The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Ottmar Kullmer - One of the best experts on this subject based on the ideXlab platform.
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comparison of occlusal loading conditions in a lower Second Premolar using three dimensional finite element analysis
Clinical Oral Investigations, 2014Co-Authors: Stefano Benazzi, Ian R Grosse, Giorgio Gruppioni, Gerhard W Weber, Ottmar KullmerAbstract:This study aimed to compare the patterns of stress distribution in a lower Second Premolar using three conventional occlusal loadings and two more realistic loading scenarios based on occlusal contact areas. The teeth of a dried modern human skull were micro-CT scanned in maximum intercuspation contact with a Viscom X8060 NDT X-ray system. A kinematic analysis of the surface contacts between antagonistic right upper and lower teeth during the power stroke was carried out in the Occlusal Fingerprint Analyser (OFA) software. Stress distribution in the lower right Second Premolar was analysed using three-dimensional finite element (FE) methods, considering occlusal information taken from OFA results (cases 4–5). The output was compared to that obtained by loading the tooth with a single point force (cases 1–3). Results for cases 1–3 differ considerable from those of cases 4–5. The latter show that tensile stresses might be concentrated in grooves and fissures of the occlusal surface, in the marginal ridges, in the disto-lingual and in the distal side of the root. Moreover, the Premolar experiences high tensile stresses in the buccal aspect of the crown, supporting the idea that abfraction might be a dominant factor in the aetiology of non-carious cervical lesions. The application of FE methods in dental biomechanics can be advanced considering individual wear patterns. More realistic occlusal loadings are of importance for both new developments in prosthetic dentistry and improvements of materials for tooth restoration, as well to address open questions about the worldwide spread problem of dental failure.
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comparison of occlusal loading conditions in a lower Second Premolar using three dimensional finite element analysis
Clinical Oral Investigations, 2014Co-Authors: Stefano Benazzi, Ian R Grosse, Giorgio Gruppioni, Gerhard W Weber, Ottmar KullmerAbstract:AbstractObjectives This study aimed to compare the patterns ofstress distribution in a lower Second Premolar using threeconventionalocclusalloadingsandtwomorerealisticloadingscenarios based on occlusal contact areas.Materials and methods The teeth of a dried modern humanskull were micro-CT scanned in maximum intercuspationcontactwithaViscomX8060NDTX-raysystem.Akinematicanalysis of the surface contacts between antagonistic rightupper and lower teeth during the power stroke was carriedout in the Occlusal Fingerprint Analyser (OFA) software.Stress distribution in the lower right Second Premolar wasanalysedusingthree-dimensionalfiniteelement(FE)methods,considering occlusal information taken from OFA results(cases 4–5). The output was compared to that obtained byloading the tooth with a single point force (cases 1–3).Results Results for cases 1–3 differ considerable from thoseof cases 4–5. The latter show that tensile stresses might beconcentrated in grooves and fissures of the occlusal surface,in the marginal ridges, in the disto-lingual and in the distalside of the root. Moreover, the Premolar experiences hightensile stresses in the buccal aspect of the crown, supportingthe idea that abfraction might be a dominant factor in theaetiology of non-carious cervical lesions.Conclusions The application of FE methods in dentalbiomechanics can be advanced considering individualwear patterns.Clinical relevance More realistic occlusal loadings are ofimportance for both new developments in prosthetic dentistryandimprovementsofmaterialsfortoothrestoration,aswelltoaddress open questions about the worldwide spread problemof dental failure.Keywords Biomechanics .Loadingconditions .Occlusalwearpattern .FunctionalmorphologyIntroductionThe general morphology of the teeth can be expected toreflect a response to cope with biomechanical and functionaldemands of mastication. The high stresses produced duringmasticatory loadings (power stroke) are transmitted from theocclusal surface through the body of the tooth to the dental-supporting structure [1]. Therefore, how teeth are able towithstandthe stresses induced by mastication is important tounderstand the relation between functional demands andtooth morphology in an adaptive and evolutionary context[2–4]. This is also important in dental prosthesis and
Stefano Benazzi - One of the best experts on this subject based on the ideXlab platform.
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comparison of occlusal loading conditions in a lower Second Premolar using three dimensional finite element analysis
Clinical Oral Investigations, 2014Co-Authors: Stefano Benazzi, Ian R Grosse, Giorgio Gruppioni, Gerhard W Weber, Ottmar KullmerAbstract:This study aimed to compare the patterns of stress distribution in a lower Second Premolar using three conventional occlusal loadings and two more realistic loading scenarios based on occlusal contact areas. The teeth of a dried modern human skull were micro-CT scanned in maximum intercuspation contact with a Viscom X8060 NDT X-ray system. A kinematic analysis of the surface contacts between antagonistic right upper and lower teeth during the power stroke was carried out in the Occlusal Fingerprint Analyser (OFA) software. Stress distribution in the lower right Second Premolar was analysed using three-dimensional finite element (FE) methods, considering occlusal information taken from OFA results (cases 4–5). The output was compared to that obtained by loading the tooth with a single point force (cases 1–3). Results for cases 1–3 differ considerable from those of cases 4–5. The latter show that tensile stresses might be concentrated in grooves and fissures of the occlusal surface, in the marginal ridges, in the disto-lingual and in the distal side of the root. Moreover, the Premolar experiences high tensile stresses in the buccal aspect of the crown, supporting the idea that abfraction might be a dominant factor in the aetiology of non-carious cervical lesions. The application of FE methods in dental biomechanics can be advanced considering individual wear patterns. More realistic occlusal loadings are of importance for both new developments in prosthetic dentistry and improvements of materials for tooth restoration, as well to address open questions about the worldwide spread problem of dental failure.
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comparison of occlusal loading conditions in a lower Second Premolar using three dimensional finite element analysis
Clinical Oral Investigations, 2014Co-Authors: Stefano Benazzi, Ian R Grosse, Giorgio Gruppioni, Gerhard W Weber, Ottmar KullmerAbstract:AbstractObjectives This study aimed to compare the patterns ofstress distribution in a lower Second Premolar using threeconventionalocclusalloadingsandtwomorerealisticloadingscenarios based on occlusal contact areas.Materials and methods The teeth of a dried modern humanskull were micro-CT scanned in maximum intercuspationcontactwithaViscomX8060NDTX-raysystem.Akinematicanalysis of the surface contacts between antagonistic rightupper and lower teeth during the power stroke was carriedout in the Occlusal Fingerprint Analyser (OFA) software.Stress distribution in the lower right Second Premolar wasanalysedusingthree-dimensionalfiniteelement(FE)methods,considering occlusal information taken from OFA results(cases 4–5). The output was compared to that obtained byloading the tooth with a single point force (cases 1–3).Results Results for cases 1–3 differ considerable from thoseof cases 4–5. The latter show that tensile stresses might beconcentrated in grooves and fissures of the occlusal surface,in the marginal ridges, in the disto-lingual and in the distalside of the root. Moreover, the Premolar experiences hightensile stresses in the buccal aspect of the crown, supportingthe idea that abfraction might be a dominant factor in theaetiology of non-carious cervical lesions.Conclusions The application of FE methods in dentalbiomechanics can be advanced considering individualwear patterns.Clinical relevance More realistic occlusal loadings are ofimportance for both new developments in prosthetic dentistryandimprovementsofmaterialsfortoothrestoration,aswelltoaddress open questions about the worldwide spread problemof dental failure.Keywords Biomechanics .Loadingconditions .Occlusalwearpattern .FunctionalmorphologyIntroductionThe general morphology of the teeth can be expected toreflect a response to cope with biomechanical and functionaldemands of mastication. The high stresses produced duringmasticatory loadings (power stroke) are transmitted from theocclusal surface through the body of the tooth to the dental-supporting structure [1]. Therefore, how teeth are able towithstandthe stresses induced by mastication is important tounderstand the relation between functional demands andtooth morphology in an adaptive and evolutionary context[2–4]. This is also important in dental prosthesis and
Anoj Cherian George - One of the best experts on this subject based on the ideXlab platform.
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Endodontic management of a maxillary first and Second Premolar with three canals
Journal of conservative dentistry : JCD, 2014Co-Authors: Robin Theruvil, Chitharanjan Ganesh, Anoj Cherian GeorgeAbstract:Unusual anatomical configurations must be considered in the radiographic and clinical evaluation during the endodontic treatment. The canal anatomy maxillary first and Second Premolar has been studied extensively and the presence of three canals is relatively rare especially in the maxillary Second Premolar. The occurrence of three canals with separate foramina in both the first and Second Premolar is shown to be in extremely low percentages and has been documented as practically non-existent in Asian populations. This article describes a case of a maxillary first and Second Premolar with three canals each.
Osvaldo Zmener - One of the best experts on this subject based on the ideXlab platform.
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five canals in a mandibular Second Premolar
Journal of Endodontics, 2000Co-Authors: Elsa Macri, Osvaldo ZmenerAbstract:A case of conservative endodontic therapy for a mandibular Second Premolar with five root canals is described. A thorough knowledge of the root canal anatomy, careful interpretation of the radiographs, and access cavity modifications are essentials for enhancing intracanal procedures.
Cecilia C.s. Dong - One of the best experts on this subject based on the ideXlab platform.
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anomalous mandibular Premolars a mandibular first Premolar with three roots and a mandibular Second Premolar with a c shaped canal system
International Endodontic Journal, 2008Co-Authors: Blaine M Cleghorn, W. H. Christie, Cecilia C.s. DongAbstract:Cleghorn BM, Christie WH, Dong CCS. Anomalous mandibular Premolars: a mandibular first Premolar with three roots and a mandibular Second Premolar with a C-shaped canal system. International Endodontic Journal, 41, 1005‐1014, 2008. Aim To describe unusual variations in the root morphology and root canal systems of mandibular first and Second Premolar teeth extracted for orthodontic reasons. Summary Normally mandibular first and Second Premolar teeth have single roots with single canals. A 15-year-old patient presented for orthodontic treatment and two mandibular Premolar teeth were examined post-extraction. The mandibular first Premolar exhibited three distinct, separate roots and the mandibular Second Premolar exhibited a C-shaped root canal system. The coronal morphology of each of the mandibularPremolarsrevealeddimensionsandanatomywithinnormallimits.Theincidence of a three-rooted mandibular first Premolar is approximately 0.2%. Key learning points • Thorough clinical and radiographic interpretation is important in recognizing anomalous root and root canal systems. • The most common forms of root and canal systems and its aberrations must be understood to realize variations from normal do occur. • Successful root canal treatment requires an accurate diagnosis of the root canal system using all available aids. • Value of microcomputed tomography in the study of anatomy ex vivo and cone-beam tomography in clinical endodontics of complex Premolar cases is increasing.
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the root and root canal morphology of the human mandibular Second Premolar a literature review
Journal of Endodontics, 2007Co-Authors: Laine Clegho, W. H. Christie, Cecilia C.s. DongAbstract:The objective was to review thoroughly the literature of the root and root canal morphology of the human mandibular Second Premolar and compare the results with the mandibular first Premolar. Published studies cite the anatomy and morphology of the mandibular Second Premolar tooth for more than 7700 teeth. These studies were divided into anatomic studies reporting the number of roots, number of canals, and apical anatomy. Differences caused by gender and ethnicity have also been reported. Individual case reports of anomalies were included to demonstrate the extreme range of variation. Almost all of the teeth in the anatomic studies were single-rooted (99.6%). The incidence of 2 roots (0.3%) and 3 roots (0.1%) was extremely rare. Anatomic studies of the internal canal morphology found that a single canal was present in 91.0% of the teeth. A single apical foramen was found in 91.8% of the teeth. The incidence of more than 1 root (0.4%), more than 1 canal system (9.9%), and more than 1 foramen (8.2%) is lower than that of the mandibular first Premolar tooth (2.0%, 24.2%, and 21.1%, respectively). However, the root and root canal morphology of the mandibular Second Premolar can be extremely complex and requires careful assessment.
