Objectives: This study aims to evaluate the efficacy of the rotary instrument XP-endo Finisher for the removal of Ca(OH)₂ aided by different irrigation regimens. Methods: Sixteen double-rooted upper premolar human teeth were selected for the study. Thirty-two canals were prepared using a ProTaper Next rotary system up to X3. Then, the canals were filled with Ca(OH)₂. The volume of Ca(OH)₂ inside the canals was measured by microcomputed tomography (micro-CT). After that, the teeth were randomly allocated into two experimental groups, i.e., A and B (n = 16 canals). In group A, Ca(OH)₂ was removed using the master apical file (X3). In group B, Ca(OH)₂ was removed using a XP-endo finisher. In half of both groups (n = 8), syringe irrigation (SI) was used, while passive ultrasonic irrigation (PUI) was used for the other half. After removal, the remaining volume of Ca(OH)₂ was measured. All data were statistically analyzed using two-way ANOVA with Tukey’s post hoc test. Results: The percentages of remaining Ca(OH)₂ in the apical thirds of all canals were significantly higher as compared with the middle and coronal thirds in all groups (p < 0.05). There was no significant difference between different files and techniques (p > 0.05). Clinical Significance: This study presents a new method for the removal of Ca(OH)₂ from root canals.

The action of stem cells is mediated by their paracrine secretions which comprise the secretory profile. Various approaches can be used to modify the secretory profile of stem cells. Creating a hypoxic environment is one method. The present study aims to demonstrate the influence of CoCl₂ in generating hypoxic conditions in a dental pulp stem cell (DPSCs) culture, and the effect of this environment on their secretory profile. DPSCs that were isolated from human permanent teeth were characterized and treated with different concentrations of CoCl₂ to assess their viability by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and proliferation by a cell counting kit (CCK)-8 assay. The gene expression level of hypoxia-inducible factor 1-alpha (HIF-1α) was analyzed by quantitative real time polymerase chain reaction (qRT-PCR) to demonstrate a hypoxic environment. Comparative evaluation of the growth factors and cytokines were done by cytometric bead array. Gene expression levels of transcription factors OCT4 and SOX2 were analyzed by qRT-PCR to understand the effect of CoCl₂ on stemness in DPSCs. DPSCs were positive for MSC-specific markers. Doses of CoCl_2, up to 20 µM, did not negatively affect cell viability; in low doses (5 µM), it promoted cell survival. Treatment with 10 µM of CoCl₂ significantly augmented the genetic expression of HIF-1α. Cells treated with 10 µM of CoCl₂ showed changes in the levels of growth factors and cytokines produced. It was very evident that CoCl₂ also increased the expression of OCT4 and SOX2, which is the modulation of stemness of DPSCs. A CoCl₂ treatment-induced hypoxic environment modulates the secretory profile of DPSCs.

BACKGROUND: The occurrence of periodontitis is rather infrequent in children and adolescence and increases with age. We conducted this study because there have been few epidemiological studies on prevalence of periodontitis in children in Saudi Arabia.OBJECTIVE: Determine the prevalence of periodontitis in high school children in Saudi Arabia.DESIGN: Cross-sectional, using cluster and multistage sampling.SETTING: High school children in Saudi Arabia.PARTICIPANTS AND METHODS: Periodontal examinations were conducted on a randomized sample of high school children between the ages 15 to 19 in Saudi Arabia. The study spanned from September 2012 to January 2016. Clinical examinations included measurements of the probing depth (PD) percentage of PD ≥4 mm per patient.MAIN OUTCOME MEASURES: The prevalence of periodontitis (PD ≥4 mm and CAL ≥1 mm), the mean percentage PD ≥4 mm, the mean percentage CAL ≥1 mm, plaque index (PI) and gingival index (GI).SAMPLE SIZE: 2435 high school students.RESULTS: Of 2435 high school children in the sample, 209 students (8.6%) had periodontitis. The mean (standard deviation) for the PD was 0.59 (0.17) mm. Differences in percentage PD ≥4 mm and CAL ≥1 mm were greater in students with periodontitis (P<.001). The prevalence of periodontitis was higher among non-Saudis, students who did not brush their teeth and did not visit their dentist regularly. In the bivariate analysis, periodontitis was positively associated with GI, PI, number of teeth extracted, mean percentage PD ≥4 mm, and mean PD. However, in the multivariate analysis, tooth brushing was the main factor protective against periodontitis (odds ratio: 0.62, 95% CI 0.42-0.92,P=.017).CONCLUSION: Periodontitis prevalence was high compared with Western countries in a nationally representative sample of high school students in Saudi Arabia.LIMITATIONS: Partial mouth study design, which may underestimate the disease prevalence.CONFLICT OF INTEREST: None.

Background: The study aims to investigate the pulp and periapical reaction and healing after capping with EndoSequence Root Repair Material (ERRM) combined with low-level laser application.Methods: In 6 rabbits, pulps were exposed via class V, half of the samples received a low-level diode laser at 980 nm. Thereafter, cavities were capped with regular-set ERRM. The specimens were processed for histomorphological examination after 2 weeks and two months.Results: After 2 weeks, images show mild inflammation and organized odontoblasts in lased group. The non-lased group shows more severe inflammation. The predentin thickness was thicker in the lased group with statistical significance (p < 0.05). After 2 months, inflammatory cells were sparse in both lased and non-lased groups. In the periapical area, group one showed dilated blood vessels and thick fibrous connective tissues. In group two, there were more numerous maturations of PDL fibers with scattered inflammatory cells and congested blood vessel.Conclusions: Using low-level laser therapy in combination with ERRM for pulp capping shortens the inflammatory phase and enhances healing.

Background: One of the main reasons for post endodontic pain is the polymicrobial intracanal flora that may survive the initial disinfection. A single antimicrobial agent might not provide adequate disinfection, and an antimicrobial combination such as triple antibiotic paste was tested to achieve this goal. Aim: The study aimed to assess the efficacy of three intra-canal medicaments on post root canal preparation pain. Materials and Methods: Eighty patients with single-rooted necrotic teeth and symptomatic apical periodontitis were randomly assigned to four treatment groups (n = 20). Their preoperative pain was recorded on Wong-Baker’s FACES pain rating scale. After chemo-mechanical canal preparation, intracanal medications were applied to the groups (Group 1 (20% calcium hydroxide), Group 2 (2% chlorhexidine), Group 3 (tri-antibiotic paste), Group 4 (no medication (Control group)). Patients were instructed to record pain on the Wong-Baker FACES pain rating scale at 4, 48, 72 and 96 hrs, postoperatively. Pain scores were analyzed using a one-way ANOVA test and Tukey’s post hoc test and, if significant, Dunn’s test was used for pair-wise comparisons. The significance level was set at a p-value ≤ 0.05. Results: Tukey’s post hoc test revealed significantly lower pain scores in Group 3 compared with other groups at all follow up intervals. Dunnett’s test showed significantly lower pain in Group 3 compared with the Control group at 48, 72 and 96 hrs, postoperatively. Conclusions: Triple-antibiotic paste showed effective pain control as an intracanal medication on necrotic teeth with symptomatic apical periodontitis.