The effects of estrogen deficiency on glycosylation of odontoblasts in rats

Clinical determination of anatomical diameter in different dental groups correlating them with gender, age, tooth/canal and pulpoperiradicular diagnosis: an observational clinical study

The aim of this observational clinical study (OCS) was to determine the clinical anatomical diameter (CAD) in several dental groups, thus correlating them with gender, age, tooth/canal and pulpoperiradicular diagnosis. Three-hundred fifty-nine teeth/584 vital or necrotic root canals from patients of both genders and different ages composed the sample. After performing the necessary previous procedures, K-Flexofiles were used to determine the CAD. Then, the gender and age of the patients, as well as the pulpoperiradicular diagnosis of the teeth were tabulated to conduct the statistical analysis (p < 0.05). Of the 359 teeth/584 root canals evaluated, 208/342 were from women (mean age 38.85 ± 13.42 years) and 151/242 were from men (mean age 45.41 ± 14.90 years). Statistically significant differences between the CAD means of root canals from women and men were not identified (p = 0.411). The analysis of the correlation between the CAD and age also showed a total independence (p = 0.271). Teeth with pulp necrosis and asymptomatic apical periodontitis diagnosed radiographically (TPNAAPDR) had a significantly larger CAD mean than teeth with pulp necrosis and no asymptomatic apical periodontitis diagnosed radiographically (TPNNAAPDR) and teeth with vital pulp and normal apical tissues (TVPNAT) (p = 0.0297); and the last two did not differ statistically (p > 0.05). The largest CAD mean was observed in single canals of maxillary central incisors. The lowest values of this variable were identified in the mesiobuccal and mesial canals of maxillary and mandibular first molars, respectively. The CAD of the root canals was influenced only by the root canal/tooth and pulpoperiradicular diagnosis.

Analysis of obtaining apical patency indexes during endodontic treatments considering gender, age, pulpoperiradicular diagnosis and canal/tooth-A clinical study

This study aimed to perform an analysis of obtaining apical patency indexes during endodontic treatments considering gender, age, pulpoperiradicular diagnosis and canal/tooth (n. 639/383). Following previous clinical procedures, a thin K-File (No. 20, 15, 10 or 08) was used to achieve apical patency. These specific data and some demographic and clinical information were submitted to the statistical analysis (p < 0.05). Significant statistical differences were not identified considering gender (p = 0.156) and age (p = 0.793). However, in 14.6% of the canals of vital teeth and 14.1% of the canals of necrotic teeth without periapical lesions, apical patency could not be achieved, which occurred in only 7% of the canals of necrotic teeth with periradicular disease (p = 0.009). Considering canal/tooth, apical patency was more challenging to obtain in canals of posterior teeth (p = 0.000). The pulpoperiapical diagnosis and canal/tooth significantly influenced the obtaining of apical patency.

Digitilized Radiographic Analysis of Coronal Pulp for Age Estimation in Adults using Tooth Coronal Index Method – A Pilot Study

Background: Teeth have become a valuable index to estimate age of an individual in forensic odontology. Although various methods have been reported in forensic literature for age estimation, radiographic methods are simple and require less expertise. Digitalization of panoramic radiographs and intraoral periapical radiographs helps in obtaining the more precise images and accurate measurements. Secondary dentin continuously gets deposited on pulpal surface throughout the life thus reducing the size of the pulp cavity. The Tooth Coronal Index (TCI) method is the indirect assessment of secondary dentin deposition for age estimation. Aim: This study aims to estimate the Tooth Coronal Index of mandibular first molar and its correlation with chronological age to derive a regression equation. Materials and Methods: A total of 50 adults above 20 years of age were selected from the outpatient department of our college. Digital intraoral periapical radiographs were taken by using Radiovisiography (RVG) for mandibular first molar. The crown height and Coronal Pulp Cavity Height were measured and then TCI was calculated. Further the data were subjected to statistical analysis. Results: Statistically significant difference was observed between age and TCI (p<0.05*) and statistically insignificant difference observed between gender and TCI (p>0.05). Conclusion: The Tooth Coronal Index provides more accurate estimation of age and it is a simple, non invasive and cost-effective method that could be easily applied for both living and dead individuals without any highly specialized equipment.

Coronal pulp: An age biomarker - A cross-sectional radiographic study in children

Background:

Age plays an important role in personal identification, treatment planning, forensic dentistry, and legal issues. It is one of the key identification tools for distinguishing one person from another and one population from another. An intraoral radiographic technique for age estimation is an easier approach. The widely accepted age estimation method in children is the Demirjian system. Tooth coronal index is another method that gained popularity for adult age estimation.

Aim:

This study aims to estimate the tooth coronal index (TCI) of mandibular right and left second deciduous molar and its correlation with chronological age to derive a regression equation.

Settings and Design:

The present study is a cross-sectional radiographical study which is conducted in AME's Dental College and Hospital, Raichur, Karnataka, India.

Materials and Methods:

A total of 100 children aged 5–10 years were selected. Digital intraoral periapical radiographs were taken for right and left deciduous mandibular second molar. The length of the tooth crown and the coronal pulp cavity were measured. Statistical Analysis: Further, the data are subjected to student's unpaired t-test and ANOVA test for the statistical analysis and simple linear regression to derive the regression equation.

Results:

TCI showed a statistically significant reduction with increasing age in both right and left mandibular deciduous second molar (P ≤ 0.05), and the strength of the correlation is moderate (r = −0.59) if age is correlated with TCI using simple linear regression.

Conclusion:

The tooth coronal index method is found as a simple, noninvasive, nondestructive and cost-effective method for age assessment in children.

Oxytocin Facilitates Dentinogenesis of Rat Dental Pulp Cells

INTRODUCTION

Oxytocin (OT) is a neurohypophysial hormone that plays a role in lactation and parturition and exerts diverse biological actions via the OT receptor. Recently, several studies have reported that OT stimulates bone formation by osteoblasts in osteoporosis. We focused on OT and hypothesized that OT can stimulate the differentiation of odontoblasts as well as osteoblasts. The aim of this study was to verify whether OT is an essential factor in dentinogenesis; we examined the effects of OT on dentinogenesis using a long-term culture system of rat dental pulp cells.

METHODS

Using a culture system of rat dental pulp cells with Otr knocked out by CRISPR-Cas9 genome editing, we examined the effects of OT on odontoblastlike cell differentiation as reflected by dentin formation.

RESULTS

We confirmed that OT stimulated mineralized nodule formation and the expression of both dentin sialoprotein and bone Gla protein messenger RNAs (mRNAs) in the culture system. Interestingly, the cultured cells treated with OT also exhibited an increase of both Wnt10a and Lef-1 mRNA. The Otr knockout cells showed inhibition of nodule formation and mRNA expression, and these phenomena remained despite OT treatment. These results indicate the following: OT regulates odontoblastlike cell differentiation via the OT receptor, it stimulates dentin formation, and the Wnt canonical pathway is closely related to these effects.

CONCLUSIONS

The present results suggest that OT can promote odontoblastlike cell differentiation, resulting in increased dentin formation, and that OT could be an important factor for dentinogenesis.

Short-term and long-term effects of osteoporosis on incisor teeth and femoral bones evaluated by Raman spectroscopy and energy dispersive X-ray analysis in ovariectomized rats

There are few published data on the relationship between loss of bone mass due to osteoporosis and poor tooth quality. This study analyzed the effects of osteoporosis on incisor teeth and femoral bones using optical techniques in rats. Twenty female Wistar rats aged 6 months (n = 20) were randomized into two groups: control group, non-ovariectomized rats (n = 10); ovariectomy group, ovariectomized rats to induce osteoporosis (n = 10). Each group was subdivided randomly into two groups containing five rats each as follows. Control group 1: non-ovariectomized rats euthanized at the age of 9 or 3 months post-ovariectomy (n = 5); Control group 2: non-ovariectomized rats euthanized at the age of 1 year or 6 months post-ovariectomy (n = 5); ovariectomy group 1: ovariectomized rats euthanized at the age of 9 months or 3 months post-ovariectomy (n = 5); ovariectomy group 2: ovariectomized rats euthanized at the age of 1 year or 6 months post-ovariectomy (n = 5). The incisor teeth and femoral bones of Wistar rats were removed to perform Raman spectroscopy using an excitation laser at 785 nm. In addition, an energy-dispersive X-ray spectrometer system was used to evaluate calcium (Ca) and phosphorus (P). The main findings included significant changes (p < 0.05) for phosphate and carbonate band areas for both incisor teeth and femur bones. In addition, there was significant negative correlation between the P concentration and phosphate/carbonate ratio (lower P content-larger ratio, p < 0.05) for incisor teeth and femoral bones. The proline and CH₂ wag band areas were significantly reduced only for the incisor teeth (p < 0.05). Therefore, Raman spectroscopy assessed the compositional, physicochemical and structural changes in hard tissue. The current study also pointed out the possible action mechanisms of these changes, bone fracture risk and dental fragility. It is important to emphasize that poor dental quality may also occur due to osteoporosis.

Spatiotemporal expression of sclerostin in odontoblasts during embryonic mouse tooth morphogenesis

INTRODUCTION

Sclerostin is the product of the SOST gene. Loss-of-function mutations in the SOST gene result in a high bone mass phenotype, thus confirming that sclerostin is a negative regulator of bone mass. SOST knockdown in humans also causes oral and dental malformations. However, the relationship between sclerostin and tooth development is unclear.

METHODS

Using immunohistochemical techniques, we investigated sclerostin expression during fetal mouse tooth development and adult mouse tooth morphogenesis.

RESULTS

Sclerostin was expressed in the secretory odontoblasts located along the ameloblasts of fetal mouse tooth germ and adult incisor. Sclerostin expression was also observed in the fetal and adult osteocytes in the jaw bone.

CONCLUSION

These results suggest that sclerostin, one of the important regulatory factors of differentiated odontoblast function, may usable in vital pulp therapy.

Three-dimensional observation of decrease in pulp cavity volume using micro-CT: age-related change

We investigated three-dimensional decrease in the volume of the pulp chamber caused by age-related secondary dentin formation using micro-CT and evaluated the applicability of the results to evaluation of age taking into account sex, age and tooth type. Decrease was slightly higher in females than in males, and a higher correlation between decrease and aging was observed in females. A comparison between age-groups revealed that decrease progressed between the fifties and sixties in males, and the forties and fifties in females. A stronger correlation between aging and decrease was observed in the mandibular central incisors than in the mandibular second premolars. This correlation was higher than other correlations between sexes and age-groups.