Three-dimensional imaging modalities in endodontics

Mao, Teresa,Neelakantan, Prasanna Korean Academy of Oral and Maxillofacial Radiology 2014 Imaging Science in Dentistry Vol.44 No.3

Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of periradicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.

Three-dimensional imaging modalities in endodontics

Teresa Mao,Prasanna Neelakantan 대한영상치의학회 2014 Imaging Science in Dentistry Vol.44 No.3

Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions,diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.

Influence of anchors on transient cavitating flow in pipes

Rappakkaran Cherian Miji,Neelakantan Sajikumar,Kottekat Surendran Sumam 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.2

The influence of anchors on transient cavitating flow was not dealt with in detail, though there are limited studies on the effect of support on water hammer. This paper presents an experimental investigation into the influence of spacing of fixed anchors on the cavitation pressure generated in transient cavitating flows. The change in the fluid characteristics was studied along with the change in vibration of piping system. The study reveals that the occurrence of cavitation and resulting cavitation pressure are extremely influenced by the spacing of fixed anchors. As the spacing of fixed anchors is reduced; the cavitation pressure during a transient cavitating event increases severely without any change in other flow conditions while the acceleration induced on the pipe gets decreased drastically. Hence, the spacing of anchors in any piping system should be decided by balancing the lateral acceleration of the piping system and the pressure rise due to cavitation.

Dentin moisture conditions strongly influence its interactions with bioactive root canal sealers

Ozlek, Esin,Gunduz, Huseyin,Akkol, Elif,Neelakantan, Prasanna The Korean Academy of Conservative Dentistry 2020 Restorative Dentistry & Endodontics Vol.45 No.1

Objectives: It is known that bioactive materials interact with the dentin to undergo biomineralization. The exact role of moisture in this interaction is unknown. Here, we investigate the effects of dentin moisture conditions on the dislocation resistance of two bioactive root canal sealers (MTA Fillapex [Angelus Solucoes Odontologicas] and GuttaFlow BioSeal [Colténe/Whaledent AG]) at 3 weeks and 3 months after obturation. Materials and Methods: Mandibular premolars (n = 120) were prepared and randomly divided into 3 groups based on the dentin condition: group 1, dry dentin; group 2, moist dentin; group 3, wet dentin. Each group was divided into 2 subgroups for root canal filling: MTA Fillapex and GuttaFlow BioSeal. Dislocation resistance was evaluated by measuring the push-out bond strength at 3 weeks and 3 months. Failure modes were examined under a stereomicroscope. Data were statistically analyzed by Kruskal-Wallis test with a significance level of 5%. Results: Moist dentin resulted in higher bond strength values for both materials at both time points. This was significantly higher than wet and dry dentin for both the sealers at the 3 months (p < 0.05), while at 3 weeks it was significant only for GuttaFlow Bioseal. The different moisture conditions demonstrated similar trends in their effects on the dislocation resistance of the 2 root canal sealers. Conclusions: The dentin moisture conditions had a significant impact on its interaction with the bioactive materials tested. Maintaining moist dentin, but not dry or wet dentin, may be advantageous before the filling root canals with bioactive sealers.

Dentin moisture conditions strongly influence its interactions with bioactive root canal sealers

Ozlek Esin,Gündüz Hüseyin,Akkol Elif,Neelakantan Prasanna 대한치과보존학회 2020 Restorative Dentistry & Endodontics Vol.45 No.2

Objectives: It is known that bioactive materials interact with the dentin to undergo biomineralization. The exact role of moisture in this interaction is unknown. Here, we investigate the effects of dentin moisture conditions on the dislocation resistance of two bioactive root canal sealers (MTA Fillapex [Angelus Solucoes Odontologicas] and GuttaFlow BioSeal [Colténe/Whaledent AG]) at 3 weeks and 3 months after obturation. Materials and Methods: Mandibular premolars (n = 120) were prepared and randomly divided into 3 groups based on the dentin condition: group 1, dry dentin; group 2, moist dentin; group 3, wet dentin. Each group was divided into 2 subgroups for root canal filling: MTA Fillapex and GuttaFlow BioSeal. Dislocation resistance was evaluated by measuring the push-out bond strength at 3 weeks and 3 months. Failure modes were examined under a stereomicroscope. Data were statistically analyzed by Kruskal-Wallis test with a significance level of 5%. Results: Moist dentin resulted in higher bond strength values for both materials at both time points. This was significantly higher than wet and dry dentin for both the sealers at the 3 months (p < 0.05), while at 3 weeks it was significant only for GuttaFlow Bioseal. The different moisture conditions demonstrated similar trends in their effects on the dislocation resistance of the 2 root canal sealers. Conclusions: The dentin moisture conditions had a significant impact on its interaction with the bioactive materials tested. Maintaining moist dentin, but not dry or wet dentin, may be advantageous before the filling root canals with bioactive sealers.

Evaluation of biologically active secondary metabolites isolated from the toothache plant Acmella ciliata (Asteraceae)

Rahul Sharma,Arthanareeswaran Karunambigai,Somlee Gupta,Neelakantan Arumugam 경희대학교 융합한의과학연구소 2022 Oriental Pharmacy and Experimental Medicine Vol.22 No.4

Acmella ciliata (HBK) Cass. (basionym: Spilanthes ciliata HBK) is an herb of high medicinal value. Spilanthol, the prime N-alkamide in A. ciliata, is used as an active ingredient in several anti-ageing herbal tonics and in mouth washes. Here we describe quantification of spilanthol, phenolics, flavonoid and antioxidant activity in the methanol extracts prepared from flower, leaf, root and stem of the plant. HPLC of the sample extracts revealed that spilanthol was found to be maximum in flowers (18.44 mg/g), as compared to other parts of the plant as well as several of other Acmella (syn: Spilanthes) species. Estimation of phenolics and flavonoids in the extract by spectrophotometry with their values expressed respectively as equivalence of gallic acid (GAE) and quercetin (QE), revealed that phenolics content was highest in the flower extract (5.58 mg GAE/g), whereas, flavonoid content was found maximum in the leaf extract (31.65 mg QE/g). Antioxidant activity of the extract remained proportional to phenolic content of the extract. Flower extract further showed highest free radical scavenging activity in DPPH and ABTS assays, as compared to the extracts from other parts of the plant. Pearson’s correlation for antioxidant activity with respect to the phenolic and flavonoid content turned out to be positive. To the best of our knowledge this is the first report on quantification of the three secondary metabolites considered here and the antioxidant activity in the methanol extract prepared from different parts of A. cilitata.

Root canal irrigants influence the hydrophobicity and adherence of Staphylococcus epidermidis to root canal dentin: an in vitro study

Nagendrababu, Venkateshbabu,Sultan, Omer Sheriff,Kannathasan, Sreedharan,Patel, Amir Shahreza,Chitra, Ebenezer,Neelakantan, Prasanna,Davamani, Fabian The Korean Academy of Conservative Dentistry 2018 Restorative Dentistry & Endodontics Vol.43 No.1

Objectives: To determine the effect of root canal irrigants on the hydrophobicity and adherence of Staphylococcus epidermidis (S. epidermidis) to root canal dentin in vitro. Materials and Methods: Root dentin blocks (n = 60) were randomly divided into 4 groups based on the irrigation regimen: group 1, saline; group 2, 5.25% sodium hypochlorite (NaOCl); group 3, 5.25% NaOCl followed by 17% ethylenediaminetetraacetic acid (EDTA); group 4, same as group 3 followed by 2% chlorhexidine (CHX). The hydrophobicity of S. epidermidis to root dentin was calculated by cell surface hydrophobicity while the adherence was observed by fluorescence microscopy, and bacteria were quantified using ImageJ software (National Institutes of Health). Statistical analysis of the data was done using Kruskal-Wallis test and Mann-Whitney U test (p = 0.05). Results: The hydrophobicity and adherence of S. epidermidis to dentin were significantly increased after irrigating with group 3 (NaOCl-EDTA) (p < 0.05), whereas in group 4 (NaOCl-EDTA-CHX) both hydrophobicity and adherence were significantly reduced (p < 0.05). Conclusions: The adherence of S. epidermidis to dentin was influenced differently by root canal irrigants. Final irrigation with CHX reduces the bacterial adherence and may impact biofilm formation.

The effect of root canal irrigants on dentin: a focused review

Rath, Priti Pragati,Yiu, Cynthia Kar Yung,Matinlinna, Jukka Pekka,Kishen, Anil,Neelakantan, Prasanna The Korean Academy of Conservative Dentistry 2020 Restorative Dentistry & Endodontics Vol.45 No.3

Despite the vast literature on the effects of root canal irrigants on the dentin characteristics, the precise effects of clinically relevant irrigation sequences remain unclear. In this review, we systematically dissect the role of different sequential irrigation approaches that are used in clinical endodontics. Using a systematic search strategy, we attempt to answer the question: 'Which irrigating sequence has the most deleterious effects on dentin structure and properties?' The effect of irrigants on the dentin composition and mechanical properties have been reviewed. A wide variety of concentrations, duration and techniques have been employed to characterize the effects of chemicals on dentin properties, thus making it impossible to draw guidelines or recommendations of irrigant sequences to be followed clinically. It was apparent that all the studied irrigation sequences potentially result in some deleterious effects on dentin such as decrease in the flexural strength, microhardness, modulus of elasticity and inorganic content and organic-inorganic ratio of the dentin. However, the literature still lacks comprehensive investigations to compare the deleterious effect of different irrigation sequences, using a wide variety of qualitative and quantitative methods. Such investigations are essential to make clinical recommendations and strategize efforts to minimize chemically-induced damage to dentin characteristics.

Effect of cryotherapy duration on experimentally induced connective tissue inflammation in vivo

Vera Jorge,Castro-Nuñez Mayra Alejandra,Troncoso-Cibrian María Fernanda,Carrillo-Varguez Ana Gabriela,Méndez Sánchez Edgar Ramiro,Sarmiento Viviana,Lanzagorta-Rebollo Lourdes,Neelakantan Prasanna,Rome 대한치과보존학회 2023 Restorative Dentistry & Endodontics Vol.48 No.3

Objectives This study tested the hypothesis that cryotherapy duration influences lipopolysaccharide (LPS)-induced inflammation in a rat model. Materials and Methods Six Wistar rats (Rattus norvegicus albinus) were used. Five sites were selected per animal and divided into 5 groups: a negative control group (NC), 2 positive control groups (PC1 and PC2), and 2 experimental groups (E1 and E2). Cryotherapy was applied for 1 minute (E1) or 5 minutes (E2). An acute inflammatory response was induced in the PC and E groups via subcutaneous administration of 0.5 mL/kg. In the PC2 group, a catheter was inserted without additional treatment. For the E1 and E2 groups, 2.5°C saline solution was administered through the implanted catheters for 1 and 5 minutes, respectively. The rats were sacrificed, and samples were obtained and processed for histological analysis, specifically examining the presence of polymorphonuclear neutrophils and hemorrhage. The χ2 test was used to compare the presence of acute inflammation across groups. Dependent variables were compared using the linear-by-linear association test. Results Inflammation and hemorrhage varied significantly among the groups (p = 0.001). A significantly higher degree of acute inflammation was detected (p = 0.0002) in the PC and E1 samples than in the E2 group, in which cryotherapy was administered for 5 minutes. The PC and E1 groups also exhibited significantly greater numbers of neutrophils (p = 0.007), which were essentially absent in both the NC and E2 groups. Conclusions Cryotherapy administration for 5 minutes reduced the acute inflammation associated with LPS and catheter implantation. Objectives This study tested the hypothesis that cryotherapy duration influences lipopolysaccharide (LPS)-induced inflammation in a rat model. Materials and Methods Six Wistar rats (Rattus norvegicus albinus) were used. Five sites were selected per animal and divided into 5 groups: a negative control group (NC), 2 positive control groups (PC1 and PC2), and 2 experimental groups (E1 and E2). Cryotherapy was applied for 1 minute (E1) or 5 minutes (E2). An acute inflammatory response was induced in the PC and E groups via subcutaneous administration of 0.5 mL/kg. In the PC2 group, a catheter was inserted without additional treatment. For the E1 and E2 groups, 2.5°C saline solution was administered through the implanted catheters for 1 and 5 minutes, respectively. The rats were sacrificed, and samples were obtained and processed for histological analysis, specifically examining the presence of polymorphonuclear neutrophils and hemorrhage. The χ2 test was used to compare the presence of acute inflammation across groups. Dependent variables were compared using the linear-by-linear association test. Results Inflammation and hemorrhage varied significantly among the groups (p = 0.001). A significantly higher degree of acute inflammation was detected (p = 0.0002) in the PC and E1 samples than in the E2 group, in which cryotherapy was administered for 5 minutes. The PC and E1 groups also exhibited significantly greater numbers of neutrophils (p = 0.007), which were essentially absent in both the NC and E2 groups. Conclusions Cryotherapy administration for 5 minutes reduced the acute inflammation associated with LPS and catheter implantation.