One case of complicated crown root fracture of upper anterior teeth managed by multidisciplinary joint approaches.

Complicated crown root fracture is a serious combined fracture of the enamel, dentin, and cementum in dental trauma. The treatment method is complicated. During the procedure, the condition of pulp, periodontal, and tooth body should be thoroughly evaluated, and a multidisciplinary approach combined with sequential treatment is recommended. This case reported the different treatment and repair processes of one case of two affected teeth after complicated crown root fracture of upper anterior teeth, including regrafting of broken crown after flap surgery at the first visit, direct resin repair to remove broken fragments, and pulp treatment and post-crown repair at the second visit. After 18 months of follow-up, the preservation treatment of the affected teeth with complicated crown root fracture was achieved. Therefore, fragment reattachment and post-crown restoration are feasible treatment options for children with complicated crown root fracture.

Success rate of the treatment of early childhood caries under general anesthesia: A retrospective cohort study in different periods.

Instruction: The purpose of this study was to evaluate the three-year success rate of the treatment for early childhood caries (ECC) under general anesthesia in different periods (2011 and 2018). Methods: Children (<6 years old) who had severe caries and were treated under general anesthesia in 2011 and 2018 were selected and followed up by telephone appointment and clinical examination. Success rate of each treatment was determined and possible factors associated with treatment failure were evaluated. Results: There were 153 patients (with an average age of 48.55 ± 13.37 months) and a total of 2,018 teeth included in the 2011 group. In the 2018 group, there were 273 patients with an average age of 49.01 ± 12.42 months and a total of 3,796 teeth. The success rate in the 2011 group was significantly lower than that in the 2018 group. Teeth with mineral trioxide aggregate (MTA)-capped pulp survived significantly longer than those with calcium hydroxide-capped pulp. The utilization rate of preformed crown restoration was higher than that of resin restoration, and the survival time of dental restorations with preformed crown was prolonged. For posterior teeth, the success rate of indirect pulp capping and pulpotomy was also significantly higher than those without preformed crowns. Discussion: General anesthesia is a safe and effective behavioral management method for uncooperative children's dental treatment. The use of biocompatible pulp capping materials and preformed crowns improved the success rate of treatment and prolonged the survival time of affected teeth.

Measurement of the morphological data of primary teeth in northwest China.

Objective: This study aims to digitally obtain the morphological data of children's primary teeth in northwest China and evaluate the reliability of digitally obtaining the anatomical morphological data of primary teeth. Methods: A total of 308 extracted primary teeth and cone-beam computed tomography (CBCT) images of 407 primary teeth were collected in northwest China. Electronic digital Vernier callipers (accuracy: 0.01 mm) were used to measure the mesiodistal and buccolingual diameters and crown length of the extracted primary teeth and calculate the crown area and crown index. Each sample was scanned with an intraoral scanner (Trios2 3shape, Denmark), and the resulting stl format files were imported into Geomagic Wrap 2015 to measure the axial and buccolingual diameters and crown length. The crown area and crown index were then calculated. After verifying the accuracy of the CBCT image measurement, the CBCT image data of 407 samples were measured in SmartV software using the "measure length" function by referring to the coronal, sagittal, and horizontal planes to adjust the position of the reference line. Results: Northern Chinese have larger primary teeth than other populations (Japanese, white American, African, Icelander, Spanish, and Dominican Mestizo) but smaller primary teeth than native Australians. Compared to Indian primary teeth, northwest Chinese's primary teeth have larger diameters on the central axis and smaller diameters on the buccolingual surface. Male teeth are usually larger than female teeth. Compared with the results of Wang Huiyun's study, the axial and buccolingual diameters and crown length of all native tooth types in this total sample were significantly smaller at the 0.1% level, and only the axial diameters of the upper first molar and lower second molar and the crown length of the lower lateral incisor were significantly smaller at the 1% level. The results of the intraclass correlation coefficient of 308 extracted primary teeth expressed an excellent degree of agreement between the callipers and intraoral scanner for the following: mesiodistal diameter (0.956-0.991), buccolingual diameter (0.963-0.989), crown length [0.864-0.992, except for the upper canine (0.690)], crown index (0.850-0.975), and crown area (0.946-0.993). Conclusion: The digital measurements of the intraoral scanner and CBCT image are in good agreement with the manual measurement of the Vernier calliper. The difference between the anatomical morphology size of the primary teeth measured in this study and the results of different populations could be due to different genetic backgrounds and environmental factors.

Clinical efficacy of Er:YAG laser application in pulpotomy of primary molars: a 2-year follow-up study.

The present study aimed to analyze the clinical effects of Er:YAG laser applied in pulpotomy of children's asymptomatic deep caries-affected primary molars. Included primary molar teeth from children (aged 3 ~ 6 years) were randomly assigned to "Er:YAG laser" and "conventional" groups, and pulpotomies were performed under general anesthesia using the respective approaches. The treatment time and clinical efficacy were evaluated. The study sample included 100 primary molar teeth of 40 children with an average age of 4.60 ± 1.02 years. The pulpotomy time in the Er:YAG laser group was significantly longer than that in the conventional group (p < 0.0001) but the hemostasis time and the total treatment time were significantly shorter (p < 0.0001, p = 0.029). In terms of clinical efficacy, up to 6 months after treatment, the success rate in the Er:YAG laser group was non-significantly but slightly higher than that in the conventional group (100% versus 98%, p = 0.436). With longer observation time, the success rate of both groups declined, with the conventional group showing a more rapid decline. After 24 months, the success rate in the Er:YAG laser group remained non-significantly higher than that in the conventional group (89.58% versus 82.98%, p = 0.386). Overall, Er:YAG laser significantly reduced the treatment time for pulpotomy in primary teeth and tended to produce higher clinical efficacy over time and thus can be a valuable tool in clinical pediatric dentistry practice.

A comparison of the mechanical proprieties of different types of primary tooth restorations: an in vitro study.

OBJECTIVE: To compare the different restoration types of primary teeth to determine which type is appropriate for extensive caries of primary molars and incisors based on mechanical properties. MATERIALS AND METHODS: A total of 160 primary teeth were evaluated in this study, including 80 incisors and 80 molars. Each category was divided into four groups: the control group, composite resin group, pre-veneered stainless steel crown (stainless steel crown) group, and zirconia crown group. Compressive strength test and fatigue strength test were performed. RESULTS: The compressive strength and fatigue strength of the composite resin group were significantly decreased compared with the control group (P < 0.05). The prefabricated crown groups showed increased fatigue and compressive strength compared with the control group, and the zirconia crown group was higher than that of the pre-veneered stainless steel crown group (P < 0.05). The zirconia crown group was less than the stainless steel crown group (P < 0.05) in the compressive strength but more than the stainless steel crown group (P < 0.05) in the fatigue strength. CONCLUSIONS: The compressive strength and fatigue strength of crown restoration were superior to that of the composite resin filling. The fatigue strength of the zirconia crown also performed better than the pre-veneered stainless steel crown and the stainless steel crown. The compressive strength of the zirconia crown was less than that of the stainless steel crown. CLINICAL RELEVANCE: The zirconia crown is a new restoration method for primary teeth that may be commonly applied in clinical practice.

Treatment of a Young Maxillary Central Incisor with Two Root Canals: A Case Report.

Currently, the common treatment for pulpitis and periapical diseases is root canal treatment. However, the complex variations of root canal system often affect the effect of root canal treatment and even lead to treatment failure. Therefore, it is of great significance for dentists to emphasize the diversity of root canal morphology and to be familiar with the anatomical morphology of root canal to improve the success rate of clinical diagnosis and treatment. We reported a case of an eight-year-old female patient of type V root canal in a young maxillary middle incisor. The young maxillary central incisor was diagnosed with irreversible pulpitis by radiography and CBCT examination. The present case report described the entire treatment procedure of a young maxillary central incisor after trauma, including successive apical examination, CBCT examination and multiple root canal filling, and finally the treatment was completed with the aid of microscope. The root canals were filled with the vertical compression technique. Z350 composite resin was used to repair the tooth. The patient was followed-up at three, six, and 12 months after endodontic treatment. All of the examinations were normal. Finding the anatomical configuration of root canal by various ways will help to improve the success rate of root canal therapy.