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Objectives: To find radiographic association of the root pulp visibility and periodontal ligament visibility stages of lower second molar teeth with chronological age., Methods: The prospective, analytical, cross-sectional study was conducted after approval from the ethics review committee of Ziauddin University, Karachi, and comprised digital orthopantomograms from 2020 to 2022. The orthopantomograms related to lower second molar teeth from the left side of the mandible of individuals of either gender aged 18-40 years. The orthopantomograms were subjected to stage classification to assess the radiographic root pulp visibility and periodontal ligament visibility of the lower second molar teeth. Data was analysed using SPSS 25., Results: Of the 260 orthopantomograms, 140(53.8%) belonged to female subjects and 120(46.2%) to male. The overall median age of the subjects was 24 years (interquartile range: 7 years). There were 164(63.1%) subjects aged 18-25 years, 70(26.9%) aged 26-33 years, and 26(10%) aged 34-40 years. A positive correlation was noted between age and stages of radiographic root pulp visibility and periodontal ligament visibility (p<0.05). The individuals found at stages 0 and 1 for root pulp visibility were aged at least 18 years, and for stage 2, the corresponding value was 21 years. For periodontal ligament visibility, the minimum age for stage 0 was 18 years, while for stages 1 and 2, the corresponding values were 21 and 25 years., Conclusions: Lower age was found to be associated more with stage 0 of root pulp visibility and periodontal ligament visibility.

Background: The study evaluates the feasibility of employing the radiographic visibility of the root pulp and periodontal ligament in mandibular molars for age estimation, particularly focusing on the 18 years of age threshold. This study additionally investigates the potential of root canal width reduction in mandibular molars, as a reliable method for forensic age estimation in living individuals., Materials and Methods: A cross-sectional study was conducted to assess the radiographic visibility of the root pulp (RPV) and the root canal width (RCW) of mandibular first, second, and third molars along with the radiographic visibility of the periodontal ligament (PLV) of mandibular third molars, in a sample of 403 individuals aged 16-25 years (220 males and 183 females). Data regarding age for different stages of RPV and PLV and various types of RCW were recorded and observed for sex-based differences. Results obtained were tabulated and descriptive statistics were applied to summarise the findings., Results: Individuals over 18 years old were classified with higher accuracy using stage 3 of the RPV scoring system in all mandibular molars (first, second, and third) compared to stage 2, which was also effective for the second and third molars. This result held regardless of sex and side examined. Additionally, root canal width (RCW) assessment demonstrated that individuals with RCW types A, B, and C were more likely to be under 18 years old in both sexes. Conversely, individuals with RCW type U on the right side for males and the left side for females exhibited a higher likelihood of being above 18 years old., Conclusion: The study suggests that the assessment of mandibular molars could potentially serve as an auxiliary tool in age estimation methods, particularly for approximating individuals around the 18 years of age threshold. Further investigation is warranted to explore the potential application of root canal width measurements in forensic age estimation., Competing Interests: The authors report no conflicts of interest in this work., (Copyright© 2024 IOFOS This work is published and licensed by International Organization for Forensic Odonto-Stomatology.)

Aim: The objective of the present study was to investigate the association between the anatomical characteristics of different tooth groups and the diffusion and bleaching effect of hydrogen peroxide (H2O2)., Materials and Methods: Computed tomography (CT) images from five patients were used to assess the hard tissue thickness and pulp volume (PV) of four tooth groups: lower (mandibular) incisors (LI), upper (maxillary) incisors (UI), canines (C), and premolars (PM). Additionally, 80 bovine tooth disks were divided into four groups (n &#61; 20) to match the thickness of each tooth group studied. All the specimens were exposed to a 35% H2O2 bleaching gel, with 50 µL applied for 45 min during the first, second, and third sessions. Diffusion was evaluated using the peroxidase enzyme method. Color change analyses (∆E, ∆E00, and ∆WID) were performed after the three application sessions and 7 days after the bleaching treatment using a spectrophotometer., Results: The PM group showed greater thickness and PV, followed by the C, UI, and LI groups (P 0.001). The LI group had six times greater H2O2 diffusion compared with the PM group (P 0.001), while the PM group exhibited a PV nine times larger than the LI group. Furthermore, the LI and UI groups achieved color saturation with one fewer session than the C and PM groups., Conclusions: Specific tooth groups have anatomical characteristics that interfere with bleaching treatment in terms of the diffusion and whitening effect of H2O2. Furthermore, the diffusion capacity of H2O2 was inversely proportional to the thickness of the tooth groups.

Background: Forensic odontology is a subfield of forensics that can assist in determining age, gender, and other demographic factors., Objective: The focus of this research is to ascertain age by tooth volume ratio of permanent maxillary canines using a CBCT scan., Methods: In this retrospective investigation, 1000 CBCT images were gathered and focused on only fully developed maxillary canines. For each of the maxillary canines, the researchers measured and calculated the volume of the pulp chamber, root canal, and entire tooth using the ITK Snap programme. The pulp volume to tooth volume ratio was computed. The equation AGE = 59.208 - (583.652 x pulp volume/tooth volume) was then used to compute age. The samples were divided into 5 age groups; 13-20, 21-30, 31-40, 41-50, and 51-60. The age was calculated for samples in each group and it was compared to the actual age., Results: Between individuals' actual age and computed age, the study discovered a statistically significant positive association. While groups 3, 4, and 5 demonstrated positive but weaker correlations (r= 0.854, r= 0.658, and r= 0.612, respectively), groups 1 and 2 displayed statistically significant strong positive correlations (r= 0.987 and r= 0.923, respectively). The average total discrepancy between the age that was computed and the actual age was 2.45 1.344., Conclusion: The study found a statistically significant positive correlation between computed age and actual age, with the younger age groups 1 (13-20) and 2 (21-30) showing the strongest relationships. This underlines its potential success in court, particularly when dealing with young criminals.

Objectives: One role of dental pulp is in the upkeep and maintenance of dentine. Under wear, odontoblasts in the pulp deposit tertiary dentine to ensure the sensitive internal dental tissues are not exposed and vulnerable to infection. It follows that there may be an adaptive advantage for increasing molar pulp volume in anthropoid primate taxa that are prone to high levels of wear. The relative volume of dental pulp is therefore predicted to covary with dietary abrasiveness (in the sense of including foods that cause high degrees of wear)., Materials and Methods: We examined relatively unworn lower second molars in pairs of species of extant hominoids, cebids, and pitheciids that vary in the abrasiveness of their diet (n = 36). Using micro-CT scans, we measured the percent of tooth that is pulp (PTP) as the ratio of pulp volume to that of the total volume of the tooth., Results: We found that in each pair of species, the taxa that consume a more abrasive diet had a significantly higher PTP than the closely related taxa that consume a softer diet., Conclusions: Our results point to an adaptive mechanism in the molars of taxa that consume abrasive diets and are thus subject to higher levels of wear. Our results provide additional understanding of the relationship between dental pulp and diet and may offer insight into the diet of extinct taxa such as Paranthropus boisei or into the adaptive context of the taurodont molars of Neanderthals., (© 2021 Wiley Periodicals LLC.)

Objective: The teeth have been used as a supplementary tool for sex differentiation as they are resistant to post-mortem degradation. The present study aimed to develop a new novel informatics framework for predicting sex from linear tooth dimension measurements achieved from cone beam computed tomography (CBCT) images., Method and Materials: A clinical workflow using different machine learning methods was employed to predict the sex in the present study. The CBCT images of 485 subjects (245 men and 240 women) were evaluated for sex differentiation. Nine parameters were measured in both buccolingual and mesiodistal aspects of the teeth. We applied our dataset to Naïve Bayesian (NB), Random Forest (RF), and Support Vector Machine (SVM) as classifiers for prediction. Genetic feature selection was used to discover real features associated with sex classification., Results: The 10-fold cross-validation results indicated that NB had higher accuracy than SVM and RF for sex classification. The genetic algorithm (GA) indicated that the model could fit the data without using the enamel thickness and pulp height. The average classification accuracy of our clinical workflow was 92.31 %., Conclusion: The results showed that NB was the best method for sex classification. The application of the first molar teeth in sex prediction indicated an acceptable level of sexual classification. Therefore, these odontometric parameters can be applied as an additional tool for sex determination in forensic anthropology., Competing Interests: Declaration of Competing Interest The authors reported no declarations of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objectives: Age estimation is one of the most important factors in forensic medicine. Measuring secondary dentin deposition using cone-beam computed tomography images is an easy and noninvasive method. The aim of this study was to evaluate cone-beam computed tomography images as a reliable method to estimate chronological age by pulp/teeth ratio in anterior teeth in Iranian population., Methodology: A total of 649 CBCT images from 377 Iranian patients aged between 20 and 69 years were evaluated. Pulp/teeth ratio (PTR) in maxillary and mandibular canine and central incisor teeth was measured in the axial and sagittal sections using OnDemand 3D Dental software. The Pearson correlation coefficient was determined to evaluate the correlation between the variables. Linear regression analysis, as well as age estimation formula, was used for each tooth separately., Results: The regression analyses indicated that maxillary central incisors were more reliable for age estimation (R2=0.586 and standard error of estimate=7.045) compared with the other anterior teeth studied. Maxillary canine teeth had the lowest predictive power (R2=0.392 and standard error of estimate=8.387). Also, comparison of the axial and sagittal sections showed that the axial sections had a higher predictive power. (R2=0.48 for axial plans and R2=0.328 for sagittal plans)., Conclusion: The use of cone-beam computed tomography in age estimation by pulp/teeth ratio of anterior teeth is useful and a reliable method for age estimation in Iranian population.

The Kvaal method as a non-invasive method for age estimation based on the changes of pulpal size caused by secondary dentin deposition has been applied to different ethnics. However, its results are often conflicting and its accuracy is relatively poor. This study aimed to verify the applicability of the Kvaal method to estimate the ages of the Chinese population using digital panoramic radiographs and to formulate specific regression equations for use in Chinese subjects. A sample of 360 digital panoramic radiographs from northern Chinese population were selected, from which the pulpal size and width of six tooth types (maxillary central incisor, lateral incisor, second premolar, mandibular lateral incisor, canine, and first premolar) were measured using Kvaal's method. Then, inter- and intra-observer reliabilities were calculated to evaluate the reproducibility of those measurements. The correlation between chronological age and measurements was also examined and the Chinese-specific equations for age estimation were conducted. After comparing the accuracy of the Chinese-specific equation with the original Kvaal equation, the age of the Chinese population was clearly overestimated by Kvaal's equation, and a Chinese-specific equation could ameliorate age prediction accuracy. In addition, the residuals of the Chinese-specific equation were significantly lower than that of the original Kvaal's method. Thus, we concluded that the original Kvaal equation cannot accurately estimate age in the Chinese population. Although accuracy improved using the Chinese-specific equation that was based on Kvaal's methodology, the standard deviation remained large. In view of the lack of accurate age estimation methods for adults, we propose finding more correlated variables or combining other age estimation methods to increase the accuracy for adult age estimation., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Forensic odontology plays an important role in human identification and dental age estimation is an integral part of this process. The aim of the study was to investigate the association between chronological age and pulp/tooth volume ratio in a Malaysian population (Malays and Chinese) from cone-beam computed tomography (CBCT) scans, enhanced with Mimics software. Three hundred CBCT scans of 153 males and 147 females, aged between 16 and 65 years were divided into 5 age groups. Volumetric analysis of the pulp/tooth ratio was performed in maxillary left canines, maxillary right canines and maxillary right central incisors. Simple linear regression and Pearson correlation analysis indicated the strongest coefficient of correlation (R) values for maxillary right central incisors (0.83) followed by maxillary right canines (0.74) and maxillary left canines (0.73). Fisher's Z test indicated that dental age estimation is gender independent. The derived regression equations were further validated on an independent group of 126 teeth. The results indicated mean absolute error (MAE) values of 6.48 and 8.58 years for maxillary right central incisors and maxillary canines respectively. It was also noticed that MAE values were higher among the age groups ranging from 46 to 65 years. This study showed that a volumetric change in the pulp cavity with age is a valuable assessment method for dental age estimation among Malaysian population., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Introduction: Current pulp revascularization procedures in teeth with necrotic pulps and open apices have produced histologic evidence of connective tissue growth, cementum, and bone within the root canals of experimental animals. This study aims to investigate the effect of maintaining uninflamed residual apical pulp tissue on the histologic outcome of pulp-dentin complex regeneration after a revascularization procedure in immature ferret cuspid teeth., Methods: Twenty-eight cuspid teeth from 7 young male ferrets were used in this experiment. Seven teeth were reserved to serve as positive control samples without any treatment. In another 7 teeth, the pulp was completely extirpated (negative control), whereas the pulp of the remaining 14 teeth were removed to either 1-2 mm short of the apex (7 samples) or 2-4 mm short of the apex (7 samples). Blood clots were covered with mineral trioxide aggregate at the cementoenamel junction level of each tooth. Three months later, block sections were removed for histologic evaluations, and the data were statistically analyzed with the chi-square test (P < .05)., Results: All teeth with complete pulp extirpation showed the presence of bone inside the root canal. In contrast, the root canals for most teeth with pulp amputation 1-4 mm from the radiographic apex were filled with normal pulp, which extended coronally to the mineral trioxide aggregate, where hard tissue bridges had formed., Conclusions: Based on these results, we concluded that regeneration of the pulp-dentin complex is possible when the apical 1-4 mm of the apical pulp remains intact in immature teeth., (Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Background: Equine incisors are often reduced in height during corrective dental procedures. Increased knowledge of subocclusal dentine thickness and pulp morphology may help prevent iatrogenic pulpar exposure. Although such data exist for equine cheek teeth, there are currently no reliable data for incisors., Objectives: To measure the distances between pulp cavities and the occlusal as well as the labial surfaces of equine incisors and to test if these distances change with age. Furthermore, pulp morphology with regard to number and orientation of pulp horns was investigated., Study Design: Observational study using cadaver material and high-resolution computed tomography., Methods: Upper and lower incisor arcades were removed from heads of 13 horses and scanned with high-resolution computed tomography. 3D Models were reconstructed and configuration as well as number of the pulp horns was evaluated. Anatomical marker points were set to measure distances between the pulp horn tips and the labial and occlusal surfaces., Results: Subocclusal dentine thickness ranged between 1.5 and 11.7 mm in upper and 0.7 and 6.7 mm in lower incisors. It decreased with tooth age. Distance to labial aspect ranged between 3.5 and 9.0 mm in upper and 3.8 and 8.1 mm in lower incisors and increased with tooth age., Main Limitations: Details of horse management, feeding and previous dental care were not available. Therefore, it remains unknown how these factors influenced the results., Conclusions: Although mean subocclusal dentine thickness of greater than 4.1 mm was found, equine incisors occasionally have less than 1 mm of thickness with potential for iatrogenic pulpar exposure during incisor reduction. Therefore, great care should be exercised by any practitioner during incisor reduction., (© 2018 EVJ Ltd.)

Endodontium, otherwise referred to as pulp-dentin complex or endodont. This term includes two tooth tissues: dentin and pulp, which constitute a structural and functional unity. These tissues have a huge, inseparable influence on each other - the pulp (inter alia) nourishes the dentine, while the dentin forms a protective barrier for the pulp. They develop from the papillary tissue (Latin: papilladentis) from mesenchymal tissue. Nevertheless, in clinical practice this structural-functional complex is often treated as two separate tissues, and not as a whole. Adequate knowledge of the structure, function and protective mechanisms of the endodontium produces successful results in the treatment. The appropriate choice and application of the therapeutic methods and materials to the dentin secures vitality of both tissues of this complex.

Introduction: No in vivo study has been reported on the mechanical reinforcement of a tooth after regenerative endodontic treatment (RET). The present work aimed to evaluate the concurrent use of platelet-rich fibrin (PRF) with a blood clot (BC) in RET concerning periapical healing, root development, and tooth structural reinforcement., Methods: In our study, 24 premolars from 3 beagle dogs were assigned into control, BC, and PRF + BC groups. Periapical healing was monitored with quantitative measurements of root elongation and thickening radiographically. Tooth biomechanical integrity was assessed with the fracture resistance test. Histologic evaluation was conducted., Results: There was a significant difference among the periapical radiolucency decreasing rate of the control (43.75%) and the BC (100%) and PRF + BC (100%) groups (P < .05). The increase of root length and thickness in both the BC and PRF + BC groups was significantly greater than that in the control group (P < .05). No significant difference was detected between the 2 experimental groups regarding periapical healing or root development (P > .05). Teeth in the BC (249.3 ± 64.1 N) and PRF + BC (281.7 ± 37.8 N) groups had significantly higher fracture resistance than those in the control group (108.5 ± 23.3 N) (P < .05). No significant difference was revealed between the BC and PRF + BC groups (P > .05). Histologic evidence of cementumlike tissue deposition along the canal wall with scattered bonelike tissue in the canal was observed., Conclusions: Either a combination of PRF with BC or BC alone could improve periapical healing, induce root development, and reinforce tooth structure. No additional benefit of PRF to BC in RET was found., (Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Aim: Platelet-rich plasma (PRP), which is a concentration of growth factors found in platelets, may be a suitable material for pulp regeneration. The aim of this animal study was a histological evaluation of PRP on pulp regeneration in nonvital teeth with immature apices., Materials and Methods: A total of 40 premolar dogs' teeth were chosen for this study. After general anesthesia, the teeth were exposed, and subsequently, pulps were removed and the cavities were opened to the oral cavity. After 2 weeks, root canals were irrigated and disinfected with sodium hypochlorite with noninstrumentation technique, and triple antibiotic paste was placed inside the canals. Cavities were sealed with a temporary restoration. About 4 weeks later, canals were irrigated again and the teeth were randomly divided into three groups. Bleeding was evoked with overinstrumentation, then experimental materials for each group [PRP, mineral trioxide aggregate (MTA), and parafilm respectively] were placed over the bleeding, and orifices were sealed with MTA and glass ionomer. After 3 months, dogs were sacrificed and the teeth were separated from the jaws and sections prepared for histological evaluation., Results: Regeneration was shown in 44.7% of the samples. About 47.3% of the samples in the MTA group and 42.1% of the samples in the PRP group showed regeneration; however, no regeneration was observed in the parafilm group. Chi-square test showed no significant difference between groups I and II. The soft regenerative tissue included pulp-like tissue and vessels. Mineralized regenerative tissue included cementum-like, periodontal ligament-like, and bone-like tissues. No normal pulp and nerve tissue were observed., Conclusion: Both PRP and MTA may be ideal scaffolds to accelerate the regeneration process., Clinical Significance: Pulp repair in immature permanent teeth with weak roots has a better outcome than replacement of the pulp with gutta-percha or biomaterials.

Introduction: Information on the nerve fibers innervating the dental pulp is crucial for understanding dental pain and hypersensitivity. This study investigated the morphologic differences of parvalbumin (PV)-positive (+) myelinated fibers in 3 different regions of the human dental pulp., Methods: Light and electron microscopic immunohistochemistry for parvalbumin, a marker for myelinated fibers, and quantitative analysis were performed in the apical root, core of coronal pulp, and peripheral pulp of human premolar teeth., Results: About 40% of the myelinated fibers in the apical root pulp became unmyelinated in the core of the coronal pulp, and virtually all the remaining fibers became unmyelinated at the peripheral pulp. The size of myelinated axons decreased from root to peripheral pulp. PV+ axons showed extensive axonal varicosities in the peripheral pulp., Conclusions: These findings suggest that the myelinated fibers innervating the human dental pulp undergo extensive morphologic change in the extrapulpal region and in the coronal and peripheral pulp, and that PV-mediated regulation of calcium concentration and its downstream events may occur primarily in axonal varicosities in the peripheral pulp., (Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Throughout lifetime, the teeth are continuously exposed to numerous chemical and physical impacts, which cause the wear of the dental hard tissues, gingival recession and other oral changes with sometimes subsequent problems. Age-related wear of tooth surfaces reduces the dental enamel thickness and exposes deeper layers of enamel, which have different physical and chemical properties than the surface enamel. Gingival recession is the main causal factor of root caries and dentine hypersensitivity. Age-related changes in dentine include the formation of secondary dentine and the reduction in tubular lumen diameter (dentine sclerosis), which lead to a reduction in the volume of the pulp chamber. In addition to the reduction in the volume of pulp chamber, changes to the dental pulp also include dental pulp calcifications. The age-related physiological changes to the teeth should be carefully distinguished from pathological changes, especially when they induce pain or a negative impact on the oral health-related quality of life (OHRQoL) of the older individuals. Therefore, regular oral examinations coupled with early preventive measures should aim at maintaining oral health until old age., (© 2016 John Wiley & Sons Ltd.)

Introduction: Treatment of immature permanent teeth with necrotic pulp and apical pathosis constitutes a challenge for endodontists. The present study was done to evaluate the effect of age and apical diameter on the regenerative potential of young permanent immature teeth with necrotic pulps., Methods: Immature necrotic permanent maxillary incisors (n = 40) of patients 9-18 years old were divided into 2 groups according to the treatment protocol: group Y (younger age group), 9-13 years and group O (older age group), 14-18 years. Each group was further subdivided into 2 subgroups according to apical diameter, subgroup (n) (narrower diameter) between 0.5 and 1 mm and subgroup (w) (wider diameter) equal to or greater than 1 mm. Revascularization procedures were performed for all patients. Follow-up was done for up to 12 months. Standardized radiographs were digitally evaluated for increase in root length and thickness and decrease in apical diameter., Results: After the follow-up period, most of the cases demonstrated radiographic evidence of periapical healing. Group Y showed significant progressive increase in root length and width and decrease in apical diameter. Subgroup (w) representing wider apical diameter showed significant progress as well., Conclusions: It was found that revascularization procedures can be implemented in any age ranging from 9 to 18 years; however, younger age groups were better candidates for revascularization procedure than older ones. Regarding the apical diameter, regeneration procedures were successful with apical diameters as small as 0.5 mm. However, teeth with preoperative wider diameters (≥1 mm) demonstrated greater increase in root thickness, length, and apical narrowing., (Copyright © 2016 American Association of Endodontists. All rights reserved.)

Aim: The present study aimed to investigate the association between the tooth coronal index (TCI) and the pubertal growth stages (PGS) for children and adolescents., Materials and Methods: A cross-sectional study was performed using retrospectively collected panoramic and hand-wrist radiographs of 262 individuals (125 males, 137 females). The coronal height (CH) and the coronal pulp cavity height (CPCH) of the left mandibular teeth were measured. Then the TCI for which was calculated according to Ikeda et al (1985). The estimated TCI for individuals with the following PGS after Fishman (1987) are: SMI 4 (S), SMI 5 (DP3 cap), SMI 6 (MP3 cap) and SMI 7 (Mp5 cap). The associations between the TCI and the PGS were investigated by correlation coefficient of Spearman's rho, and the validity values for the PGS were computed., Results: Significant correlations were noted between the simple TCI values for premolars and molars and the PGS, and the highest correlation was for the summed TCI for both first and second molars. Utilizing the validity values of the summed TCI for both first and second mandibular molars, the PGS can be predicted as follows: S stage when TCI is 49.17 or lesser, DP3cap stage when TCI is 43.52 or lesser, MP3cap stage when TCI is 36.73 or lesser, and Mp5cap stage when TCI is 26.84 or lesser., Conclusion: The TCI values declined along with the maturational process in children and adolescents. The TCI for both first and second molars was the best predictor of the PGS., Clinical Significance: Panoramic photographs can be beneficial for prediction of the skeletal maturity and treatment planning without resorting to hand-wrist radiographs.

Cariopathogen Streptococcus mutans exists in infected dental pulp of deciduous teeth and is frequently linked with heart diseases. Organotypic (3D) dental pulp stem cell (DPSC) cultures/microtissues, developed to mimic the physiological conditions in vivo, were utilized to assess the bacterial impact on their (i) 3D structural configuration and (ii) recovery mechanisms. The cultures, developed in extracellular matrix (ECM) bio-scaffold (Matrigel™), interacted with WT and GFP-tagged bacterial biofilms by permitting their infiltration through the ECM. Challenged cell constructs were visualized by F-actin/nuclei staining. Their pluripotency (Sox2) and differentiation (osteocalcin) markers were assessed by immunocytochemistry. Secreted mineral was detected by alizarin red, and 3D structural arrangements were analysed by epi-fluorescence and confocal scanning microscopy. Bacterial biofilm/ECM-embedded DPSC interactions appeared in distinct areas of the microtissues. Bacterial attachment to the cell surface occurred without evidence of invasion. Surface architecture of the challenged versus unchallenged microtissues was apparently unaltered. However, significant increases in thickness (138.42 vs 106.51 µm) and bacterial penetration were detected in challenged structures causing canal-like microstructures with various diameters (12.94 -42.88 µm) and average diameter of 20.66 to 33.42 µm per microtissue. Challenged constructs expressed pluripotency and differentiation markers and secreted the mineral. Presented model shows strong potential for assessing pulp-pathogen interactions in vivo. S. mutans infiltrated and penetrated the microtissues but did not invade the cells or compromise major cell repair mechanisms. These findings would suggest reexamining the role of S. mutans as an endodontic pathogen and investigating DPSC resistance to its pathogenicity.

Recent theoretical progress potentially refutes past claims that paleodemographic estimations are flawed by statistical problems, including age mimicry and sample bias due to differential preservation. The life expectancy at age 15 of the Jomon period prehistoric populace in Japan was initially estimated to have been ∼16 years while a more recent analysis suggested 31.5 years. In this study, we provide alternative results based on a new methodology. The material comprises 234 mandibular canines from Jomon period skeletal remains and a reference sample of 363 mandibular canines of recent-modern Japanese. Dental pulp reduction is used as the age-indicator, which because of tooth durability is presumed to minimize the effect of differential preservation. Maximum likelihood estimation, which theoretically avoids age mimicry, was applied. Our methods also adjusted for the known pulp volume reduction rate among recent-modern Japanese to provide a better fit for observations in the Jomon period sample. Without adjustment for the known rate in pulp volume reduction, estimates of Jomon life expectancy at age 15 were dubiously long. However, when the rate was adjusted, the estimate results in a value that falls within the range of modern hunter-gatherers, with significantly better fit to the observations. The rate-adjusted result of 32.2 years more likely represents the true life expectancy of the Jomon people at age 15, than the result without adjustment. Considering ∼7% rate of antemortem loss of the mandibular canine observed in our Jomon period sample, actual life expectancy at age 15 may have been as high as ∼35.3 years., (© 2016 Wiley Periodicals, Inc.)

Objectives:: To determine the prevalence of three-rooted mandibular molars in a Brazilian population using cone beam computed tomography (CBCT) and to analyze the anatomy of mandibular first molars with three roots through micro-CT., Material and Methods:: CBCT images of 116 patients were reviewed to determine the prevalence of three-rooted first mandibular molars in a Brazilian subpopulation. Furthermore, with the use of micro-CT, 55 extracted three-rooted mandibular first molars were scanned and reconstructed to assess root length, distance between canal orifices, apical diameter, Vertucci's classification, presence of apical delta, number of foramina and furcations, lateral and accessory canals. The distance between the orifice on the pulp chamber floor and the beginning of the curvature and the angle of canal curvature were analyzed in the distolingual root. Data were compared using the Kruskal-Wallis test (α=0.05)., Results:: The prevalence of three-rooted mandibular first molars was of 2.58%. Mesial roots showed complex distribution of the root canal system in comparison to the distal roots. The median of major diameters of mesiobuccal, mesiolingual and single mesial canals were: 0.34, 0.41 and 0.60 mm, respectively. The higher values of major diameters were found in the distobuccal canals (0.56 mm) and the lower diameters in the distolingual canals (0.29 mm). The lowest orifice distance was found between the mesial canals (MB-ML) and the highest distance between the distal root canals (DB-DL). Almost all distal roots had one root canal and one apical foramen with few accessory canals., Conclusions:: Distolingual root generally has short length, severe curvature and a single root canal with low apical diameter.

Aim: The aims of this study are to identify which type of tooth has the strong relationship between age and pulp cavity/chamber volume among 13 types of tooth from the same dentition and to determine whether the inclusion of multiple types of tooth may improve the accuracy of age estimation., Materials and Methods: Cone beam computed tomography (CBCT) images from 115 females and 125 males aged between 16 and 63 years were analyzed. The DICOM data of all the images were imported into ITK-SNAP 2.4 for the calculation of pulp cavity/chamber volumes. Logarithmic regression analysis and multiple linear regression analysis were applied to establish the relationship between age and pulp cavity/chamber volumes., Results: Among the 13 types of tooth, maxillary second molars have the largest R (2) (0.491, 0.642, and 0.498) and the smallest SEE (8.119, 6.754, and 8.022) in male, female, and pooled gender samples, respectively. The multiple linear regression analysis for the combination of multi-types of tooth indicated that a larger R (2) (0.627, 0.701, and 0.631) and smaller SEE (7.100, 6.258, and 6.970) than the counterpart calculated from the logarithmic regression analysis of a single type of tooth in male, female, and pooled gender samples, respectively., Conclusion: The pulp chamber volume of the maxillary second molars has the largest correlation coefficient with age. Using multiple types of tooth may improve the accuracy of age estimation compared with only one type of tooth used.

Introduction: The morphologic features of accessory canals (ACs) were investigated by using micro-computed tomography technique with a centerline fitting algorithm., Methods: Ninety-three 3-mm-long apical root segments with unobstructed ACs were scanned by micro-computed tomography at 2.5-μm scanning resolution. After automatic segmentation, a centerline of the reconstructed lateral canal was developed, and the diameter, length, shape, and undulation of ACs were analyzed along the centerline., Results: Of 178 unobstructed ACs identified, the median diameter was 67.0 μm, the average length was 786.6 μm, the predominant shape was oval, and the undulation was tortuous rather than straight., Conclusions: The diameter, length, shape, and undulation may vary among ACs in particular from the pulpal space to the external root surface, which may complicate the debridement of the ACs., (Copyright © 2016 American Association of Endodontists. All rights reserved.)

Introduction: This study determined the gene expression profiles of the human coronal pulp (CP) and apical pulp complex (APC) with the aim of explaining differences in their functions., Methods: Total RNA was isolated from the CP and APC, and gene expression was analyzed using complementary DNA microarray technology. Gene ontology analysis was used to classify the biological function. Quantitative reverse-transcription polymerase chain reaction and immunohistochemical staining were performed to verify microarray data., Results: In the microarray analyses, expression increases of at least 2-fold were present in 125 genes in the APC and 139 genes in the CP out of a total of 33,297 genes. Gene ontology class processes found more genes related to immune responses, cell growth and maintenance, and cell adhesion in the APC, whereas transport and neurogenesis genes predominated in the CP. Quantitative reverse-transcription polymerase chain reaction and immunohistochemical staining confirmed the microarray results, with DMP1, CALB1, and GABRB1 strongly expressed in the CP, whereas SMOC2, SHH, BARX1, CX3CR1, SPP1, COL XII, and LAMC2 were strongly expressed in the APC., Conclusions: The expression levels of genes related to dentin mineralization, neurogenesis, and neurotransmission are higher in the CP in human immature teeth, whereas those of immune-related and tooth development-related genes are higher in the APC., (Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

This study aims to describe and analyze morphological and physical properties of deciduous teeth of Sus domesticus. Ultrastructural analysis, mineral composition and microhardness of enamel and dentine tissues were performed on 10 skulls of S. domesticus. External anatomic characteristics and the internal anatomy of the teeth were also described. Data regarding microhardness and ultrastructural analysis were subjected to statistical tests. For ultrastructural analysis, we used the analysis of variance (ANOVA) with Tukey's post hoc (p≤0.05) test. In the analysis of microhardness, the difference between the enamel and dentine tissues was analyzed by a Student's t test. Values were expressed as mean with standard error. The results of ultrastructural analysis showed the presence of an enamel prism pattern. A dentinal tubule pattern was also observed, with a larger diameter in the pulp chamber and the cervical third, in comparison to middle and apical thirds. We observed an average microhardness of 259.2kgf/mm(2) for enamel and 55.17kgf/mm(2) for dentine. In porcine enamel and dentine, the chemical elements Ca and P showed the highest concentration. The analysis of internal anatomy revealed the presence of a simple root canal system and the occurrence of main canals in the roots. The observed features are compatible with the functional demand of these animals, following a pattern very similar to that seen in other groups of mammals, which can encourage the development of research using dental elements from the pig as a substitute for human teeth in laboratory research., (Copyright © 2015 Elsevier GmbH. All rights reserved.)

Dentine becomes infected as a result of caries lesion formation on root surfaces and when lesions progress following cavitation of enamel lesions. However, this infection is unimportant because the driving force for lesion formation and progression is the overlying biofilm. This explains why root surface caries can be controlled by mechanical plaque control and fluoride, and restorations are not needed to arrest these lesions. Similarly, the infected dentine in cavitated coronal lesions does not have to be removed to arrest the lesion. If the lesion is either accessible or opened for cleaning by the patient or parent, the lesion can be arrested. Sealing of infected dentine within the tooth, either by a Hall crown in the primary dentition or by partial caries removal prior to placing a well-sealed filling, will also arrest the lesion. When restoring deep lesions in symptomless, vital teeth, vigorous excavation of infected dentine is likely to expose the pulp and make root canal treatment necessary. Thus complete excavation'is not needed and should be avoided. CPD/CLINICAL RELEVANCE: Root surface caries can be arrested by cleaning and fluoride application. Restorations are not essential. Vigorous excavation of softened dentine in deep cavities of symptomless, vital teeth is contra-indicated. It is not needed and increases the risk of pulp exposure.

Purpose: To evaluate the in vitro diffusion of 2-hydroxyethyl methacrylate (HEMA) from the resin cements through different thicknesses of dentin using high-performance liquid chromatography (HPLC) at two time intervals., Methods: 60 freshly extracted caries- and restoration-free human third molar teeth were used in this study. Standardized box-shaped Class I inlay cavities (6 mm long, 3 mm wide and 2 mm deep) were prepared in all teeth with a high-speed handpiece mounted on a standard cavity machine. The remaining dentin thickness (RDT) between the pulpal wall of the cavity and the roof of the pulp chamber was measured at multiple points for each tooth so that two main groups of 30 teeth each were prepared with an RDT range 0.5-1.9 and 2.0-3.5 mm, respectively. Each of these main groups was divided into three subgroups (n = 10), according to the resin cements tested (RelyX ARC, Panavia F 2.0, Multilink Automix). Lithium disilicate-based ceramic inlays (IPS Empress 2) were manufactured to restore the prepared cavities. A polypropylene chamber containing 1 ml distilled water was attached to the cemento-enamel junction of each tooth. Then, ceramic inlays were cemented with resin cements according to the manufacturers' instructions. Water elutes were analyzed by HPLC at 4.32 minutes and 24 hours. HEMA diffusion amounts were analyzed using three-way ANOVA and Tukey's HSD tests (P < 0.05)., Results: HEMA was detected in the pulp chamber elutes of all the teeth. The amounts of released HEMA did not significantly differ between time periods. The diffused HEMA amounts were significantly different between the RDT of 0.5-1.9 and 2.0-3.5 mm (P < 0.05) and between resin cements tested (P < 0.05). Decreasing RDT substantially increased the amount of HEMA that diffused through the dentin to the pulp space.

Age estimation involves the reconstruction of age by biological parameters such as skeletal and dental development in minors, or reduction of pulp chamber in adults, to gain indications concerning the chronological age of the person. In most cases, it is needed in forensic scenarios to verify if the supposed age of an individual is correct; in exceptional cases, age estimation is instead required by judicial authorities to create a new identity usually in persons who do not remember who they are.This article aims at reporting the case of J. who was found in 2005 with signs of amnesia because he did not remember his name and age. After several unsuccessful attempts at identifying him, the judicial authority decided to assign a new identity, which was to be constructed according to the real biological data of the individual. The help of a forensic pathologist and a forensic odontologist was then requested, and age estimation was reached by applying methods for adults based on the physiological reduction of pulp chamber. Dental age estimation yielded a final result of approximately 31 years, which was the new age assigned to the person.This article shows a peculiar application of dental age estimation, which can be used not only to ascertain or deny supposed age, but is sometimes needed to create a new identity.

Introduction: Clinicians routinely face conditions in which they have to decide whether the dental pulp can be saved or not. This study evaluated how reliable the clinical diagnosis of normal pulp/reversible pulpitis (savable pulp) or irreversible pulpitis (nonsavable pulp) is when compared with the histologic diagnosis., Methods: The study material consisted of 95 teeth collected consecutively in a general practice over a 5-year period and extracted for reasons not related to this study. Based on clinical criteria, teeth were categorized as having normal pulps, reversible pulpitis, or irreversible pulpitis. The former 2 were grouped together because they represent similar conditions in terms of prognosis. Teeth were processed for histologic and histobacteriologic analyses, and pulps were categorized as healthy, reversibly inflamed, or irreversibly inflamed according to defined criteria. The number of matching clinical/histologic diagnosis was recorded., Results: The clinical diagnosis of normal pulp/reversible pulpitis matched the histologic diagnosis in 57 of 59 (96.6%) teeth. Correspondence of the clinical and histologic diagnosis of irreversible pulpitis occurred in 27 of 32 (84.4%) cases. Infection advancing to the pulp tissue was a common finding in teeth with irreversible pulpitis but was never observed in normal/reversibly inflamed pulps., Conclusions: Findings using defined criteria for clinical and histologic classification of pulp conditions revealed a good agreement, especially for cases with no disease or reversible disease. This means that the classification of pulp conditions as normal pulps, reversible pulpitis, and irreversible pulpitis has high chances of guiding the correct therapy in the large majority of cases. However, there is still a need for refined and improved means for reliable pulp diagnosis., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Due to the real need for careful staff training in age assessment, in order to improve capacity, consistency and competence, new research on the reliability and repeatability of methods frequently used in age assessment are required. The aim of this study was twofold: first, to test the accuracy of this method for age estimation; second, to obtain data on the reliability of this technique. A sample of 81 peri-apical radiographs of upper canines (44 men and 37 women), aged between 19 and 74years, was used; the teeth were taken from the osteological collection of Sassari (Sardinia, Italy). Three blinded observers used the technique in order to perform the age estimation. The mean real age of the 81 observations was 37.21 (CI95% 34.37 40.05), and estimated ages ranged from 36.65 to 38.99 (CI95%-Ex1 35.42; 41.28; CI95%-Ex2 33.89; 39.41; CI95%-Ex3 35.92; 42.06). The module differences found by the three observers were 3.43, 4.24 and 4.45, respectively for Ex1×Ex2, Ex1×Ex3 and Ex2×Ex3. The module differences observed among real and observed ages were 2.55 (CI95% 1.90; 3.20), 2.22 (CI95% 1.65; 2.78) and 4.39 (CI95% 3.80; 5.75), respectively for Ex1, Ex2 and Ex3. No differences were observed among measurements. This technique can be reproduced and repeated after proper training, since it was found high reliability and accuracy., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Introduction: The forces applied during orthodontic treatment bring about effects on the teeth and surrounding tissues. The aim of this study was to evaluate the possible changes in the human pulpal tissue resulting from orthodontic intrusion in a 21-day period using histologic examination., Methods: The sample consisted of 17 young individuals of both sexes between the ages of 12 and 19 years. A total of 34 premolars were evaluated with orthodontic indication of extraction. Because it is a split-mouth study, in each patient, intrusion force of 60 g was applied randomly on 1 of the dental elements experimental group for 21 days. The counterpart control group received no force. After extractions, these dental elements were fixed in 10% formaldehyde, processed automatically, submitted to histotechnical preparation, and stained with hematoxylin-eosin for analysis under optical microscope., Results: The paired Fisher exact test (P ≤ .05) showed a significant increase of fibrous tissue in the experimental group. The nonparametric paired Wilcoxon test (P ≤ .05) showed a significant increase in the number of pulpal nodules in the elements of the experimental group and showed no difference in the number of blood vessels between the groups. Large-caliber vessels and congested elements were observed in 8 of the experimental group elements., Conclusions: The orthodontic intrusion force, in these conditions, caused vascular changes in the pulpal tissue and also increased the presence of fibrosis and the number of pulp calcifications in the experimental elements., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Objectives: The purpose of this study was to evaluate four in-house optimized, non-contrast enhanced sequences for MRI-investigation of maxillo-mandibular and dental structures by use of 3 T., Methods: 12 volunteers with different dental status were examined by using a 3 T MRI with a 20-channel standard head-and-neck coil. All images performed were evaluated by using 3D-techniques, with different slice-thicknesses, in 3D T1- and T2-weighted sequences, as well as by using new techniques of image depictions. In addition phantom measurements were performed to estimate the extent of image artefacts caused by retainers and metal implants., Results: Mean age of the participants was 33 years (range, 25.5-62.75 years), and the sex ratio was 5 females to 7 males. We identified different techniques to improve osseous and dental structures, despite problems caused by dental implants, tooth crowns or braces., Conclusion: The sequences evaluated offered excellent visualization in 2D and 3D of osseous and dental structures. Anatomical, osseous and dental structures were described at their ROI, in relation to patients with dental and head and neck pathologies. The ability to detect and distinguish pathological processes as soon as possible in 3D with excellent image quality avoiding ionizing radiation remains a challenging domain., (Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Statement of Problem: Information about the effect of occlusal preparation designs on the stress distribution in different ceramic crowns and the prepared tooth is limited., Purpose: The purpose of this study was to investigate the effects of anatomic and nonanatomic occlusal preparation designs on the stress distribution in ceramic crowns, teeth, and bone., Material and Methods: Finite element analysis was performed on models of a mandibular second premolar. A load of 400 N was applied to the models to test ceramic materials (In-Ceram, Empress Esthetic) and occlusal preparation (anatomic, nonanatomic) designs., Results: The lowest stress value occurred in the core material in the Empress Esthetic model prepared with the nonanatomic occlusal preparation design. In all groups, higher stress values were found to be concentrated in the lingual half of the dentin. Lower stress values were located near the apex of the pulp tissue and bony tissue that surround the root apex., Conclusions: Differences in preparation designs did not result in differences in the distribution or amount of stress in pulp, dentin, or bone. The use of different ceramic materials resulted in no differences in the amount or distribution of stress in pulp and bone. The use of a crown with a high elastic modulus led to increases in stress values in the restoration and the dentin margin, and decreases in stress values in the occlusal surface of the dentin. The nonanatomic design can be recommended as a favorable preparation design for Empress Esthetic ceramic., (Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Introduction: In regenerative endodontic treatment (RET) for immature permanent tooth, better treatment results could be obtained by applying platelet-rich plasma (PRP) as the scaffold rather than the blood clot. The goal of this study was to compare the histologic differences between using PRP and blood clot in RET., Methods: Three 6-month-old beagles each carrying 9 premolars with double root canals were randomly assigned to the PRP group, blood clot group, or negative control group. All experimental teeth suffered apical periodontitis, and RET was performed. In the blood clot group, bleeding was induced from the periapical tissues to fill the canal space. In the PRP group, autologous PRP was injected into each root canal. The animals were sacrificed 3 months later. Histologic sections were stained with hematoxylin-eosin. Statistical analysis was performed by the Fisher exact test, with the significance set at 0.05., Results: With the ingrowth of cellular cementumlike tissues, the canal wall was thickened, and the apical apex was closed in both the PRP and blood clot groups. Cementocytelike cells were present in the newly formed tissues. Meanwhile, no statistical difference was found in both experimental groups for the average percentage of apical closure, new tissue formation, and pulplike tissue formation. Noticeably, a large number of inflammatory cells were present in some root canals in both groups although the postoperative radiograph revealed the disappearance of periapical radiolucency., Conclusions: PRP application could be an option for clinical cases in which little or no bleeding were found when irritating the apical tissue during RET., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: Cone-beam computed tomographic (CBCT) imaging is a valuable tool for endodontic therapy. The aim of this study was to verify whether clinical use of CBCT imaging can accurately acquire parameters concerning molar pulp chamber landmarks, which are important data to help start a successful access cavity and avoid iatrogenic furcation perforations., Methods: Seventy CBCT images were used to measure 118 maxillary and 104 mandibular molars. The following vertical distances were measured: from the cusp tip/central fossa to the pulp chamber floor, to the pulp chamber ceiling, and to furcation; from the pulp chamber ceiling to furcation; from the pulp chamber floor to furcation; and the pulp chamber height. Measurements were read to the nearest 0.05 mm., Results: The measurements were as follows: the pulp chamber floor to furcation (maxillary molar: 1.97 ± 0.58 [mean ± standard deviation, mm], mandibular molar: 2.24 ± 0.47), the pulp chamber ceiling to furcation (maxillary molar: 4.09 ± 0.68, mandibular molar: 3.78 ± 0.70), the central fossa to furcation (maxillary molar: 8.78 ± 0.79, mandibular molar: 8.53 ± 0.65), the central fossa to the pulp chamber floor (maxillary molar: 6.81 ± 0.83, mandibular molar: 6.29 ± 0.65), the central fossa to the pulp chamber ceiling (maxillary molar: 4.69 ± 0.59, mandibular molar: 4.75 ± 0.56); and pulp chamber height (maxillary molar: 2.12 ± 0.81, mandibular molar: 1.53 ± 0.68). Measurements showing the least standard deviation were the central fossa to furcation and the central fossa to the pulp chamber floor., Conclusions: CBCT imaging may be used for precise clinical acquisition of the pulp chamber landmark measurements for molars thereby facilitating successful access cavity., (Published by Elsevier Inc.)

Odontoblasts, cementoblasts, ameloblasts, and osteoblasts all form mineralized tissues in the craniofacial complex, and all these cell types exhibit active Wnt signaling during postnatal life. We set out to understand the functions of this Wnt signaling, by evaluating the phenotypes of mice in which the essential Wnt chaperone protein, Wntless was eliminated. The deletion of Wls was restricted to cells expressing Osteocalcin (OCN), which in addition to osteoblasts includes odontoblasts, cementoblasts, and ameloblasts. Dentin, cementum, enamel, and bone all formed in OCN-Cre;Wls(fl/fl) mice but their homeostasis was dramatically affected. The most notable feature was a significant increase in dentin volume and density. We attribute this gain in dentin volume to a Wnt-mediated misregulation of Runx2. Normally, Wnt signaling stimulates Runx2, which in turn inhibits dentin sialoprotein (DSP); this inhibition must be relieved for odontoblasts to differentiate. In OCN-Cre;Wls(fl/fl) mice, Wnt pathway activation is reduced and Runx2 levels decline. The Runx2-mediated repression of DSP is relieved and odontoblast differentiation is accordingly enhanced. This study demonstrates the importance of Wnt signaling in the homeostasis of mineralized tissues of the craniofacial complex., (© 2014 American Society for Bone and Mineral Research.)

In the present global socio-political scenario, an increasing demand exists for age estimation in living persons, such as refugees and asylum seekers, who seldom have any documentation for proof of identity. Age estimation in the living poses significant challenges because the methods need to be non-invasive, accurate and ethically viable. Methods based on the analysis of the pulp chamber are recommended for age estimation in living adults. There is, however, a paucity of studies of this nature and population specific standards in Western Australia. The aim of the present study is therefore, to test the reliability and applicability of the method developed by Kvaal et al. (1995) for the purpose of developing age estimation standards for an adult Western Australian population. A total of 279 digital orthopantomograms (143 female; and 136 male) of Australian individuals were analysed. A subset of the total sample (50) was removed as a cross-validation (holdout) sample. Following the method described in Kvaal et al. (1995), length and width measurements of the tooth and pulp chamber were acquired in maxillary central and lateral incisors; second premolars, mandibular lateral incisors; canines and first premolars. Those measurements were then used to calculate a series of ratios (length and width), which were subsequently used to formulate age estimation regression models. The most accurate model based on a single tooth was for the maxillary central incisor (SEE ±9.367 years), followed by the maxillary second premolar (SEE ±9.525 years). Regression models based on the measurement of multiple teeth improved age prediction accuracy (SEE ±7.963 years). The regression models presented here have expected accuracy rates comparable (if not higher than) to established skeletal morphoscopic methods. This method, therefore, offers a statistically quantified methodological approach for forensic age estimation in Western Australian adults., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

The clinical translation of stem-cell-based dental pulp regeneration will require the use of injectable scaffolds. Here, we tested the hypothesis that stem cells from exfoliated deciduous teeth (SHED) can generate a functional dental pulp when injected into full-length root canals. SHED survived and began to express putative markers of odontoblastic differentiation after 7 days when mixed with Puramatrix™ (peptide hydrogel), or after 14 days when mixed with recombinant human Collagen (rhCollagen) type I, and injected into the root canals of human premolars in vitro. Roots of human premolars injected with scaffolds (Puramatrix™ or rhCollagen) containing SHED were implanted subcutaneously into immunodeficient mice (CB-17 SCID). We observed pulp-like tissues with odontoblasts capable of generating new tubular dentin throughout the root canals. Notably, the pulp tissue engineered with SHED injected with either Puramatrix™ or rhCollagen type I presented similar cellularity and vascularization when compared with control human dental pulps. Analysis of these data, collectively, demonstrates that SHED injected into full-length human root canals differentiate into functional odontoblasts, and suggests that such a strategy might facilitate the completion of root formation in necrotic immature permanent teeth.

Age estimation is a vital aspect in creating a biological profile and aids investigators by narrowing down potentially matching identities from the available pool. In addition to routine casework, in the present global political scenario, age estimation in living individuals is required in cases of refugees, asylum seekers, human trafficking and to ascertain age of criminal responsibility. Thus robust methods that are simple, non-invasive and ethically viable are required. The aim of the present study is, therefore, to test the reliability and applicability of the coronal pulp cavity index method, for the purpose of developing age estimation standards for an adult Western Australian population. A total of 450 orthopantomograms (220 females and 230 males) of Australian individuals were analyzed. Crown and coronal pulp chamber heights were measured in the mandibular left and right premolars, and the first and second molars. These measurements were then used to calculate the tooth coronal index. Data was analyzed using paired sample t-tests to assess bilateral asymmetry followed by simple linear and multiple regressions to develop age estimation models. The most accurate age estimation based on simple linear regression model was with mandibular right first molar (SEE ±8.271 years). Multiple regression models improved age prediction accuracy considerably and the most accurate model was with bilateral first and second molars (SEE ±6.692 years). This study represents the first investigation of this method in a Western Australian population and our results indicate that the method is suitable for forensic application., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Introduction: Sodium hypochlorite (NaOCl) solutions with added wetting agents are advertised to dissolve necrotic tissue in root canals faster than their counterparts without a lowered surface tension. This was tested in the current study, and the null hypothesis formulated was that there was no difference between a commercially available NaOCl solution with a lowered surface tension (Chlor-XTRA; Vista Dental Products, Racine, WI) and a counterpart containing the same amount of available chlorine without added wetting agents regarding the soft tissue that remains in oval-shaped canals after mechanical preparation and irrigation., Methods: Formerly vital extracted teeth (N = 44, 22 pairs) with similar anatomy were radiographically paired and chemomechanically prepared. In 1 tooth from each pair, a 5.25% NaOCl solution with reduced surface tension was used; in the other, a pure, technical-grade NaOCl solution of 5.25% was used. The percentage of remaining pulp tissue (PRPT) was histologically assessed in root cross-sections. The non-Gaussian raw data were subjected to Kruskal-Wallis and Mann-Whitney U tests to verify the respective effect of the cross-section level and solution on the PRPT. The relationship between the cross-section level and the PRPT was estimated by the Spearman correlation test. The alpha-type error was set at 5%., Results: The cross-section level significantly influenced the PRPT (P < .05), whereas the PRPT was not influenced by the solution used (P > .05). A significant inverse correlation was found between the cross-section level and the PRPT (P < .05, r = -0.330). The lower the distance to the apex, the higher the PRPT regardless of the solution used., Conclusions: Contrary to the advertised statement, the dental solution with a reduced surface tension did not dissolve vital pulp tissue in oval root canals any better than a conventional NaOCl solution of similar strength. Closer to the apex, pulp tissue dissolution is less efficient irrespective of the solution., (Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: Biodentine is a new bioactive cement that is similar to the widely used mineral trioxide aggregate (MTA). It has dentin-like mechanical properties, which may be considered a suitable material for clinical indications of dentin-pulp complex regeneration such as direct pulp capping. The purpose of the present study was to compare the response of the pulp-dentin complex in human teeth after direct capping with this new tricalcium silicate-based cement with that of MTA., Methods: Pulps in 28 caries-free maxillary and mandibular permanent intact human molars scheduled for extraction for orthodontic reasons were mechanically exposed and assigned to 1 of 2 experimental groups, Biodentine or MTA, and 1 control group. Assay of periapical response and clinical examination were performed. After 6 weeks, the teeth were extracted, stained with hematoxylin-eosin, and categorized by using a histologic scoring system., Results: The majority of specimens showed complete dentinal bridge formation and an absence of inflammatory pulp response. Layers of well-arranged odontoblast and odontoblast-like cells were found to form tubular dentin under the osteodentin. Statistical analysis showed no significant differences between the Biodentine and MTA experimental groups during the observation period., Conclusions: Within the limitations of this study, Biodentine had a similar efficacy in the clinical setting and may be considered an interesting alternative to MTA in pulp-capping treatment during vital pulp therapy., (Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Objectives: This study uses a fluid-structure interaction (FSI) simulation to evaluate the fluid flow in a dental intrapulpal chamber induced by the deformation of the tooth structure during loading in various directions., Methods: The FSI is used for the biomechanics simulation of dental intrapulpal responses with the force loading gradually increasing from 0 to 100N at 0°, 30°, 45°, 60°, and 90° on the tooth surface in 1s, respectively. The effect of stress or deformation on tooth and fluid flow changes in the pulp chamber are evaluated., Results: A horizontal loading force on a tooth may induce tooth structure deformation, which increases fluid flow velocity in the coronal pulp. Thus, horizontal loading on a tooth may easily induce tooth pain., Conclusion: This study suggests that experiments to investigate the relationship between loading in various directions and dental pain should avoid measuring the bulk pulpal fluid flow from radicular pulp, but rather should measure the dentinal fluid flow in the dentinal tubules or coronal pulp. The FSI analysis used here could provide a powerful tool for investigating problems with coupled solid and fluid structures in dental biomechanics., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

A retrospective analysis of 619 upper and lower cheek teeth from 62 horses was performed. Based on clinical findings, as well as radiographic and magnetic resonance (MR) imaging findings, the teeth were classified into five groups. There were 20 teeth with abnormal MR imaging signals as well as clinical alterations and 599 healthy teeth. Using MR imaging, the appearance of pulp in diseased and disease-free teeth was compared, and the appearance of abnormal pulp was studied. Subsequently, the ability of MR imaging to diagnose pulpitis and pulp necrosis in teeth with normal external appearance was investigated. In horses with clinically verified dental disease, abnormal MR imaging findings were confirmed in the pulp of all affected teeth. An enlarged blurred pulp image with a lower signal intensity was observed only in clinically diseased teeth and was a reliable criterion for diagnosing dental disease on MR imaging. On the other hand, partial or complete absence of pulp in all MR imaging sequences was observed in both diseased and nondiseased teeth. These data demonstrate that pulp changes in equine cheek teeth can be evaluated using MR imaging., (© 2012 Veterinary Radiology & Ultrasound.)

Introduction: The purpose of this in vitro study was to evaluate and compare the efficacy and safety of different devices available for canal cleansing., Methods: The following systems were tested: passive ultrasonic irrigation, EndoVac (Discus Dental, Culver City, CA), and the irrigation ultrasonic needle (ProUltra PiezoFlow Irrigation Ultrasonic Needle; Dentsply Tulsa Dental Specialties, Tulsa, OK) used in both the injection mode (IUNI) and the aspiration mode (IUNA). In the control group, traditional irrigation with a syringe and side-vented needle was used. A resin model was used with 4 lateral canals (respectively at 2, 5, 8, and 11 mm from the apical foramen) filled with bovine pulp stained with fuchsin. The model also included a 2-mm chamber in communication with the apex, again filled with bovine pulp, which enabled the measurement of the extrusion of NaOCl beyond the apex., Results: With regard to efficacy, the most effective systems were found to be those using the ultrasonic needle, either in aspiration or injection modes; EndoVac was the least effective. Conversely, IUNI was found to bring the highest risk with regard to the extrusion of sodium hypochlorite beyond the apex. EndoVac was the safest but only by a slight margin compared with IUNA and passive ultrasonic irrigation., Conclusions: Based on this study, the system that best reconciles efficacy and safety appears to be IUNA., (Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this study was to determine whether ultrashort echo time magnetic resonance imaging technology could be used to image teeth with orthodontic appliances in place., Methods: High-resolution 3-T ultrashort echo time magnetic resonance imaging was performed on 60 extracted premolars with fixed ceramic orthodontic appliances (Clarity, 3M Unitek, Monrovia, Calif; Radiance, American Orthodontics, Sheboygan, Wis; and Ice, Ormco, Glendora, Calif). The teeth were collected from the orthodontic clinic at the University of Alabama at Birmingham, and the institutional review board of the University of Alabama at Birmingham approved the study. Linear measurements of tooth morphology and orthodontic bracket dimensions were acquired with calipers and compared with virtual digital magnetic resonance imaging. The spin echo and high spatial resolution multi-slice turbo spin echo were only used for visual comparison with the ultrashort echo time slices. Both the caliper and the ultrashort echo time magnetic resonance imaging measurements were highly reliable and accurate. Comparisons between the 2 methods showed no statistically significant differences in any bracket or tooth dimensions, with a P value of >0.05. In general, the differences in the values ranged from -0.01 to 0.06 mm. A visual evaluation scale was used to assess the quality of the ultrashort echo time magnetic resonance images when assessing the delineation of dental hard tissues., Results: The visual evaluation scale of the images showed that enamel, dentin, pulp, and ceramic orthodontic appliances could be subjectively delineated at a high level with the ultrashort echo time magnetic resonance imaging., Conclusions: The following conclusions can be drawn from this prospective study. Ceramic orthodontic appliances, without metal components, cause no dental image distortions and are readily visible on the ultrashort echo time magnetic resonance imaging scans. The measurements comparing linear tooth measurements with virtual digital magnetic resonance images demonstrated that magnetic resonance imaging has statistically and clinically significant accuracy on external tooth and bracket measurements. Visual evaluation of the images showed that enamel, dentin, pulp, and ceramic orthodontic appliances could be subjectively delineated at a high level with ultrashort echo time magnetic resonance imaging. Metallic slots in ceramic appliances cause severe image distortions. These distortions are localized and should not affect surrounding tissues in full-volume magnetic resonance imaging., (Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Objectives: Pulpal response to tooth preparation is a major concern in fixed prosthodontics. Research has suggested that 2mm or more of remaining dentine is critical in protecting the pulp following tooth preparation. However, clinicians have no means of knowing dentine thickness either before or after preparation and therefore lack feedback about this important aspect of preparation quality. The aim of this project was to develop a method for measuring local dentine thickness following tooth preparation for metal ceramic crowns, in vitro, which could be used as a tool to evaluate preparation technique and instrumentation., Methods: Microtomography (XMT or micro-CT) scans were taken of extracted teeth before and after crown preparation. Local dentine thickness was defined for every voxel within the 3D tooth image as the sum of distances from that voxel to the pulp and to the anatomical surface. The method also allows the thickness of material removed to be quantified. Three-dimensional colour-coded maps of dentine thickness were generated, and the distributions of dentine thickness throughout the teeth were analysed. This was tested by a single operator on sixteen extracted upper central incisors., Results: This method enabled clear visualisation and analysis of residual dentine thickness. In the trial, it revealed consistent over-prepared regions along the labial proximal line angles which, in a clinical case, could affect subsequent tooth and restoration longevity. All but one of the prepared teeth had regions with a residual dentine thickness of less than 1.5mm, in 6 it was less than 1.0mm and in 3 of these it was less than 0.5mm., Conclusion: Although ex vivo, this method can be used as a research tool to look for patterns of over- or under-preparation, leading to possible modification of technique, instrumentation and, or crown design., Clinical Significance: It is not currently possible for clinicians to know the thickness of residual dentine following crown preparation, a key factor in long term outcome. The described method of quantifying and visualising this thickness allows preparation techniques and instrumentation to be evaluated in vitro, leading to prospective improvements in clinical procedures., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Objectives: Root resorption is a ubiquitous although undesirable sequela to orthodontic treatment. Current methods to investigate the pathophysiology have certain limitations. In pursuit to understand and develop treatment modalities for orthodontically induced root resorption, the ability to manipulate cells within their natural extracellular matrix in a three dimensional organotypic model is invaluable. The study aimed to develop a laboratory-based organotypic model to investigate the effect of orthodontic forces on the periodontium., Methods: Mandibular slices of male Wistar rats were maintained in Trowel-typed cultures at 37°C in 5% carbon dioxide in air for 7 days with test specimens subjected to compressive forces at 50 g and 100g by stainless steel springs. Tissue architecture and cell viability were maintained under culture conditions., Results: Osteoclast numbers increased significantly in both test groups whilst odontoclasts increased in the 50 g group. Immunohistochemistry demonstrated increased dentine sialoprotein expression in both test groups, suggesting changes in mineralization-related activity due to mechanical strain., Conclusion: The study showed initial cellular and molecular changes of key markers that relate to root resorption in response to mechanical loading., Clinical Significance: Severe root resorption may occur when forces applied are heavy or transmitted over an extended period and could lead to mobility and tooth loss. This ex vivo model can be used to investigate cellular and molecular processes during orthodontic tooth movement which may advance the clinical management of root resorption., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Context: During fixed orthodontic therapy, when the stress levels in the periodontal ligament (PDL) exceedsan optimum level, it could lead to root resorption., Aims: To determine an apical stress incident on the maxillary central incisor during tooth movement with varying cemental and periodontal ligament thickness by Finite Element Method (FEM) modeling., Settings and Design: A three dimensional finite element model of a maxillary central incisor along with enamel, dentin, cementum, PDL and alveolar bone was recreated using EZIDCOM and AUTOCAD software. ALTAIR Hyper mesh 7.0 version was used to create the Finite Element meshwork of the tooth. This virtual model was transferred to Finite Element Analysis software, ANSYS where different tooth movements were performed., Materials and Methods: Cemental thickness at the root apex was varied from 200 μm to 1000 μm in increments of 200 μm. PDL thickness was varied as 0.24 mm and 0.15 mm. Intrusive, Extrusive, Rotation and Tipping forces were delivered to determine an apical stress for each set of parameters., Results: Results indicated that an apical stress induced in the cementum and PDL, increased with an increase in cementum and PDL thickness respectively. Apical stress induced in the cementum remained the same or decreased with an increase in the PDL thickness. Apical stress induced in the PDL decreased with an increase in the cementum thickness., Conclusion: The study concluded that the clinical delivery of an orthodontic forces will cause stress in the cementum and PDL. Hence, it is necessary to limit the orthodontic force to prevent root resorption.

Aim: To compare the effectiveness of two rotary hybrid instrumentation techniques with focus on apical enlargement in molar teeth and to quantify and visualize spatial details of instrumentation efficacy in root canals of different complexity., Methodology: Maxillary and mandibular molar teeth were scanned using X-ray microcomputed tomography. Root canals were prepared using either a GT/Profile protocol or a RaCe/NiTi protocol. Variables used for evaluation were the following: distance between root canal surfaces before and after preparation (distance after preparation, DAP), percentage of root canal area remaining unprepared and increase in canal volume after preparation. Root canals were classified according to size and complexity, and consequences of unprepared portions of narrow root canals and intraradicular connections/isthmuses were included in the analyses. One- and two-way anova were used in the statistical analyses., Results: No difference was found between the two techniques: DAP(apical-third) (P = 0.590), area unprepared(apical-third) (P = 0.126) and volume increase(apical-third) (P = 0.821). Unprepared root canal area became larger in relation to root canal size and complexity, irrespective of the technique used. Percentage of root canal area remaining unprepared was significantly lower in small root canals and complex systems compared to large root canals. The isthmus area per se contributed with a mean of 17.6%, and with a mean of 25.7%, when a narrow root canal remained unprepared., Conclusions: The addition of isthmuses did not significantly alter the ratio of instrumented to unprepared areas at total root canal level. Distal and palatal root canals had the highest level of unprepared area irrespective of the two instrumentation techniques examined., (© 2011 International Endodontic Journal.)