Tooth Mineralization Research Articles

An experimental study for adapting electrocoagulation as a technique for fluoride removal from water

A small amount of fluoride in potable water can maximize teeth mineralization and minimizes their cavities. However, fluoride presence in excess quantities in drinking water could cause severe illnesses including Alzheimer’s syndrome and women infertility. Thus, scholars are concerned over the last decades in developing techniques to minimizes the concentration of fluoride from wastewater and lower its impact on human health. The current research aims to utilize the electrocoagulation technique to remove the fluoride from wastewater. Experiments were conducted to study fluoride removal using rectangular electrocoagulation cell and analyze the influence of four main parameters namely detention duration, electrodes spacing, pH and current density on the performance of the electrocoagulation techniques on fluoride removal. The results showed that 93% of the fluoride was removed from the wastewater after 20 minutes of treatment using 5mm electrodes spacing with a current density of 2 mA/cm2 at a pH level of 7. The main parameters have a significant influence on the removal efficiency of the fluoride. A higher fluoride removal efficiency can be achieved in the acidic setting. The removal efficiency is positively related to the electrical current and the detention time while it is negatively related to the electrode spacing.

The association of maternal folic acid supplementation and prenatal folate and vitamin B12 concentrations with child dental development.

ObjectiveLow folic acid, folate and vitamin B12 might affect tooth formation and mineralization. The conversion of folic acid into folate is catalysed by the methylenetetrahydrofolate (MTHFR) enzyme which is encoded by the MTHFR gene. Among 3728 mothers and their 10‐year‐old children from the Generation R Study, we investigated associations of maternal folic acid supplementation and prenatal folate and vitamin B12 concentrations with child dental development. Secondly, we checked the modifying effect of MTHFR‐C677T polymorphism.MethodsInformation on folic acid supplementation was obtained by questionnaires. Concentrations of folate and vitamin B12 were measured from venous samples taken in early pregnancy. Developmental stages of teeth were defined by the Demirjian method at the age‐10 assessment. In addition, dental age of the children was calculated using the Dutch standard. GLM and multivariate linear regression models were built to study the associations.ResultsFolic acid supplementation started when pregnancy was known (β = −0.09; 95% CI: −0.17, −0.01) and folic acid supplementation started prior to known pregnancy (β = −0.12; 95% CI: −0.20, −0.04) were both associated with decelerated dental development by 1‐2 months lower dental age of 10‐year‐old children. Folate (β = −0.02, 95% CI: −0.05, 0.02) and vitamin B12 (β = 0.03, 95% CI: −0.00, 0.06) were not associated with dental age. MTHFR‐C677T did not modify the associations.ConclusionsMaternal folic acid supplementation delays dental development of children by 1‐2 months dental age, whereas maternal folate and vitamin B12 concentrations in early pregnancy do not affect the timing of child dental development.

Prevalence of first permanent molar caries and streptococcusmutans & lactobacillus level among 6- 7 year old School Children in Qassim province Kingdom of Saudi Arabia

Introduction: Dental caries is a bacterial disease of the calcified tissues of the teeth characterized by demineralization of the inorganic portion and destruction of the organic substance of the tooth and the first permanent molar the first victim of getting carious due to its early involvement. Caries has been known that is caused by bacteria fermenting food, producing acids and dissolving tooth mineral. Objective: The first permanent molars are extremely influential dental structures in maxillofacial growth and development, and in the oral health status. Aim: to assess the Prevalence of First Permanent Molar Caries Among 7-year old Children in Al-Qassim Province and its possible relation to the different levels of S. mutans (SM)and Lactobacilli (LB), salivary buffer capacity and salivary Ph. Material & Methods: a cross sectional analytical study design. With a total of 243 children, aged 6-7 year old selected from different schools randomly. Clinical examination of children was conducted to assess dental caries, and saliva was collected to assess S. mutans levels, lactobacilli, salivary PH, and buffering capacity of saliva. Results: Prevalence of carious first permanent molars was high 153 (63%). No statistically significant difference revealed by chi-square test between carious first permanent molars and Ph. A statistical significant difference was found between carious first permanent molars and saliva buffer capacity. Must patients had high buffer capacity. Chi-square test revealed that the relation between caries and SM levels was highly statistically significant at P<0.001 same thing was found in relation with LB. Children with carious first permanent molars tend to have a higher number of SM and LB in saliva than children with sound first permanent molars. Conclusion: The Prevalence of First Permanent Molar Caries Among 7-year old Children in Al-Qassim Province is high. Levels of SM and LB were also higher; this result gives an indication that there is a higher risk for those children to develop more caries in their permanent teeth in the future. Moreover, it emphasizes the importance of early intervention and educational programs, which should be implemented even before the FPMs erupt (4- to 5-year-old children).

Comparative characteristics of root formation and mineralization features in the permanent teeth according to cone beam computed tomography data

Studying features of root formation and mineralization in permanent teeth of children and adults. The root formation features were studied in 2800 children's permanent teeth aged 6-15 in Moscow and Moscow region; cone beam computed tomography was performed according to the orthodontic indications. CBCT method was also used to study the apical foramen diameter, width of the permanent teeth periodontal fissure, perform clinical examination and treatment of youngsters and young people (aged 12-25, n=180) with pulpitis (K04.03), apical periodontitis (K04.5) and uncompleted processes of hard tissues mineralization and hard tissues with different degrees of maturation; as well as groups of adults (aged 30-50, n=170) with pulpitis (K04.03) and apical periodontitis (K04.5) in permanent teeth with completed processes of hard tissues mineralization. CBCT is objective for visualizing teeth of both jaws which allows determining root formation stages in children's permanent teeth and high precision during one examination visit. Teeth Youngster's and young peopl's teeth have expressed anatomical and structural features during 5-6 years after root formation completion: apical foramen diameter of 0.71±0.004 mm, periodontal fissure width of 1.01±0.004 mm, hard tissues density in apical part of root is 12282.71 units HU, which is different from analogous readings in people over 25 where they make 0.61±0.004 mm (p<0.05); 0.71±0.003 mm (p<0.05); 1428.6±0.89 units HU (p<0.05) respectively. CBCT is a useful tool for visualization of dental roots allowing precise definition of root developmental stage in permanent teeth in children by one diagnostic imaging procedure.

Accuracy of the Chaillet's Method for Assessing the Age in Subadults. A Meta-Analysis.

Introduction Assessing the dental development plays a key role in forensic dentistry. Dental age based on stages of teeth mineralization can be assessed by using different methods, and is especially useful in subadults. Chaillet‘s method was developed based on the Demirijan’s method. In this study, we aimed to study the applicability of Chaillet‘s method in subadults. Materials and methods: We performed systematic reviews and meta-analysis of observational studies published in English using the following databases Pubmed, Web of Science, Embase and Scopus, with a timeframe between 2013 and 2019. Results: The difference between chronological age and dental age was calculated separately, for each gender. In girls, the method underestimated the age with an average difference between dental and chronological of 0.83 years (CI= [-1.34; -0.31]), with significant heterogeneity and publication bias. In boys, the method underestimated the age with an average difference between dental and chronological of 0.64 years (CI= [-1.28; 0.01)], with significant heterogeneity and publication bias. Chaillet’s method showed an advanced dental maturity in European boys by 0.35 years [-0.85; 1.55], while it underestimated the age in South Asian boys by -1.03 (CI= [-1.60; -0.46]). For girls this method showed a delayed dental development for both regions, with a rather smaller difference for Europeans of -0.06 years (CI= [0.91; 0,78]) compared to South Asian girls: -1.19 years (CI= [-1.86; -0.51. Conclusion: Dental age estimation provided by the Chaillet’s method showed an age overestimation in both genders, in most studies geographic groups.

Saliva: A Biosignature for Dental Caries

Dental caries curses major part of the world’s population; rectified as a widespread multifactorial disease. As saliva is frequently flowing fluid along the teeth and other oral structures; which plays a major role in developing and progression of dental caries. Some organic and inorganic components may protect teeth from the occurrence of dental caries. This occurs via several functions, such as clearance of food debris and sugar, aggregation and elimination of microorganisms, buffering actions to neutralize acid, maintaining concentration with respect to tooth mineral, participation in formation of the acquired pellicle and antimicrobial defence. Unassuming attestation is available on the associations between dental caries and several salivary parameters, including flow rate, buffering capacity and abundance of mutant streptococci. Despite some controversial findings, the main body of the literature supports an elevated caries prevalence and/or incidence among people with a pathologically low saliva flow rate, compromised buffering capacity and early colonization or high titer of mutant streptococci in saliva. Saliva has the potential to be used in the early detection and diagnosis of caries. This is due to the abundant biomarkers present in saliva.

Maxillary incisor enamel defects in individuals born with cleft lip/palate.

Cleft lip with or without cleft palate (CLP) is considered the most frequent congenital malformations of the head and neck, with cleft individuals exhibiting more chances of presenting abnormalities such as developmental defects of enamel (DDE). Matrix metallopeptidase 2 (MMP2) is a membrane-bound protein with collagen-degrading ability and has important roles in tooth formation and mineralization. The aim of this study was to evaluate the frequency, location, severity and extent of DDE found in the maxillary incisors for groups of individuals born with CLP, as well as understanding their relationship with the cleft side. Besides, this study addresses the hypothesis that DDE can be influenced by variation in the MMP2 genes (rs9923304). Individual samples, clinical history, intraoral photographs and panoramic radiographs were obtained from 233 patients under treatment at the Cleft Lip and Palate Service of the University Hospital Lauro Wanderley at the Federal University of Paraíba. Digital images were examined by the same evaluator using the Classification of Defects According to the Modified DDE Index, and then loaded into the Image Tool software, where two measurements were made: total area of the buccal surface (SA) and the area of the DDE (DA), obtaining the percentage of the surface area affected (%SAD) (ICC = 0.99). Genomic DNA was extracted from saliva samples from 124 participants. Genotyping was carried out using TaqMan chemistry for one marker in MMP2 (rs9923304). Statistical analyses were performed by The Jamovi Project software. The Shapiro-Wilk test was applied, followed by the Student's t-test and the Mann-Whitney test. Chi-square and Fisher's exact tests, and odds ratio (OR) with 95% confidence interval (CI) calculations were used to determine Hardy-Weinberg equilibrium and statistically significant differences with an alpha of 0.05. No significant differences in the prevalence and extent of enamel defects were found between male and female individuals born with CLP (p = 0.058256). The frequency of individuals presenting teeth with DDE, in relation to the cleft and non-cleft side, was statistically different (p <0.001; OR = 7.15, CI: 4.674> 7.151> 10.942). However, the averages of %SAD were similar (p = 0.18). The highest means of the %SAD were found in individuals with bilateral cleft lip with or without cleft palate (BCLP) when compared to individuals with unilateral cleft lip with or without cleft palate (UCLP), for the teeth inside (IA) and outside the cleft area (OA) (p <0.001). Regardless of the cleft side, individuals with BCLP were 7.85 times more likely to have more than one third of the tooth surface affected, showing more frequently defects in the three thirds (OA: p <0.001) (IA: p = 0.03), as well as a higher frequency of more than one type of defect (OA: p = 0.000358) (IA: p = 0.008016), whereas in UCLP, defects were isolated and restricted to only one third, more frequently, the incisal third (OA: p = 0.009) (IA: p = 0.001), with greater frequency of milder defects, such as demarcated (p = 0.02) and diffuse (p = 0.008) opacities. A higher frequency of the T allele, less common, was observed in the group of CLP individuals who had all the affected teeth or at least two teeth with %SAD greater than 20% (p = 0.019843). Our results suggest that MMP2 may have a role in the cases that presented DDE and genotyping rs9923304 could serve as the basis for a genomic approach to define risks for individuals born with CLP. Frequency and severity of DDE is strongly related to the CLP phenotype, since the highest values were found for BCLP. However, the extent of the DDE is independent of its relationship with the side of the cleft.

Applying Pb2+ to probe the dissolution of carbonated hydroxylapatite by Enterobacter sp.: A new insight into the bioerosion of tooth mineral.

Dental caries is one of the most common disorders in dentistry. Typically, it is caused by the dissolution of the tooth mineral due to cariogenic organisms. Bioapatite is vulnerable to acid-etching ascribed to a variety of substitutions. This study applied Pb2+ cations to probe the dissolution of synthetic carbonated hydroxylapatite (CHAp) in the acidic environment induced by Enterobacter sp. It indicated a decreasing tendency of crystallite size (from ∼400 nm to 10-20 nm) during gradual incorporation of carbonate (from 2.5 to 13.8wt %). Meanwhile, the shape of CHAp crystals was transformed from elongated to plate-like. Addition of Enterobacter sp. enhanced P release from CHAp (especially for the CHAp with ∼8wt % CO3 ) around 10 times. Moreover, the bacterium provided a moderately acidic environment to cause more formation of stable pyromorphite over other Pb-minerals, for example, Pb3 (PO4 )2 , and PbCO3 . Then, transmission electron microscopy-energy dispersive X-Ray spectroscopy mapping successfully confirmed the Pb labeling on the newly formed phosphate mineral as Pb (with high-atomic weight) has strong signal under electron microscopy. This study therefore elucidated that Pb labeling has a bright future to explore the degradation of tooth mineral by microorganisms, as well as to evaluate the resistance of calcium phosphate dental restorative materials.

X-linked Hypophosphatemic Rickets: Awareness, Knowledge, and Practice of Pediatric Endocrinologists in Arab Countries

X-linked hypophosphatemic rickets (XLHR) is a genetic disease caused by inactivating pathogenic variants in PHEX , which results in reduced mineralization of bone, teeth, and renal phosphate wasting. XLHR is traditionally treated by phosphate and vitamin D analogs. Recently, burosumab, a recombinant anti-fibroblast growth factor-23 (FGF-23) monoclonal antibody was approved as specific XLHR therapy. We aimed to assess the awareness, knowledge, and management of XLHR among members of the Arab Society for Pediatric Endocrinology and Diabetes (ASPED). Of the 97 physicians who answered the online questionnaire, 97% were aware of XLHR, and while 90% screen family members of the index case, only 29% manage children with XLHR. In children with rickets, 40% of participants measure serum/urine phosphate routinely, and 31% request serum FGF-23 in suspected XLHR cases. Almost all responders use conventional XLHR therapy, and 4% used Burosomab. Only 14% were satisfied with the conventional treatment, and 69% reported therapeutic complications in up to 25% of their patients. Multidisciplinary care for XLHR is practiced by 94%, but 82% of providers did not have transition clinics. Pediatric endocrinologists in ASPED countries are aware of XLHR but have variable practice and are unsatisfied with its conventional treatment. Raising awareness of the recognition and modern management of XLHR is needed.

Tissue-Nonspecific Alkaline Phosphatase-A Gatekeeper of Physiological Conditions in Health and a Modulator of Biological Environments in Disease.

Tissue-nonspecific alkaline phosphatase (TNAP) is a ubiquitously expressed enzyme that is best known for its role during mineralization processes in bones and skeleton. The enzyme metabolizes phosphate compounds like inorganic pyrophosphate and pyridoxal-5′-phosphate to provide, among others, inorganic phosphate for the mineralization and transportable vitamin B6 molecules. Patients with inherited loss of function mutations in the ALPL gene and consequently altered TNAP activity are suffering from the rare metabolic disease hypophosphatasia (HPP). This systemic disease is mainly characterized by impaired bone and dental mineralization but may also be accompanied by neurological symptoms, like anxiety disorders, seizures, and depression. HPP characteristically affects all ages and shows a wide range of clinical symptoms and disease severity, which results in the classification into different clinical subtypes. This review describes the molecular function of TNAP during the mineralization of bones and teeth, further discusses the current knowledge on the enzyme’s role in the nervous system and in sensory perception. An additional focus is set on the molecular role of TNAP in health and on functional observations reported in common laboratory vertebrate disease models, like rodents and zebrafish.

PREVENTION OF DENTAL CARIES IN CHILDREN WITH CEREBRAL PALSY

Abstract. Studies of the dental status of children with cerebral palsy (CP) indicate a highprevalence and intensity of damage to the teeth hard tissues.The aim is to develop a set of preventive measures against caries in children with cerebralpalsy and determine its effectiveness.Material and methods. The study included 55 children (mean age of patients was 8.4± 2.7 years) with spastic forms of cerebral palsy, which were divided into 2 groups:Group I (35 patients) – children with cerebral palsy, whom the developed set of preventivemeasures was applied to; Group II (20 children) – children with cerebral palsy, whowere given only recommendations for optimal hygienic care of the oral cavity. Allpatients underwent neurological examination, dental status, study of biochemical andimmunological parameters of oral fluid were determined.Results and discussion. Most of the examined children with cerebral palsy had spasticforms, therefore the tactics of preventive dental procedures were carried out taking intoaccount the neurological symptoms of the underlying disease. A set of treatment andprevention measures for dental caries in children with cerebral palsy was developed,which included correction of identified risk factors, correction and control of individualoral hygiene, sealing or preventive coating of fissures and blind pits of teeth and a setof local measures to normalize the teeth mineralization processes. The reduction of theincrease in the intensity of caries after the application of the proposed complex in a yearwas 53%, the reduction of the increase in the intensity of caries of permanent teeth - 30%.Conclusion. The effectiveness of the proposed complex was confirmed by a significantimprovement in oral hygiene, a decrease in acidic acid activity in the oral fluid and anincrease in alkaline phosphatase activity, an increase in the concentration of secretoryimmunoglobulin A (by 51.1%, p˂0.01).

Precision study of mineralization features of enamel apatite in the development of fluorosis by means of optical spectroscopy

We have investigated the molecular composition of the tooth enamel microregions in the normal and initial stages of the development of fluorosis by means of the IR and Raman spectroscopy. It has been shown that in the pathology of fluorosis, tooth mineralization takes place with the formation of calcium fluoroapaptite. It was found that an increased fluorine content causes a change in the characteristic profile of the bands and a redistribution of the intensity of the components of the υ1 PO4 and υ3 CO3 groups of the infrared and υ4 PO4 Raman spectra. The resulting IR and Raman spectra can be utilized as standards in the development of a new diagnostic approach of the early forms of the disease.

REVIEW ON ROLE OF METAL SALT IN THE RE-MINERALIZATION OF DENTAL CARIES

Dental caries is a most common disease that affects large number of people. It is a worldwide public health problem, affecting numerous urban and rural communities. White-spot lesions (WSL) are the earliest macroscopic evidence of enamel caries. Typically, the enamel surface layer stays intact during subsurface demineralization, but, without treatment, will eventually collapse into a full cavity. Near-neutral pH of saliva is endowed with a natural buffering capacity. Natural demineralization of tooth at an early stage is reversed by saliva, which contains calcium ions, phosphate ions, buffering agents, fluoride, and other substances. The strategy for aided remineralisation is to have ions directly delivered to where and when they are needed the most. Several mechanisms are available for aided remineralisation. The most well known is the delivery of topical and systemic fluoride, which has been proven to be a highly effective measure for prevention of caries. However limitations and risks associated with the use of fluoride as a remineralising agent fuelled the need to develop newer non-toxic techniques that deliver calcium and phosphate ions directly into subsurface lesion and/or boost remineralising properties of saliva. Encouraging microscopic changes in the demineralized enamel surface following the treatment with different concentration of metal salts, involving zinc, strontium, magnesium, in addition to stannous fluoride, many metal salts are in use for the treatment of dental caries. Microscopic examination was conducted on teeth samples before and after pH-cycling procedure and following the treatment with the selected metal salt under polarized microscope (100X). The best obvious remineralisation was found following treatment with stannous fluoride, followed by zinc chloride. The stannous fluoride was the best in the remineralisation of initial caries, results for other metals seem to be promising if used for prevention of dental caries. Mineralization of teeth is determined by major inorganic elements as calcium, phosphorous in addition to other elements that occur in traces within tooth structure (Thylstrup and Fejerskov, 1996 Murry, 1996 Peter, 2004). Fluoride now a day is widely used either systemically or topically to increase resistance of teeth surface, it has been well documented as a major contributing factor in the decline of the incidence and severity of dental caries in many countries (Murry, 1996 Curzon,1999).So far fluoride has been considered to play an almost unique role in the prevention of dental caries however there is no reason to dismiss the role of other elements as being potential cariostatic agents. Different concentrations of different metal ions as zinc and copper have been tested for better effect on remineralisation in vitro (Dedhiya, et al., 1974 Fang et al., 1980). However controversy is present in the literature concerning their effectiveness in prevention of dental caries when used topically at effective concentrations (Torredo et al., 2004 Elzbieta et al., 2008 Curzon, 1983).

The effect of application of Chlorella vulgaris extract gel on bone remodeling

Background: Chlorella vulgaris is one type of one-celled green algae, can multiply quickly, easy to cultured, and has a high survival ability. Mineral content of C.vulgaris plays a major role in bone and teeth mineralization and the regulation of blood calcium and phosphorus levels. One way to increase the effectiveness of the use of C.vulgaris in the process of bone remo-deling is to make a formulation of C.vulgaris extract in the gel form. Objective: To determine the formulation and safety of C.vulgaris gel preparations as bone remodeling material. Method: Experimental laboratory. Conclusion: the 5% concen-tration of gel preparation of C.vulgaris is the best formulation compared to other concentrations

Above or below 14years? An orthopantomographic study based on chronological course of eruption of mandibular premolars and second molars in a sample of south Indian children.

In the context of dental age assessment, two significant factors can be studied; tooth mineralisation and tooth emergence. Little is known about the role of a second molar eruption in forensic age estimation. This paper aims to contribute to forensic age estimation using an age threshold of 14years, studying the eruption stages of permanent mandibular premolars and second molars. Totally 640 orthopantomograms (OPGs) of south Indian children, aged between 10 and 18years, were evaluated using Olze et al. staging of tooth eruption stages (A-D). Spearman's rho correlation showed a strong, positive, and statistically significant correlation between the chronological age and the eruption stages of both sexes' teeth. Accuracy, sensitivity, specificity, likelihood ratios, and post-test probability values were calculated for all tested teeth. The best performance to discriminate individuals above or below 14years showed stage D in second molars. The sensitivity varied between 89% and 94% and specificity between 75% and 84%, respectively. Receiver operating characteristic curve analysis revealed high diagnostic performance for stage D, with area under the ROC curve (AUC) values of 84% and 85% for tooth 37 and 85% and 83% for tooth 47 in males and females, respectively. In conclusion, it is possible to predict age over 14years in south Indian children using tooth emergence stages from OPGs with a relatively high interobserver agreement and good diagnostic accuracy. However, there are some limitations and, therefore, must be used in conjunction with other methods.

Caries prevention due to the timing of the eruption and mineralization of permanent teeth in children environmental problems of the regions of the republic of Uzbekistan

Numerous clinical observations indicate that caries develops most intensively in the first years after teething, which coincides with the period of immature enamel. Due to the mineralization of enamel, its resistance to caries increases. The terms of eruption and mineralization of permanent teeth in school-age children with the physiological development of the child coincide with the terms of complete resorption of the roots of temporary teeth.

IMPROVING THE EFFICIENCY OF CARIES PREVENTION DUE TO THE TIMING OF THE ERUPTION AND MINERALIZATION OF PERMANENT TEETH IN CHILDREN ENVIRONMENTAL PROBLEMS OF THE REGIONS OF THE REPUBLIC OF UZBEKISTAN

The process of mineralization or maturation of enamel occurs within 3-5 years after teething. Numerous clinical observations indicate that caries develops most intensively in the first years after teething, which coincides with the period of immature enamel. Due to the mineralization of enamel, its resistance to caries increases. The terms of eruption and mineralization of permanent teeth in school-age children with the physiological development of the child coincide with the terms of complete resorption of the roots of temporary teeth.

Transcriptomic profiling of human dental pulp cells treated with tricalcium silicate-based cements by RNA sequencing.

Tricalcium silicate (TCS)-based biomaterials induce differentiation of human dental pulp cells (hDPCs) into odontoblasts/osteoblasts, which is regulated by the interplay between various intracellular pathways and their resultant secretome. The aim of this study was to compare the transcriptome-wide effects by next-generation RNA sequencing of custom-prepared hDPCs stimulated with TCS-based biomaterials: ProRoot white MTA (WMTA) (Dentsply, Tulsa; Tulsa, OK) and Biodentine (Septodont, Saint Maur des Fosses, France). Self-isolated hDPCs were seeded in a 6-well plate at a density of 5 × 105 cells per well. ProRoot white MTA and Biodentine were then placed in transwell inserts with a pore size of 0.4 μm and inserted in the well plate. RNA sequencing was performed after 3 and 7 days treatment. For post-validation, RT-PCR analyses were done on some of the RNA samples used for RNA sequencing. Our RNA sequencing results for the first time identified 7533 differentially expressed genes (DEGs) between different treatments and the number of DEGs in Biodentine was higher than ProRoot WMTA at both 3 and 7 days. Despite their differential gene expression, both the TCS-based biomaterial treatments showed gene expressions mainly involved in odontoblast differentiation, angiogenesis, neurogenesis, dentinogenesis, and tooth mineralization. The results of the present study illustrate that several important signalling pathways are induced by hDPCs stimulated with TCS-based biomaterials. The differential expression of the genes associated with odontogenesis, angiogenesis, neurogenesis, dentinogenesis, and mineralization may affect the prognosis of teeth treated with Biodentine or ProRoot white MTA.

Reliability and Variability of Metal Measurements in Permanent Tooth Enamel

Background: The enamel of permanent teeth forms in well-defined developmental periods and can be used to reconstruct early-life exposures to metals. However, little is known about how consistent metal measurements are when derived from the same tooth. We evaluated the reliability and variability of metal measurements within permanent tooth enamel to aid in its use as a biomarker for metals. Methods: Twenty-two tooth samples (4 incisors, 7 canines, 3 premolars, 4 first or second molars, 4 third molars) from the Metal Exposures and Alzheimer’s Disease Study were analyzed for aluminum (Al), arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), nickel (Ni), and zinc (Zn) using laser ablation inductively coupled plasma mass spectrometry. Up to three laser ablation lines in the enamel were analyzed per tooth. Metal levels were normalized to calcium to account for variability in tooth mineralization and log-transformed due to skewed distributions. Adjusting for tooth type, we calculated the intraclass correlation coefficient (ICC) between ablation lines in enamel capturing overall exposures and the coefficient of variation (CV) across five segments of an ablation line capturing exposures over time. Results: ICCs were greater than 0.70 for most metals: Al (0.73), As (0.99), Fe (0.96), Pb (0.95), Mn (0.85), and Ni (0.90). ICCs were lower for Cd (0.52), Cu (0.61), and Zn (0.44). CVs were highest for Cd (61-154%), between 12-30% for Mn, Ni, As, and Pb, 12-44% for Al and Fe, 35-64% for Cu, and 78-107% for Zn. Conclusions: Repeated measurements of overall exposures in enamel are consistent for most metals. Higher CVs suggest more variation in metal measurements over time. These results can facilitate using permanent teeth as a biomarker for early-life exposures to metals.

Oral Manifestations of Hyperparathyroidism and Its Management-A Review

Endocrine system is the important system of human body responsible for maintaining the homeostasis andsome other physiological functions by releasing hormones from the endocrine gland. Parathyroid glandis one of the important endocrine glandproducing parathyroid hormone. Parathyroid hormone plays animportant role in maintaining the calcium and phosphorous metabolism and has a direct influence overthe mineralization of bone and teeth. Disorders in parathyroid gland such as hyperparathyroidism andhypoparathyroidism causes altered levels of secretion of parathormone which may cause various symptomsincluding the oralmanifestations such as brown tumor, loss of bone density, increased caries occurrencerate, high risk of bone fracture etc. The aim of this article is to creating the awareness among the dentalprofessionals about the risk and preventive measures in treating the patients with hyperparathyroidism.