperoxidase and histatin-5 on early childhood caries severity in relation to nutritional status

IntroductionEarly childhood caries is a multifactorial disease. Saliva plays an important role in initiation and protection against caries, and its composition is greatly affected by nutritional status. This study was conducted to determine the impact of salivary lactoperoxidase and histatin-5 on the severity of ECC in relation to nutritional status.Materials and methodsThe sample consisted of 120 children aged 5 years, classified into eight groups: mild ECC in underweight children, mild ECC in normalweight children, moderate ECC in underweight children, moderate in ECC normal weight children, severe ECC in underweight children, severe ECC in normalweight, caries-free (control) underweight children and caries-free normalweight children. Each group consisted of 15 children. Stimulated saliva was collected. Salivary lactoperoxidase was analysed using Human LPO/ Lactoperoxidase ELISA Kit (CLIA)-LS-F29892, and salivary histatin-5 was analysed using Human Histatin-5 ELISA Kit MBS705083_48T.ResultsLactoperoxidase and histatin-5 concentrations were significantly higher in caries-free children than in children with ECC, and they were higher in children with mild ECC than in children with moderate ECC or in children with severe ECC. They were significantly higher among children with normal weight than among those who were underweight (p < 0.01). ECC and nutritional status recorded non-significant interactions with both LPO and HST-5 (p > 0.01), but there was significant interaction between these two variables and LPO and HST-5 together (p < 0.01). The Pearson's correlation coefficient test recorded significant negative correlations between ECC severity and both salivary lactoperoxidase and histatin-5 among the eight study groups, whereas significant positive correlations were recorded between BMI values and both salivary lactoperoxidase and histatin-5 among the eight study groups.ConclusionSalivary lactoperoxidase and histatin-5 may be affected by nutritional status, and these two parameters may play an important role in caries prevention at high concentrations. There is interaction between these two parameters and ECC severity and nutrition.     

Remaining dentinal thickness after simulated post space preparation and the fit of prefabricated posts to root canal preparation shapes

BackgroundPost space preparation can increase the risk of experiencing perforation and root fracture. The authors assessed remaining dentin thickness after post space preparation and the fit of different prefabricated posts to root canal preparation systems in a theoretical model.MethodsTen datasets per type of tooth from cone-beam computed tomography were analyzed to determine the minimum root diameter from 5 through 13 mm from the apical foramen. The preparation shapes of 10 root canal preparation systems were calculated and compared with the root dimensions to determine the remaining dentin thickness. Eight post brands were compared with root dimensions to determine the areas where there was less than 1 mm dentin thickness.ResultsThe average root canal preparation shape produced canal diameters of 0.57 mm at 5 mm from the canal terminus and 0.94 mm at 13 mm from the canal terminus. The mean post size tip diameter was 1.03 mm, which is larger than the dimensions of the average canal preparation. Post preparation would result in less than 1 mm of dentin thickness remaining in premolars, smaller roots of molars, and mandibular incisors. The area with less than 1 mm of dentin thickness was around the post tip.ConclusionsEndosequence Fiber Post (Brasseler USA), RelyX Fiber Post 3D (3M), and Rebilda (VOCO) were the better fitting posts with the root canal preparation shapes.Practical ImplicationsMany posts would result in less than 1 mm dentin thickness. Clinicians should use posts that fit their root canal preparations to minimize dentin removal.     

A Study to assess the awareness and use of Silver Diammine Fluoride and Hall Technique among dental professionals and dental students in the Eastern Province

BackgroundA major shift has occured in the trend of dealing with dental caries from primary to secondary prevention, specially after SDF approval off-label by US FDA in recent years and Hall Technique (HT) in the last decade.ObjectivesTo determine the frequency of awareness and use of Silver Diammine Fluoride (SDF) and Hall technique among dental professionals in the Eastern province of Saudi Arabia.MethodsThis cross-sectional study was conducted in a public hospital, metropolitan city of Middle Eastern region between March 15, 2019 & January 31, 2020. Dental practitioners were requested, with their consent, to fill up a digitally designed survey. Chi-square test on SPSS-20.0 was applied to compare frequency of awareness and use of SDF and HALL Technique among the survey participants.ResultsThe awareness of SDF was found to be 73.6% among specialists, 54.9% among graduates and 29.6% among students whereas awareness of HALL technique for stainless steel crown in pediatric dentistry was found statistically similar in all participants groups i.e. 42.7% in students, 55.5% in graduates and 54.9% in specialist group (p = 0.125).ConclusionThe results show potential with regards to awareness of dental specialists & postgraduate residents but inadequate among general dentists and students though all were keen advocates and found committed to its use to help the community. It points towards a further need of the of education for all groups. Those non- invasive techniques are very useful tools in general but specifically during Covid-19 pandemic where they can play a major role in preventing the spread of infection, arresting decay, alleviating pain and anxiety without resorting to aggressive treatment like pulp treatment/extraction. Low response rate may be improved in future through the respondents’ counselling and regular follow up.     

An in vitro study of the effects of Phellodendron bark extract and berberine chloride on periodontal pathogenic bacteria in the oral microbiome

ObjectivesPeriodontal disease is triggered by oral microbiome dysbiosis. Thus, to prevent its onset, it is important to maintain relative abundance of periodontal pathogenic bacteria in the oral microbiome at a low level. While Phellodendron bark extract (PBE) and its active ingredient, berberine, exert antibacterial effects on periodontal pathogenic bacteria, such as Porphyromonas gingivalis, their effects on the oral microbiome as a whole remain unknown. Therefore, we aimed to clarify the potential of PBE and berberine chloride (BC) in regulating the relative abundance of periodontal pathogenic bacteria in the oral microbiome.MethodsSaliva was collected from 20 participants. Each participant's saliva was combined separately with P. gingivalis suspension and either PBE or BC in a modified basal medium. The samples were then incubated under anaerobic conditions for 24 h. After cultivation, we determined the total bacterial concentration using quantitative polymerase chain reaction analysis and the bacterial composition using 16 S ribosomal RNA gene sequencing.ResultsThe total bacterial concentration was reduced because of treatment with PBE and BC. Bacterial 16 S ribosomal RNA gene sequencing confirmed that treatment with PBE and BC significantly reduced the relative abundance of periodontal pathogenic bacteria, including red and orange complex bacteria.ConclusionsOur findings suggest that PBE and BC reduce the relative abundance of periodontal pathogenic bacteria in the oral microbiome. Thus, PBE and BC can aid in preventing periodontal disease, given their ability to regulate the oral microbiome composition and their anti-inflammatory effects.     

Biochemical and X-ray micro-computed tomographic analyses of critical size bone defects grafted with autogenous bone and mercerized bacterial cellulose membranes salified with alendronate

ObjectivesThis study aimed to evaluate the repair of critical-sized bone defects grafted with autogenous bone and mercerized bacterial cellulose membranes (BCm) salified with alendronate (ALN).MethodsForty-eight male Wistar rats underwent surgery to create a 5 mm-diameter bone defect in the calvarium. The removed bone was particularized, regrafted into the defect, and covered by a BCm according to the group: control group (CG), simply mercerized BCm; group 1 (G1), negatively charged BCm (BCm-CM^-) salified with ALN; and group 2 (G2), positively charged BCm (BCm-DEAE⁺) salified with ALN. Serum samples were collected preoperatively and before euthanasia to analyze osteoprotegerin (OPG), parathyroid hormone (PTH), sclerostin (SOST), and fibroblast growth factor 23 (FGF23) levels. The animals were euthanized after 15 or 60 d. Calvaria were analyzed using quantitative microtomography (μCT).ResultsThere was an increased level of PTH in the CG compared to the G2 group, at day 60 (p = 0.019). When analyzing the same group over time, G1 presented an increased FGF23 level on days 15 and 60 (p < 0.05). CG presented an increase in PTH (p = 0.037) at day 60. The μCT analysis detected increased trabecular separation on day 15 in G2 compared to G1 (p = 0.040).ConclusionsSalification of ionized BCm with ALN had no direct effect on bone repair; however, BCm-CM^- increased the levels of FGF23 over time. BCm-DEAE⁺ decreased PTH levels compared to mercerized BCm. BCm-CM-salified with ALN-induced superior bone quality, with respect to trabecular separation, compared to BCm-DEAE⁺.     

Correlation of plasma osteopontin and osteocalcin with lower renal function in dental patients with carotid artery calcification and tooth loss

ObjectivesTo investigate plasma osteopontin (OPN) and osteocalcin (OCN) levels in dental patients with carotid artery calcification (CAC) and determine the correlations between these proteins and renal function and tooth loss.MethodsThe health parameters and number of teeth of 99 participants were recorded. Panoramic radiographs were taken for CAC evaluation, and OPN and OCN levels were measured.ResultsNone of the participants had overt kidney disease, and 14 (14.14%) had CAC. The age, sex, and health profiles of patients with CAC were not different from those without CAC. The OPN and OCN levels in participants with CAC were higher than in those without (p = 0.026 and p = 0.025, respectively). The OPN levels were correlated with the estimated glomerular filtration rate (eGFR) (p = 0.021) and tooth loss (p = 0.027). The OCN levels were correlated with the eGFR (p = 0.002), tooth loss (p = 0.023), blood urea nitrogen (p = 0.040), and creatinine levels (p = 0.031). The median tooth loss in individuals with an eGFR <60 mL/min/1.73 m² was higher than that of individuals with an eGFR ≥60 mL/min/1.73 m² (p = 0.033). In individuals with CAC, tooth loss correlated more strongly with the eGFR, and the correlation between OPN and OCN levels was more apparent.ConclusionDental patients with CAC and increased tooth loss have a greater tendency for decreased renal function, which may be associated with OPN and OCN; thus, these patients should be referred for investigation.     

Comparison of the abrasive effects of children's toothpaste on glass ionomer cement

ObjectivesTo evaluate the effect of two different children's toothpaste on the surface properties of conventional glass ionomer cement (GIC), which is used in Atraumatic Restorative Treatment (ART) method.MethodsThere were 3 groups and 10 glass ionomer cements in each group. The distribution was as follows: Group 1, Splat; Group 2, R.O.C.S.; Group 3, Control. A test aparatus made of steel with a screw design that allows the replacement of electric toothbrushes was designed to provide 2 N force. Brushing was carried out for each samples for duration of 2 min, twice a day, for seven days. One-way ANOVA for intergroup comparison and paired sample T tests for intragroup comparisons were used in statistical analysis, the significance level was p < 0.05.ResultsAccording to the results, no statistically significant difference was found between the baseline and 7th day roughness values within and between groups (p > 0.05). Although not statistically significant, as a percental increase in roughness was found in each group compared to the initial values. This amount of increase was found in Group 2, Group 1 and Group 3 as a descending order. The results were supported by scanning electron microscopy analysis.ConclusionAs a result of this study, child pastes that do not cause a statistically significant increase in roughness were found to be safe for daily use. When considering long-lasting restorations, low relative dentin abrasivity (RDA) value child pastes can be recommended as they will encourage brushing with both taste and smell compared to brushing with water.     

Characterization of silver diamine fluoride cytotoxicity using microfluidic tooth-on-a-chip and gingival equivalents

ObjectiveThis study aims to characterize the cytotoxicity potential of silver diamine fluoride (SDF) on dental pulp stem cells (DPSC) and gingival equivalents.MethodsDPSC cultured on 96-well plates was exposed directly to SDF (0.0001–0.01%) and cell viability (IC₅₀) quantified. Effect of SDF on DPSC viability under flow (with dentin barrier) conditions was evaluated using a custom-designed microfluidic "tooth-on-a-chip”. Permeability of dentin discs (0.5–1.5 mm thickness) was evaluated using lucifer yellow permeation assay. Dentin discs were treated with 38% SDF (up to 3 h), and cell viability (live/dead assay) of the DPSC cultured in the inlet (unexposed) and outlet (exposed) regions of the pulp channel was evaluated. To assess the mucosal corrosion potential, gingival equivalents were treated with 38% SDF for 3 or 60 min (OECD test guideline 431) and characterized by MTT assay and histomorphometric analysis.ResultsDPSC exposed directly to SDF showed a dose-dependent reduction in cell viability (IC₅₀: 0.001%). Inlet channels (internal control) of the tooth-on-a-chip exposed to PBS and SDF-exposed dentin discs showed> 85% DPSC viability. In contrast, the outlet channels of SDF-exposed dentin discs showed a decreased viability of< 31% and 0% (1.5 and ≤1.0 mm thick dentin disc, respectively) (p < 0.01). The gingiva equivalents treated with SDF for 3 and 60 min demonstrated decreased epithelial integrity, loss of intercellular cohesion and corneal layer detachment with significant reduction in intact epithelial thickness (p < 0.05).SignificanceSDF penetrated the dentin (≤1 mm thick) inducing significant death of the pulp cells. SDF also disrupted gingival epithelial integrity resulting in mucosal corrosion.     

Conditioned-medium of stem cells from human exfoliated deciduous teeth prevent apoptosis of neural progenitors

PurposeThis study aimed to evaluate the neuroprotective ability of the conditioned medium of stem cells from human exfoliated deciduous teeth (CM-SHED) to prevent glutamate-induced apoptosis of neural progenitors.Materials and methodsNeural progenitors were isolated from two-day-old rat brains, and the conditioned medium was obtained from a mesenchymal stem cell SHED. Four groups were examined: neural progenitor cells cultured in neurobasal medium with (N + ) and without (N-) glutamate and glycine, and neural progenitor cells cultured in CM-SHED with (K + ) and without (K-) glutamate and glycine.ResultsThe expression of GABA A1 receptor (GABAAR1) messenger RNA (mRNA) in neural progenitor measured by real-time quantitative PCR. GABA contents were measured by enzyme-linked immunosorbent assay, whereas the apoptosis markers caspase-3 and 7-aminoactinomycin D were analysed with a Muse® cell analyzer. The viability of neural progenitor cells in the K + group (78.05 %) was higher than the control group N- (73.22 %) and lower in the N + group (68.90 %) than in the control group. The K + group showed the highest GABA content, which significantly differed from that in the other groups, whereas the lowest content was observed in the N + group. The expression level of GABAAR1 mRNA in the K + group was the highest compared to that in the other groups. CM-SHED potently protected the neural progenitors from apoptosis.ConclusionsCM-SHED may effectively prevent glutamate-induced apoptosis of neural progenitors.