ObjectiveTo investigate the root and canal morphology of permanent mandibular anterior teeth in a Chongqing population using cone-beam computed tomography (CBCT).MethodsCBCT images of 1,725 patients in a Chongqing population were selected, and a total of 9,646 mandibular anterior teeth were analyzed. The number of root canals and the canal configurations were investigated.ResultsIn total, 0.3% (11/3,257) of lateral incisors and 0.8% (26/3,014) of canines had double roots, and 3.8% (127/3,375) of central incisors, 10.6% (345/3,257) of lateral incisors, and 4.2% (127/3,014) of canines had multi-root canals. The difference in the incidence of multi-canals in lateral incisors between female and male was statistically significant. The frequency of multi-canals in the different age groups was 5.0% for central incisors for ages 21–30 years, 14.7% for lateral incisors for ages 41–50 years, and 8.1% for canines for ages 41–50 years.ConclusionWith the limitations of the current study, we found that a high percentage of mandibular anterior teeth had multiple canals in the studied Chinese Chongqing population. The current data may provide clinicians practicing in Chongqing with a more thorough understanding of root canal morphology.

ObjectiveTo estimate the effect of arginine-containing desensitizing toothpaste on dentin hypersensitivity (DH).MethodsDatabases including China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals, China Biology Medicine disc, Wangfang Data, PubMed, Web of Science, and Cochrane Trials Register were searched, and Google was used as a supplementary tool to search for information through February 2014. Randomized controlled trials (RCTs) of the treatment of DH with arginine-containing toothpaste were included. Relevant information was extracted, and a quality evaluation was performed. Meta-analyses were performed using RevMan 5.2 software.ResultsEighteen RCTs with 1,423 patients were included. The results of the meta-analyses demonstrated that at days 0 and 3; weeks 2, 4, and 8; and more than 12 weeks, arginine-containing toothpaste led to significantly improved results on the tactile sensitivity test (standardized mean difference [SMD] =1.95, 95% confidence interval [CI] [1.14, 2.76]) and the air-blast test (SMD =−1.60, 95% CI [−2.14, −1.05]) at 4 weeks and the tactile sensitivity test (SMD =2.01, 95% CI [1.41, 2.61]) and the air-blast test (SMD =−1.41, 95% CI [−1.83, −0.98]) at 8 weeks compared to toothpastes containing other desensitizing components, thus indicating a superior therapeutic effect of arginine-containing desensitizing toothpaste. However, no significant differences between arginine-containing toothpaste and toothpastes containing other desensitizing components were observed in the air-blast test at days 0 and 3 and week 2 and in the tactile sensitivity and air-blast tests at more than 12 weeks.ConclusionThe current evidence indicates that arginine-containing toothpaste is effective for DH. However, further high-quality, large-sample RCTs are needed.

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