Root canal morphology of primary maxillary second molars: a micro-computed tomography analysis

Abstract

BACKGROUND.The secretory acini of the adult human prostate contain basal, luminal, and intermediate types of exocrine cells. Intermediate cells are thought to play an important role in normal growth and neoplastic transformation. In this study we investigated whether this cell type is present in early stages of prostate development, using keratin antibodies specific for them. METHODS. Autoptic tissue from 11 prepubertal and 5 normal adult prostates was immunohistochemically stained with four keratin antibodies capable of specifically detecting basal, luminal, or intermediate cell types. RESULTS. Morphologically, in fetal prostate cells differentiation was often not evident. However, basally located cells usually displayed a basal-cell keratin-phenotype. Morphologically similar cells with more luminal localization expressed keratins typical of luminal cells, or of intermediate cells. CONCLUSIONS. 1) In early stages of prostate development, cells with intermediate keratinphenotype can be identified. 2) Their large numbers comply with a hierarchical pathway of cellular differentiation from basal to luminal cells. 3) The presence of intermediate cells at such an early fetal age may reflect their regulatory function in prostate development.

A critical analysis of laboratory and clinical research methods to study root and canal anatomy

“…The knowledge generated on root and canal anatomy in the primary dentition is mainly from laboratory studies using 2D radiographic imaging (Gupta & Grewal, 2005; Sarkar & Rao, 2002), staining and clearing (Bagherian et al, 2010; Gupta & Grewal, 2005; Katge & Wakpanjar, 2018), SEM (Dammaschke et al, 2004; Sharma et al, 2016), 2D radiographic (periapical [Song et al, 2009] or vertical bitewing [Liu et al, 2010; Tu et al, 2010]), CT (Zoremchhingi et al, 2005), CBCT on extracted teeth (Demiriz et al, 2018; Gaurav et al, 2013; Reddy et al, 2018) and micro‐CT (El Hachem et al, 2019; Fumes et al, 2014; Mohd Ariffin et al, 2020; Neboda et al, 2018; Wang et al, 2013; Ziya et al, 2019) (Figure 41). In addition, clinical CBCT in population groups such as Chinese (Yang et al, 2013), Korean (Jung et al, 2020), Turkey (Ozcan et al, 2016) and India (Krishnamurthy et al, 2017) have been the most commonly used methods for clinical studies.…”

“…The last decade has witnessed the use of micro‐CT in the categorisation of root and canal configuration types (Ahmed et al, 2016; El Hachem et al, 2019; Fumes et al, 2014; Mohd Ariffin et al, 2020; Neboda et al, 2018; Wang et al, 2013; Ziya et al, 2019) (Figure 42), accessory canals (El Hachem et al, 2019), in addition to 2D and 3D measurements such as root dentine thickness, canal diameter, volume, surface area, roundness and SMI (El Hachem et al, 2019; Fumes et al, 2014; Neboda et al, 2018). Similar to the permanent dentition, the use of micro‐CT has proved to be more accurate for defining minor canal details (accessory canals) in mandibular molars compared with CBCT (Acar et al, 2015).…”

Canal Transportation and Volumetric Dentin Removal Abilities of Ni-Ti Rotary File Systems in Curved Primary Root Canals: CBCT Study

“…In correlation with permanent dentition, the clinical success rate of root canal treatment in primary dentition is mainly related to perfect biomechanical preparation, the removal of microorganisms, and infected pulpal remnants from the root canal system [3]. However, complexities or variations in root canal anatomy and the high root resorption probability of primary teeth jeopardize and complicate root canal therapy (RCT) [4]. The characteristics of primary molars with curved and shorter roots, ribbon-shaped morphology, and ectopic surface resorption, especially, must be taken into consideration during RCT [5].…”

Lesion sterilization and tissue repair with chloramphenicol, tetracyline, zinc oxide/eugenol paste versus conventional pulpectomy: A 36‐month randomized controlled trial

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Primary molars have a complex anatomy with narrow, curved root canals 1,2 and interconnected isthmuses. 2 In addition, there is permeability on the pulp chamber floor caused by the thin dentin and the presence of accessory canals. 3 These morphological peculiarities, when associated with the adverse behavior of some children, add challenges in performing pulp therapies in these teeth.

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“…3 These morphological peculiarities, when associated with the adverse behavior of some children, add challenges in performing pulp therapies in these teeth. 1,2,4 To perform pulp therapies in primary molars with pulp necrosis, two techniques are indicated: pulpectomy [5][6][7] and lesion sterilization and tissue repair (LSTR). 5,7,8 The pulpectomy technique requires chemico-mechanical root canal preparation and obturation with a resorbable paste.…”