Accuracy of the American Association of Endodontists diagnostic criteria for assessing pulp health in primary teeth

OBJECTIVES

There is a lack of studies evaluating the accuracy of the 2009 American Association of Endodontists (AAE) diagnostic criteria for diagnosing pulpal health in primary teeth. This study aimed to estimate and correlate the diagnostic accuracy of clinical diagnosis of reversible and irreversible pulpitis using the 2009 AAE criteria with histological findings in primary teeth.

METHODS

Eighty primary teeth that were clinically diagnosed with normal pulp (n = 10), reversible pulpitis (n = 30), irreversible pulpitis (n = 30) and pulp necrosis (n = 10) were collected. The teeth were histo-processed, and pulp tissues were diagnosed histologically as uninflamed pulp, reversible or irreversibly inflamed and necrosis based on previously proposed criteria.

RESULTS

The clinical diagnosis of pulp necrosis (sensitivity 70%, specificity 96%) and normal pulp (sensitivity 91%, specificity 100%) matched the histological diagnosis of necrosis and uninflamed pulp in 70% and 100%, respectively. The clinical diagnosis of irreversible pulpitis (sensitivity 64%, specificity 72%) matched the histological diagnosis of irreversible pulp inflammation for 47% of teeth evaluated. For the clinical diagnosis of reversible pulpitis (sensitivity: 65%, specificity: 86%), 80% matched the histological diagnosis of reversible pulp inflammation. Teeth with histologically diagnosed irreversible pulp inflammation were more likely to have lingering (OR 5.08; 95% CI 1.48-17.46, P = 0.010) and nocturnal tooth pain (OR 15.86; 95% CI 1.57-160.47, P = 0.019) when compared to teeth with reversible pulp inflammation. Using the classification and regression tree model, the presence of widened periodontal ligament space and nocturnal tooth pain were useful predictors of irreversible pulp inflammation with an accuracy of 78%.

CONCLUSION

The 2009 AAE criteria was acceptable for primary teeth with pulp necrosis and normal pulp but poor for reversible pulpitis and irreversible pulpitis.

Society of Pediatric Dentistry. [Guideline on operation of stainless steel crown for decidous teeth restoration]

Deciduous caries and abnormal tooth development are common children's oral diseases which seriously harm the health of deciduous dentition, hinder the absorption of nutrients and affect the general growth and development. Caries of deciduous teeth progresses rapidly and can develop into rampant caries and other hard tissue diseases in a short time. The metal prefabricated crown is a stainless steel restoration for the treatment and repair of severe dental tissue damage in children. Its repair technique has certain operating procedures, requires specific equipments and materials, needs qualified dental clinicians to complete. The Society of Pediatric Dentistry, Chinese Stomatological Association organized experts to formulate the guideline of the clinical operation stainless steel crown restoration, so as to standardize the application of stainless steel crowns in the molar repair treatment of deciduous teeth such as caries in children and to further promote the application of the technique.

[The pattern and regulatory mechanism of mammalian diphyodont tooth replacement]

Although the dental lamina of permanent teeth in human being has been developed as early as the embryo stage, the replacement of the deciduous teeth by permanent teeth does not take place untill the age of 6 to 12 years old. The molecular mechanism of the initiation of permanent teeth is still unclear. The rodent species are usually used for the tooth development research in the past. However, this animal model is not suitable for the tooth replacement study because of the absence of tooth replacement in rodents. After 10 years of efforts, our team has established the animal model of miniature pig for tooth replacement research. Using this model, we firstly defined the spatiotemporal pattern of teeth replacement. In the further mechanism research, results showed that the growing rate of the deciduous teeth was faster than that of the surrounding alveolar bone, and biomechanical stress inside mandible was generated due to the fast growth of deciduous teeth. The stress might up-regulate the signal of Runt-related transcription factor 2 (RUNX2)-Wnt pathway in the mesenchyme between the deciduous and permanent teeth, sustain the successional dental lamina at the resting stage and inhibit the development of permanent teeth. A similar expression pattern was also found in the mesenchyme between the deciduous and permanent teeth in human. Our findings demonstrated that the eruption of deciduous tooth released the stress inside mandible, thus induced the "Wnt translocation" from the mesenchyme into the epithelium of permanent counterpart and therefore initiated the development of permanent teeth. The underlying mechanism of the replacement of deciduous teeth by permanent teeth is the regulation of biomechanical stress throughout the initiation process. Based on the findings, we proposed the theory of "biomechanical stress regulation of the tooth replacement" . The replacement pattern and regulatory mechanism provide a scientific foundation for the organ development and regeneration by regulating the biomechanical stress and Wnt pathway in the future.

[Space maintenance for the premature loss of the second primary molar]

Space reduction after the premature loss of the second primary molars is one of the important factors affecting the occurrence of malocclusion, often increasing the demand for orthodontic treatment. It has great significance to select and apply appropriate appliances to maintainthe space soon after the premature loss of the second primary molars. The space should be maintained until the adjacent teeth and the successors erupt successfully. This review summarizes the selection and clinical application of the space maintainer for the premature loss of the second primary molars in different periods, to improve dentists' awareness of the importance of space maintainers and to provide advises for clinical choices.

[Development of primary teeth among infants and toddlers in nine cities of China in 2015]

Objective: To investigate the status of the development of primary teeth and to identify the development patterns among infants and toddlers in nine cities of China in 2015. Methods: Healthy children aged 1-<36 months were investigated by across-sectional survey and retrospective studies, which was carried out in 9 cities (Beijing, Harbin and Xi'an in northern China; Shanghai, Nanjing and Wuhan in central China; and Guangzhou, Fuzhou and Kunming in southern China) from June to October in 2015. Subjects (n=103 995) were divided into 14 age groups (1-<2, 2-<3, 3-<4, 4-<5, 5-<6, 6-<8, 8-<10, 10-<12, 12-<15, 15-<18, 18-<21, 21-<24, 24-<30, 30-<36 months). There were 150-200 boys and girls respectively in each group of urban and suburb areas in each city. The eruption status and the number of primary teeth were examined by the trained child health care physician or pediatrician on the spot. The timing of primary teeth eruption of children was retrospectively surveyed using a questionnaire. The prevalence of primary teeth was calculated and χ(2) test was used for comparison of categorical data. Probit regression analysis was used to determine the median and percentile age of eruption of primary teeth. Results: Totally 103 995 children aged 1-<36 months were investigated. There were 52 346 children in urban areas (boys 26 228, girls 26 118) and 51 649 children in suburb areas (boys 25 912, girls 25 737). The eruption rate of primary teeth in children under 2 years became higher with age and the difference among each age group was statistically significant (χ(2)=85 913.868, P<0.01), which was 0.3% (22/7 450) in 3-<4 months group, 43.0% (3 227/7 503) in 6-<8 months group and 99.9% (7 441/7 446) in 15-<18 months group. The eruption age of primary teeth was 6.6 months (95%CI: 6.5-6.7 months), and the range of the 3rd to 97th percentile was 4.1-10.6 months. The eruption ages of primary teeth in urban and suburb areas children were 6.6 months (95%CI: 6.5-6.7 months) and 6.6 months (95%CI: 6.5-6.7 months) respectively. The eruption age of primary teeth was earlier in boys (6.4 months, 95%CI: 6.3-6.5 months) than that in girls (6.7 months, 95%CI: 6.6-6.8 months). The median eruption age of primary teeth was earlier in northern China (6.2 months) than that in central (6.7 months) and southern China (6.9 months). The eruption rate of primary teeth became higher with age, showing that the median number of primary teeth was 2 in 8-<10 months group, 8 in 12-<15 months group and 20 in 30-<36 months group. Conclusions: The timing of eruption of primary teeth was similar between urban and suburb areas children and that of the boys was slightly earlier than that of the girls. There were slight differences among different regions in the eruption timing of primary teeth. The range of the 3rd to 97th percentile in the eruption age of primary teeth was 4.1-10.6 months and the number of primary teeth followed the regular development pattern with age.

[Analysis of dental caries and related factors in preschool children in Qingdao in 2018]

Dental caries are common diseases in children and often affect their growth and development. In order to understand the dental caries status of preschool children in Qingdao, a total of 1 690 children aged 3-6 years were screened from 13 kindergartens in two districts of Qingdao. The oral health examination was conducted according to the WHO standard, including the decayed-missing-filled index and pigmentation status. The prevalence of caries, the mean decayed, missing and filled tooth (dmft) and the mean dmfs were calculated. The results showed that the prevalence of deciduous teeth caries of children was 65.3% (n=1 103) with the mean dmft and dmfs about 3.2 and 5.4. There was a statistically significant difference in the prevalence of deciduous teeth caries among different age groups (P<0.001). There was a statistically significant difference between the prevalence of deciduous teeth caries with and without pigmentation (P<0.001). The prevalence of caries in preschool children in Qingdao is high and more attention should be paid to their dental caries.

Risk of Dental Caries in Primary Teeth with Developmental Defects of Enamel: A Longitudinal Study with a Multilevel Approach

The risk of dental caries seems to be greater in the presence of developmental defects of enamel (DDE). The aim was to determine whether the presence of DDE in the primary teeth of preschool children increases the risk of dental caries in the primary dentition after a period of approximately 2 years. This study was conducted in two stages: baseline (T0) and follow-up (T1). At T0, examinations were conducted for the diagnosis of enamel defects using the DDE index (FDI, 1992), dental caries, and oral hygiene. The participants were allocated to two groups according to the presence (affected) or absence (unaffected) of DDE. At the second evaluation (T1), examinations were performed for the diagnosis of dental caries. Poisson regression analysis with a multilevel approach was used to determine the association between DDE and dental caries. The two levels of the analysis were tooth and child. Among the 339 children (113 affected and 226 unaffected) examined at baseline (T0), 325 were re-examined at follow-up (T1). According to the multilevel analysis, teeth with enamel hypoplasia had a greater risk of having dental caries (RR: 1.99; 95% CI: 1.19-3.33). The risk of caries was greater on posterior teeth (RR: 2.59; 95% CI: 2.18-3.07) and maxillary teeth (RR: 1.48; 95% CI: 1.26-1.75) that had DDE at T0. On the child level, dental caries at T1 was associated with having dental caries at T0 (RR: 1.38; 95% CI: 1.32-1.46). In conclusion, enamel hypoplasia and previous dental caries are risk factors for carious lesions in the primary dentition.

[An experimental study of the effect of extraction and retention of canine primary intruded teeth to the permanent successors]

Objective: To compare the influence of extraction and retention of the intruded dogs' teeth on permanent successors. Methods: Nine healthy 45-days-old Chinese rural puppies were selected, and six were submitted to the intrusion of the bilateral canine. Intruded teeth on the left side were extracted 30 minutes later and the teeth on the right side were kept in their sockets. After 8 months, all dogs were sacrificed. General observation, periapical radiograph and cone beam CT were used to observe the preoperative and postoperative deciduous teeth, permanent germs and permanent teeth development. The structure and content of successors' enamel were observed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Results: In the extraction groups, the enamel hypoplasia was found in 19 permanent successors, ectopic eruption in 2 cases and abnormal teeth were in 19 cases in total (79%). In the retention groups, enamel hypoplasia of the permanent successors occurred in 2 cases, root dilaceration in 6 cases, and ectopic eruption in 5 cases, retained deciduous teeth in 3 cases, and there were 22 abnormal teeth in total (92%). In blank control group, there was no abnormal teeth. The major effect of intruded deciduous teeth on the permanent successors exhibited enamel hypoplasia [85% (41/48)], presented as enamel coloration and enamel defect (P=0.416). Conclusions: The intruded deciduous teeth should be removed early in order to reduce the effect on the permanent teeth.

[A 2-year cohort study on the caries risk assessment of 3-year-old caries-free children using Cariostat caries activity test]

Objective: To evaluate the caries status of a cohort of 3-year-old caries-free children from 2 kindergartens in Beijing in a period of 2 years by using Cariostat caries activity test and to assess the sensitivity and specificity of Cariostat score as a caries risk indicator for caries-free children. Methods: Totally 426 3-year-old caries-free children from 2 kindergartens in Beijing were recruited in the present study. Informed consents were obtained from the children's parents. Dental plaque samples of the children were collected and the Cariostat caries activity tests were conducted at baseline and once a year for 2 years. After two years, the caries status of the cohort children were re-evaluated and the caries incidences amongst children with high (2.0, 2.5, 3.0), medium (1.5) and low (1.0, 0.5, 0.0) levels of Cariostat scores were compared and analyzed. Results: Totally 864 3-year-old children from 2 kindergartens were screened before the study startedand 426 (49.3%) children were caries free. After 2-year follow-up, 312 out of 426 (73.2%) remained in the study. The overall caries incident rate was 46.5% (145/312). The caries incident rate of children with high level of Cariostat scores was 88.9% (88/99), while the caries incident rates of children with medium and low levels of Cariostat scores was 38.7% (36/93) and 17.5% (21/120), respectively. The sensitivity and specificity of the Cariostat test in assessing the caries risk of 3-year-old caries-free children in a period of 2 years were 60.7% and 93.4%, respectively. Conclusions: Cariostat caries activity test can be used as an indicator to predict the caries risk of 3-year-old caries-free children. Comprehensive caries management could be conducted for children in kindergartens based on the caries risk assessment results of caries experience and the Cariostat score.

Pulp bleeding color is an indicator of clinical and histohematologic status of primary teeth

OBJECTIVES

This study was carried out to investigate whether the changes in hematologic characteristic and color of pulpal bleeding is associated with clinical and histologic status of the pulp in primary teeth.

MATERIALS AND METHODS

A total of 211 primary molars in 103 patients, 3-6 years old, were treated. One hundred eight teeth had pulpectomy, 57 teeth had pulpotomy after pulp exposure during caries excavation, and 46 teeth had pulpotomy after accidental pulp exposure in sound dentin. After pulpal exposure, pulpal blood was collected in capillary tubes for blood color and hematologic assessment. Coronal and radicular pulp tissues were amputated for histologic assessment.

RESULTS

Blood color was significantly darker in pulpectomy cases and samples with severe inflammation. The differences were clinically perceptible by the human eye. A significant negative correlation was detected between white blood cell (WBC) count and blood color. The counts of neutrophils and lymphocytes were significantly different between treatment groups. In addition, WBC, eosinophil, monocyte, neutrophil, and basophils counts were significantly different between degrees of inflammation in coronal pulp. Moreover, severe inflammation was higher in pulpectomy group versus pulpotomy groups. Pulp tissue calcification was also significantly higher in the pulpectomy cases.

CONCLUSIONS

Considering the significant difference in pulpal blood color between the pulpectomy and pulpotomy cases, and between the different levels of pulpal inflammation; blood color can be a valid clinical diagnostic criterion of pulpal status and can be used for the selection of appropriate pulp treatment strategy.

CLINICAL RELEVANCE

This study shows that pulp bleeding color can be used for selection of an appropriate pulp treatment method in primary teeth.

Prevalence, Type and Etiology of Dental and Soft Tissue Injuries in Children in Croatia

The prevalence, type and etiology of dental and soft tissue injuries and relationship between the time of arrival and sustaining soft tissue injury were analyzed in this retrospective study conducted at the Department of Pediatric Dentistry, University Dental Clinic in Zagreb, Croatia, during the 2010-2014 period using documentation on 447 patients (264 male and 183 female) aged 1-16 years with injuries of primary and permanent teeth. The highest prevalence of traumatic dental injury (TDI) was found in the 7-12 age group and maxillary central incisors were most frequently affected (80.9%) in both primary and permanent dentitions. Enamel-dentin fracture without pulp exposure (31.9%) was the most common TDI of dental hard tissue in both dentitions, whereas subluxation (27.3%) was the most common periodontal tissue injury type. The most frequent location, cause and seasonal variation of trauma were at home, falling and spring. Soft tissue injuries were observed in 203 (45.4%) patients. Soft tissue injuries were less likely when fewer teeth were traumatized (p<0.001). Comparison of children with and without soft tissue injuries yielded a statistically significant difference in the time to arrival between primary and permanent teeth (p<0.01). Because soft tissue injuries include bleeding and clinical presentation appears more dramatic, the time elapsed between injury and initial treatment was shorter than in non-bleeding injuries, pointing to the need of education focused on parents and school teachers regarding the importance of immediate therapy for both bleeding and non-bleeding TDIs.