METHODS: A literature search was performed in 3 electronic databases for articles published before August 2018. Randomized clinical trials published in English that compared PP between machine-assisted agitation and syringe irrigation with needles as part of nonsurgical root canal treatment were included. Two authors were independently involved in the article selection process, data extraction, and assessment of the quality of included studies using the revised Cochrane risk of bias tool. The pooled effect estimates of the standardized mean difference (SMD) between machine-assisted agitation and syringe irrigation with needle was calculated by a random effects-modeled meta-analysis. A subgroup meta-analysis was performed. The quality of evidence was evaluated by the Grading of Recommendations, Assessment, Development and Evaluations approach.

RESULTS: Six studies were included for systematic review. Meta-analysis was performed using 3 studies and showed that machine-assisted agitation resulted in less PP compared with syringe irrigation with needle at 24 hours (SMD = -0.73; 95% confidence interval, -1.04 to -0.42; I2 = 30.6%) and 48 hours (SMD = -0.60; 95% CI, -0.85 to -0.35; I2 = 0%). The quality of evidence by Grading of Recommendations, Assessment, Development and Evaluations for the PP outcomes (24 hours and 48 hours) was graded as "moderate" quality.

METHODS: Electronic searches were performed in Web of Science, PubMed, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Cochrane Library databases. Two authors independently screened the titles and abstracts for eligibility. The analyses were performed on the clinical outcomes (ie, survival, healing, and root development) of the procedure.

RESULTS: Eleven articles were included in the qualitative and quantitative syntheses. Three studies were randomized controlled trials, 6 were prospective cohort studies, and 2 were retrospective cohort studies. The pooled survival and healing rates were 97.3% and 93.0%, respectively. The pooled rates of root lengthening, root thickening, and apical closure were 77.3%, 90.6%, and 79.1%, respectively. However, if 20% radiographic changes were used as a cutoff point, there were only 16.1% root lengthening and 39.8% root thickening.

METHODS: Fifty-six mature necrotic teeth with large periapical radiolucencies were distributed into 2 groups: group 1, REPs and group 2, CRCT (n = 28/group). Clinical and radiographic follow-up assessments were undertaken up to 12 months. Statistical analysis was performed using the independent samples t test and the chi-square test, and the level of significance was set at P = .05.

RESULTS: With a follow-up rate of about 73.4% of the total patients for 12 months, favorable clinical and radiographic outcomes were found in 92.3% and 80% in REPs and CRCT groups, respectively, and the difference was not statistically significant (P > .05). Half of the teeth treated with REPs responded to the electric pulp test.

METHODS: A review of clinical cases reporting NaOCl accidents was conducted in June 2016 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist; it combined an electronic search of the PubMed database and an extensive manual search.

RESULTS: Forty full-text articles corresponding to 52 case reports published between 1974 and 2015 were selected. Four main categories of data were highlighted: general and clinical information, clinical signs and symptoms of NaOCl extrusions, management of NaOCl extrusions, and healing and prognosis. Overall, up to now, clinical cases were reported in a very unsystematic manner, and some relevant information was missing.

METHODS: Observers from 44 countries screened 13,200 canines using cone-beam computed tomographic exams and gather data on the percentages of 2 root canal morphologies and 2-rooted configurations (primary outcomes), as well as the root canal configurations (secondary outcome). Demographic factors (ethnicity, sex, and age) were collected for each participant. Primary outcomes were represented as odds ratios and untransformed proportions accompanied by 95% confidence interval (CI) forest plots. Meta-analysis compared sub-groups and identified sources of heterogeneity. Intra- and inter-rater tests were conducted. Statistical significance was set at 5%.

RESULTS: The worldwide prevalence of a second canal was 7.5% (95% CI, 6.3%-8.7%), ranging from 0.7% in Nigeria to 17.7% in Uruguay. The meta-analysis also revealed significant variations when comparing ethnicity, gender and age (P.05).

METHODS: 26,400 mandibular incisors were evaluated using cone-beam computed tomography imaging by pre-calibrated observers from 44 countries. A standardized screening method was employed to collect data on the presence of a lingual canal, the anatomic configuration of the root canal, and number of roots. Patient demographic information (age, sex, and ethnicity) was also recorded. Multiple intra- and inter-rater tests assessed the reliability of the observers and groups, and a meta-analysis was used to examine differences and heterogeneities (α=5%).

METHODS: Observers from 44 countries assessed 26,400 maxillary premolars using cone-beam computed tomography and employed a standardized screening method to gather data on multiple canal morphology and 3-rooted configuration (primary outcomes), as well as secondary outcomes related to root and root canal anatomies. Demographic factors such as ethnicity, sex, and age were collected for each participant. The intra- and inter-observer tests ensured observer reliability. Primary outcomes were represented as odds ratios and untransformed proportions accompanied by 95% confidence interval (CI) forest plots. Meta-analysis compared sub-groups and identified sources of heterogeneity (α=5%).

RESULTS: The overall prevalence of multiple canal morphology in the first premolar was 93.5% (95% CI, 93.3%-94.7%), while in the second premolar, it was 49.7% (95% CI, 44.9%-54.6%). The proportion of 3-rooted configuration was 1.8% (95% CI, 1.4%-2.1%) in the first premolar and 0.4% (95% CI, 0.3%-0.5%) in the second. Asian countries generally displayed fewer roots and root canals, while European nations showed higher counts (P<0.05). Males exhibited higher percentages and odds ratios for both outcomes in both premolars. Younger patients demonstrated lower percentages of multiple root canal morphologies (P<0.05). Factors such as tooth side, voxel size and field-of-view did not influence the outcomes (P>0.05).