Physiologic Exfoliation Research Articles

Evaluation of Mechanical Versus Manual Root Canal Preparation in Primary Molars-A Comparative In Vitro Study.

The endodontic treatment of primary teeth is to maintain the function of the tooth free of symptoms until its physiological exfoliation. A critical factor for success is how quickly and effectively the root canal preparation can be performed. Therefore, the aim of this comparative in vitro study was to analyze the efficiency of two mechanical root canal preparation systems FM (FlexMaster) and HF (HyFlex EDM) to manual KF (K-file) on extracted primary molars. A total of 45 teeth were divided into three groups (n = 15): KF (#15-35), FM (04#30) and HF (25/~ OneFile). Root canal preparation was performed, and the preparation time was measured. All root canals were non-destructively analyzed by micro-computed tomography in the cervical, middle and apical thirds before and after preparation with regard to the parameters of canal transport (in μm) and centering ratio (0-1). Statistical analysis was performed at a 5% significance level using non-parametric tests. HF caused the lowest canal transport in the apical third (p = 0.008). The centering ratio value of HF was significantly higher in the middle third of the root canals than in the other two groups (p < 0.01). The mean instrumentation time was significantly higher for KF (6.67 min) than for FM (4.69 min) and HF (4.03 min, p < 0.01). HF can be recommended for primary molar root canal treatment.

Ихтиоздың сирек кездесетін клиникалық түрі - бір жақтық ихтиозформалы эритродермия: Клиникалық жағдай

Congenital ichthyosis is one of the hereditary dermatoses that develop due to a violation of the keratinization process. The clinical manifestation of ichthyosis is characterized by dryness of the skin during physical examination and scaling of different degrees of clarity. Congenital ichthyosis can be classified as one of the most difficult and urgent problems in the field of dermatology and pediatrics due to the fact that the pathogenesis of this pathology is not fully studied, its persistent course, and the difficulty of achieving positive treatment results.In addition, despite many common features, types of ichthyosis are distinguished based on clinical and histological appearance: simple ichthyosis, recessive X-doubled ichthyosis, classic lamellar ichthyosis, bullous and non-bullous congenital ichthyosiform erythroderma. In all these types of ichthyosis, there is a violation of cellular kinetics and their physiological exfoliation process, resulting in excessive keratinization of the skin in the primary manifestation. During ichthyosis, there is a violation of the barrier function of the skin, loss of water between the epidermis and inability of the skin to retain moisture. In this article, we have shared a patient with these symptoms who was diagnosed with unilateral ichthyosiform erythroderma, one of the rare forms of ichthyosis encountered in our practice. This article is informative for general practitioners, neonatologists, pediatricians, dermatovenerologists and geneticists.

TOOTH BANKING OR DENTAL STEM CELL BANKING &amp; ITS ROLE IN PEDIATRIC DENTISTRY; LITERATUREREVIEW

Stem cell biology has become an integral part of regenerative medicine and dentistry. Since the identication of mesenchymal stem cells, stem cell biology has been a heavily explored area of regenerative medicine and tissue engineered therapies, and has become an integral part of dentistry. Stem cells from deciduous teeth are those obtained with least trauma as deciduous tooth undergoes physiologic exfoliation. Dental stem cell preservation services, “tooth banking,” focus on harvesting a child's baby teeth when they fall out naturally and preserving the stem cells from the pulp for future therapeutic use when the child needs them. The purpose of this review is to focus only on role of stem cells in paediatric dentistry and their banking

Root canal filling materials in primary teeth - review.

Inadequate treatment of endodontic infections in primary teeth results in a loss of а deciduous tooth or abnormality in the development of hard dental tissues of the permanent successor. The main goal is to maintain the integrity and health of the primary tooth until their physiological exfoliation. The success of the endodontic treatment depends on the antimicrobial activity of the root canal filling material that contributes to the elimination or reduction of the microbial infection of the root canal system. The aim of this article is to systematically review the contemporary scientific literature concerning the root canal filling materials used in primary teeth. A critical evaluation of the antimicrobial activity, as well as the advantages and disadvantages of the investigated materials, has been made. Knowledge of the composition and characteristics of the available obturating materials is a useful advantage to dentists to address the functional problems associated with endodontic infections in very young patients. Future studies should also seek and compare the long-term effects of the use of traditional and alternative intracanal materials.

Literature review on rotary endodontics in primary teeth

Primary teeth retention is of utmost importance till the occurrence of the physiological exfoliation. One of the most eminent ways of preserving a necrotic primary teeth is by performing the pulpectomy procedure. The biomechanical preparation of the canal has got a crucial role in the pulpectomy procedure. Manual method is considered to be the standard method of biomechanical preparation but still has certain drawbacks which lead to introduction of rotary instrumentation as this method is more viable and less time consuming. However, the application of rotary instrumentation technique in the pediatric dentistry is not extensive due to limited information regarding the usage of the technique in the field of pediatric dentistry. The present review focuses on rotary instrumentation and various rotary systems and their application in the pediatric dentistry.

Retained primary teeth in STAT3 hyper-IgE syndrome: early intervention in childhood is essential

BackgroundSTAT3 hyper-IgE syndrome (STAT3-HIES) is a rare primary immunodeficiency that clinically overlaps with atopic dermatitis. In addition to eczema, elevated serum-IgE, and recurrent infections, STAT3-HIES patients suffer from characteristic facies, midline defects, and retained primary teeth. To optimize dental management we assessed the development of dentition and the long-term outcomes of dental treatment in 13 molecularly defined STAT3-HIES patients using questionnaires, radiographs, and dental investigations.ResultsPrimary tooth eruption was unremarkable in all STAT3-HIES patients evaluated. Primary tooth exfoliation and permanent tooth eruption was delayed in 83% of patients due to unresorbed tooth roots. A complex orthodontic treatment was needed for one patient receiving delayed extraction of primary molars and canines. Permanent teeth erupted spontaneously in all patients receiving primary teeth extraction of retained primary teeth during average physiologic exfoliation time.ConclusionsThe association of STAT3-HIES with retained primary teeth is important knowledge for dentists and physicians as timely extraction of retained primary teeth prevents dental complications. To enable spontaneous eruption of permanent teeth in children with STAT3-HIES, we recommend extracting retained primary incisors when the patient is not older than 9 years of age and retained primary canines and molars when the patient is not older than 13 years of age, after having confirmed the presence of the permanent successor teeth by radiograph.

Avaliação da prevalência da perda precoce de molares decíduos na dentição mista

Objective: To assess primary molars early loss in mixed dentition prevalence. Method: A study was carried out in children aged 6 to 12 years. Deciduous molar loss was considered early when it occurred before Nolla stage 6 (full formed crown) of the permanent successor or one year before its physiological exfoliation. Periapical radiographs were obtained to verify the presence of the permanent successor and the level of root formation, as well as the need for placement of fixed space maintainer lingual arch or Nance button. For the study of frequency distribution of early dental loss in relation to gender and dentition, we used the Chi-square test of 5% probability level and the non-parametric Mann-Whitney test for adequate statistical analysis. Results: Of the 315 children examined, 159 (50.47%) were male and 156 (49.52%) were female. Only 25 (7.9%) presented multiple dental losses in the posterior region, 19 in the lower arch and 6 in the upper arch. In the inferior one there was predominance of first and second deciduous molars loss. There was no difference in the association between genders and the occurrence of multiple dental losses (χ² (1) = 0.03, p&gt;0.05). Conclusion: The prevalence of deciduous teeth premature loss was of 7.9% and the most affected teeth were the first and second molars in the lower arch. Lingual arch space holders were installed in 6 children, who will remain with it until the permanent successors erupt into the oral cavity.

Lesion sterilization and tissue repair in primary teeth

In primary teeth that are pulpally involved, pulp therapy is performed with the sole aim of maintaining the teeth until normal physiological exfoliation. This is to avoid any abnormalities in occlusion in the permanent dentition. However, conditions such as the presence of extensive root resorption and/or presence of furcal radiolucency may contradict pulpectomy, and in such cases, lesion sterilization and tissue repair seems to be a promising alternative to extraction followed by space maintenance.

Usage of Rotary Instruments in Root Canal Therapy of Deciduous Teeth - Review

Maintaining the deciduous teeth in the mouth until the time of physiological exfoliation is of great importance for the health of the permanent dentition. Root canal treatment, also called pulpectomy, performed in cases of inflammation or necrosis of the deciduous teeth pulp, is indicated as a successful method to preserve the tooth functionally. Conventional pulpectomy procedure is performed with stainless steel files, however, the low elasticity of these files may cause undesirable canal shapes and the time-taking treatment period may lead to deterioration of the patient's cooperation, especially in pedodontics. Ni-Ti rotary instrument systems eliminate these disadvantages and provide better quality canal fillings in a shorter duration. The present article reviewed the studies that are comparing the traditional stainless steel files and Ni-Ti rotating instrument for the root canal treatment of deciduous teeth.

Rotary Endodontics in Pediatric Dentistry: Embracing the New Alternative.

ABSTRACTPulpectomy is one of the most important procedures in maintaining the necrotic primary teeth until physiologic exfoliation. In clinical practice, time efficacy is invaluable, especially in pediatric endodontics, where unpredictability and difficulty of root canal morphology adds to a clinician's challenge. The success of a pulpectomy procedure mainly depends upon the biomechanical preparation of the root canal systems. With the advent of NiTi rotary files, adult endodontic procedures have been rendered easy, but its popularity in pedodontic practice is limited. Therefore, the purpose of this article is to review the use of NiTi rotary files for root canal instrumentation in primary teeth.How to cite this articleChauhan A, Saini S, Dua P, et al. Rotary Endodontics in Pediatric Dentistry: Embracing the New Alternative. Int J Clin Pediatr Dent 2019;12(5):460–463.

Epidemiological study of premature extraction of 5-6-year-old children from Northeastern Bulgaria

Primary teeth lost one or more years before the time of their physiological exfoliation are prematurely lost. The aim of this study is to show the percentage of prematurely extracted teeth of urban and rural children, the types of the prematurely lost teeth and the reasons for their early lost. Subject of monitoring of the epidemiological research were 1200 children (half of them are from urban regions and the other half are from rural areas) examined by strictly calibrated teams of dental specialists. The DMF (T+t) index is used to measure the dental health. We calculate the missing teeth associated with the age of the children. The teeth we considered as a prematurely lost, were extracted one and more years before the time of their physiological exfoliation. The percentage of the prematurely extracted teeth is 4,6. There was a statistically significant difference in the relative shares of the prematurely extracted teeth of the urban (3,67 %) and the rural children (5%). The second molars are the most often extracted primary teeth both of the rural children (61,67%) and the urban children (57,7%), followed by the first molars - 35,29% for the rural and 34,41% for the urban children. The canines are the most rarely prematurely extracted teeth - 2,49% (rural children), 7,7% (urban children). The main reason for the early teeth loss is the carious lesions - in 94,12% and only 5,89% - other reasons. This results demonstrates the connection between premature extraction of the primary teeth, carious activity and the need of prophylaxis.

Strategies for control and treatment of carious lesions in deciduous molars: a review of the literature

ABSTRACT In recent years, a reduction has been observed in the prevalence of dental caries in the global population. However, caries is still considered a public health problem. Currently, total removal of decayed tissue has been questioned and replaced by less invasive therapeutic approaches, which offer the possibility of incomplete removal of decayed tissue in one or two clinical sessions. Other techniques aim at sealing the carious lesion or use prefabricated metal crowns on the cavitated tooth without removal of the decayed tissue, preventing direct contact of the substrates with the carious lesion. Recently, ultra-conservative treatment has gained scientific prominence, and is able to control carious lesions through the disorganization of dental biofilm via supervised brushing. Each therapeutic approach has its advantages and limitations, and it is the responsibility of dental professionals to plan their patients' treatments according to their individual needs, allowing for better functional, aesthetic and psychological conditions for patients by preserving primary teeth until their physiological exfoliation.

Periodontal ligament stem cells modulate root resorption of human primary teeth via Runx2 regulating RANKL/OPG system.

Physiological primary teeth exfoliation is a normal phenomenon during teeth development. However, retained primary teeth can often be observed in the patients with cleidocranial dysplasia (CCD) caused by mutation of Runx2. The potential regulative mechanism is still unknown. In the present study, periodontal ligament stem cells (PDLSCs) were derived from different resorbed stages of primary teeth and permanent teeth from normal patients and primary teeth from CCD patient. The proliferative, osteogenic and osteoclast-inductive capacities of PDLSCs from each group were detected. We demonstrated here that the proliferative ability of PDLSCs was reduced while the osteogenic and the osteoclast-inductive capacity of PDLSCs were enhanced during root resorption. The results also showed that PDLSCs from permanent teeth and CCD patient expressed low level of Runx2 and RANKL while high level of OPG. However, expression of Runx2 and RANKL were increased while expression of OPG was decreased in PDLSCs derived from resorbed teeth. Furthermore, Runx2 regulating the expression of RANKL and OPG and the osteoclast-inductive capacity of PDLSCs were confirmed by gain or loss of function assay. These data suggest that PDLSCs promote osteoclast differentiation via Runx2 upregulating RANKL and downregulating OPG, leading to enhanced root resorption that results in physiological exfoliation of primary teeth.

Specialized stem cell niche enables repetitive renewal of alligator teeth

Reptiles and fish have robust regenerative powers for tooth renewal. However, extant mammals can either renew their teeth one time (diphyodont dentition) or not at all (monophyodont dentition). Humans replace their milk teeth with permanent teeth and then lose their ability for tooth renewal. Here, we study tooth renewal in a crocodilian model, the American alligator, which has well-organized teeth similar to mammals but can still undergo life-long renewal. Each alligator tooth is a complex family unit composed of the functional tooth, successional tooth, and dental lamina. Using multiple mitotic labeling, we map putative stem cells to the distal enlarged bulge of the dental lamina that contains quiescent odontogenic progenitors that can be activated during physiological exfoliation or artificial extraction. Tooth cycle initiation correlates with β-catenin activation and soluble frizzled-related protein 1 disappearance in the bulge. The dermal niche adjacent to the dermal lamina dynamically expresses neural cell adhesion molecule, tenascin-C, and other molecules. Furthermore, in development, asymmetric β-catenin localization leads to the formation of a heterochronous and complex tooth family unit configuration. Understanding how these signaling molecules interact in tooth development in this model may help us to learn how to stimulate growth of adult teeth in mammals.

Chlorhexidine increases the longevity of in vivo resin–dentin bonds

The aim of this study was to evaluate the mechanical stability of resin-dentin bonds produced in vivo in the presence of chlorhexidine. Children presenting at least one pair of contralateral primary molars with occlusal carious lesions were enrolled in the study. After cavity preparation and phosphoric acid etching, dentin was treated with 5 microl of either 2% chlorhexidine (experimental group) or deionized water (control group) [corrected].Thirteen pairs of teeth were restored and were collected after physiological exfoliation. The periods in oral function after restoration were divided as follows: up to 30 d; and 1-5, 10-12, and 18-20 months. Beam-shaped specimens (0.81 mm(2)) were obtained and subjected to microtensile bond-strength testing. A significant decrease of the bond strength was observed in the control group starting at the 1-5 month period (30.6%), while in the experimental group this decrease started only after 10-12 months of function (26.3%). The use of chlorhexidine as an adjuvant to the adhesion to dentin did not produce any detrimental effect to the immediate bond strength and was capable of reducing the rate of resin-dentin bond degradation within the first few months after restoration.

Physical, chemical, and histologic changes in dentin caries lesions of primary teeth induced by regular use of polyol chewing gums

A previous clinical trial showed that long-term use of saliva-stimulating polyol (xylitol and sorbitol) chewing gums was associated with arrest of dental caries in young subjects. After a 20-22-month intervention (when the subjects were 8 years old), a total of 23 primary teeth with extensive dentin caries lesions whose surfacein clinical examination was found to be totally rehardened (remineralized) could be removed because the teeth were near their physiologic exfoliation time. These teeth were subjected to histologic, microhardness, and electron microscopic tests. The majority of the specimens had been remineralized from the surface by a non-cellular-mediated process within the remaining collapsed, organic extracellular matrix associated with the remaining dentinal surface. Many of the underlying dentinal tubules were filled with a matrix that had been subsequently mineralized. Dental microanalyses showed that the topmost (outer) 20-mm-thick rehardened layer of the lesions exhibited the highest Ca:P ratio, which leveled off at a depth ofapproximately 150 mm. The rehardened surface layer (normally <0.1 mm in thickness) was significantly (P < 0.001) harder than sound dentin and nearly as hard as sound enamel. Although the main source of the mineral present in the rehardened layer was most likely of salivary origin, some extracellular remineralization was probably mediated by odontoblasts. The results complete the clinical diagnoses ofthe original trial and suggest that regular use of polyol chewing gums may induce changes in dentin caries lesions, which in histologic and physiochemical studies show typical characteristics of rehardening and mineralization.

Replantation des invertierten keims eines unteren zweiten prämolaren

During the initial X-ray control of a 10-year-old female orthodontic patient, a late development and an inverted position of the lower left second premolar was seen. 4.3 years later the tooth with its follicle was replanted in the upright position, preserving the second deciduous molar; at that time the root development was at an early stage. At a follow-up control 4 years after the surgical procedure the replanted tooth had erupted and the sensibility response was normal. Its root, however, although completed, could not reach the length and especially the width (in the apical half) of the contralateral premolar. This relative reduction in width seems to follow a temporary thickening of that part of the root formed during the first period after replantation. The anamnestic data suggest that physiologic exfoliation of the deciduous molar took place.