Apical limit of root canal instrumentation and obturation, Part II: A histological study

International Endodontic Journal (Impact Factor: 2.97). 12/1998; 31(6):394-409. DOI: 10.1046/j.1365-2591.1998.00183.x
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The results of an in vivo histological study involving apical and periapical tissues following root canal therapy after different observation periods demonstrated the most favourable histological conditions when the instrumentation and obturation remained at or short of the apical constriction. This was the case in the presence of vital or necrotic pulps, also when bacteria had penetrated the foramen and were present in the periapical tissues. When the sealer and/or the gutta-percha was extruded into the periapical tissue, the lateral canals and the apical ramifications, there was always a severe inflammatory reaction including a foreign body reaction despite a clinical absence of pain.

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Available from: Domenico Ricucci, Dec 25, 2013
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    • "Root Canal Therapy (RCT) depends upon complete and accurate biomechanical preparation followed by a 3D F. Koçani et al. obturation of the root canal system in the absence of injury to periapical tissues [1]. The failure of these treatments , is very often as a result of morphological variation, except the main root canal there can also present the accessory and supplementary (lateral ) canals and this is trait for every tooth [2] [3]. "
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    ABSTRACT: Aim: In this in vitro study the variation of root anatomy and canal system of the first human maxillary premolar was evaluated. Materials and Methods: Two hundred and twenty one maxillary first premolars (#221 teeth) were examined. All of the teeth were identified using the accepted criteria of Woelfel as maxillary first premolars. Selected teeth are analyzed using operating microscope (OP) and computed dental radiography (CDR). Results: There was a higher incidence of two-roots form 70.14% (n = 155), 21.72% (n = 48) had one root, and 8.14% (n = 18) had three roots. In the two-root category, 16.29% (n = 36) had bifurcation on apical third, 21.72% (n = 48) had bifurcation on middle third, and 32.13% (n = 71) had bifurcation on cervical third. The examination of root canal systems of the teeth was based on Vertucci’s classification type of canal: 64.58% (#31) of the cases had type IV (2-2-2), 25.00% (#12) type II (2-2-1), 8.33% (#4) type I (1-1-1), and 2.09% (#1) type III (1-2-1). Conclusion: This study showed a high incidence of two-rooted maxillary first premolars collected from different regions in Kosovo. Internal root canal system morphology reflects the external root anatomy. Furthermore, there is correlation between the shape of the outer surface of the root and the shape of the root canal. The cases with one root of the maxillary first premolar with a deep depression on the mesial side contain a double root canal system more often than a single cana
    Open Journal of Stomatology 07/2014; Volume 4(Number 7):332-339. DOI:10.4236/ojst.2014.47046
    • "The cemento-dentinal junction (CDJ), where the pulp and periodontal tissue meet is considered as physiological limit for working length, biomechanical preparation and obturation in endodontic treatment. This landmark cannot be precisely determined radiographically[11] and has been claimed to be determined by modern electronic apex locators with more than 90% accuracy.[12] The location of apical constriction varies from root to root, hence its relationship with CDJ is also different as CDJ could be irregular and at different height on one wall of root compare with the opposite wall.[1314] "
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    ABSTRACT: Background:Determination of correct working length is one of the keys to success in endodontic therapy.Aim:The aim of this study was to evaluate the diagnostic efficacy of various methods to determine working length of root canal.Materials and Methods:Tactile method was assessed using digital radiography and compared with electronic method using apex locator. A total sample of 30 single rooted young permanent teeth the (mandibular first premolars) with matured apices were selected for the study. Access cavity preparation was carried out. Working length was measured by tactile method using digital radiography and electronic method using apex locator with no 15 K file. Actual working length was established by grinding of cementum and dentine from the root apex and was observed under stereomicroscope. Data was collected and statistical analysis was carried out with the help of SPSS-15.Results:The results of this study showed that there was a significant difference between tactile method assessed by digital radiography and electronic method using apex locator.Conclusion:Apex locator was found to be more reliable and accurate when compared with the actual length.
    07/2014; 4(4):554-8. DOI:10.4103/2141-9248.139314
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    • "An in vivo histological study found that the most favourable histological conditions were when the instrumentation and obturation remained short of the apical constriction and that extruded gutta-percha and sealer always caused a severe inflammatory reaction despite the absence of pain (12). The problem clinicians face is how to accurately identify and prepare to this landmark – the ‘working length’ – and achieve maximum success. "
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    ABSTRACT: This study aimed to evaluate the accuracy of Root ZX in determining working length in presence of normal saline, 0.2% chlorhexidine and 2.5% of sodium hypochlorite. Sixty extracted, single rooted, single canal human teeth were used. Teeth were decoronated at CEJ and actual canal length determined. Then working length measurements were obtained with Root ZX in presence of normal saline 0.9%, 0.2% chlorhexidine and 2.5% NaOCl. The working length obtained with Root ZX were compared with actual canal length and subjected to statistical analysis. No statistical significant difference was found between actual canal length and Root ZX measurements in presence of normal saline and 0.2% chlorhexidine. Highly statistical difference was found between actual canal length and Root ZX measurements in presence of 2.5% of NaOCl, however all the measurements were within the clinically acceptable range of ±0.5mm. The accuracy of EL measurement of Root ZX within±0.5 mm of AL was consistently high in the presence of 0.2% chlorhexidine, normal saline and 2.5% sodium hypochlorite. Clinical significance: This study signifies the efficacy of ROOT ZX (Third generation apex locator) as a dependable aid in endodontic working length. Key words:Electronic apex locator, working length, root ZX accuracy, intracanal irrigating solutions.
    Journal of Clinical and Experimental Dentistry 02/2014; 6(1):e41-6. DOI:10.4317/jced.51230
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