Objectives: The aim of this in-vitro study was to assess the performance of a newly introduced fl... more Objectives: The aim of this in-vitro study was to assess the performance of a newly introduced fluorescence method for the detection of dentin caries. Methods: 53 freshly extracted human permanent teeth were available for the study. Informed consent was obtained from patients prior to extraction about the use of teeth for research purposes. Two examiners examined 99 investigation sites on the occlusal surfaces of the teeth using the fluorescence camera VistaProof (VP). Each investigation site was measured independently in a random order twice within one day. The teeth were then serially sectioned for assessment of lesion depth. Results: Intra-class-correlation coefficients (ICC) for intra- and inter-examiner reproducibility were calculated. For further analyses, the mean values of both examiners for the fluorescence readings were used. The relationship between the VP and the histological scoring system was assessed using the Spearman rank correlation coefficient. Sensitivity, specif...
Clinical Relevance Ceramic inlays as aesthetic restorations in the posterior region can be used s... more Clinical Relevance Ceramic inlays as aesthetic restorations in the posterior region can be used successfully in routine clinical therapy. Cement viscosity, the operator (experienced dentist vs dental student) and the number of surfaces have no influence on longevity.
Histological sectioning is a generally accepted in vitro validation method for caries detection t... more Histological sectioning is a generally accepted in vitro validation method for caries detection techniques. However, it requires cumbersome sample preparation and induces irreversible sample destruction. Micro-Computer Tomography (micro-CT) allows non-destructive imaging of tooth structure. The aim of this study was to compare the performance of histological sectioning and micro-CT imaging in detecting approximal carious lesions. Unlike previous studies, evaluation is objectified by comparing visual appearance of exactly corresponding anatomical regions. Sixty extracted human teeth were scanned with a desktop micro CT system. Axial histological slices were prepared and photographed. Sample preparation, combined with dedicated image processing, ensured selection of identical anatomical regions on radiographic and histological images. Evaluation of the presence and extent of carious lesions was performed by four dentists using custom-designed software. Each section was scored independ...
Undecalcified teeth with enamel and dentin cannot be sectioned with conventional histological pro... more Undecalcified teeth with enamel and dentin cannot be sectioned with conventional histological procedures due to the risk of section damage. The reported workshop presents a step by step account of the histological preparation of undecalcified sections of teeth starting with dehydration of the teeth and finally ending with the coverslipped section on a histologic slide. The sawing technique allows to cut sections down to ~150-200 μm and to grind them down to 10-100 μm in a further step. To produce digital images of the slides an adapted macro photography technique is used based on a macroscope with a wide image field. These technologies provide answers for many histologically based clinical and experimental questions like morphology of teeth, caries diagnostics, restorative procedures and endodontics.
Zusammenfassung: Der Tastsinn spielt in der Endodontie zur Erfassung dreidimensionaler Strukturen... more Zusammenfassung: Der Tastsinn spielt in der Endodontie zur Erfassung dreidimensionaler Strukturen eine wichtige Rolle. In der vorliegenden Arbeit sollte untersucht werden, ob die taktile Erfassung von Kanalverläufen durch die Ausbildungsdauer, die verwendeten Instrumente oder die initial erlernte Aufbereitungstechnik beeinflusst werden. Insgesamt 72 Studierende des 6. und 56 des 10. Fachsemesters (FS) ertasteten mit vier unterschiedlichen Handinstrumenten zwölf artifizielle Kanäle mit geradem, gekrümmtem, s-förmigem sowie Typ IV-Kanalverlauf in randomisierter Reihenfolge. Studierende des 6. FS konnten signifikant (p \u3c 0,01) seltener die richtige Konfiguration ertasten, als Studierende des 10. FS. Initiales Erlernen der manuellen oder der maschinellen Aufbereitung hatte keinen signifikanten Einfluss (p \u3e 0,05). Im 6. FS konnten mit Flexicut und NiTi-Feilen signifikant (p \u3c 0,01) häufiger die korrekten Konfigurationen ertastet werden, als mit der Hedström- bzw. K-Feilen. Gerade Kanäle wurden im sowohl im 6. als auch im 10. FS am besten, Typ IV-Kanäle dagegen am schlechtesten erkannt (p \u3c 0,001). Sowohl die Ausbildungsdauer, als auch die Auswahl der Instrumente beeinflussen die korrekte Erfassung der Kanalkonfigurationen signifikant; demgegenüber hatte die Reihenfolge der Ausbildungsschritte keinen Einfluss auf die Kanalformerkennung in der vorliegenden Arbeit. Tactile assessment of artificial root canal geometry by students Summary: Tactile sensitivity plays an important role in determining three-dimensional structures in endodontics. The aim of this study was to examine whether tactile assessment of root canals was affected by the training period, the instruments used or the preparation technique first learned by students. A total of 72 third-year dental students and 56 fifth-year dental students assessed twelve artificial root canals with straight, curved, S-shaped and Type IV root canal configurations in a randomized order using four different manual instruments. Third-year students were significantly (p \u3c 0.01) less successful in determining the correct configuration than fifth-year students. Learning the manual or the rotary technique first did not have any significant influence (p \u3e 0.05). Third-year students were significantly more (p \u3c 0.01) successful in determining the correct configuration with Flexicut and NiTi files than with Hedström or K-files. Straight canals were most easily recognized by both third-year and fifth-year students with Type IV canals being the most difficult to recognize (p \u3c 0.001). Both the training period and the choice of instruments significantly influenced correct assessment of the canal configurations; on the other hand the sequence of training stages did not have any influence on recognition of the canal configuration in this study
Objectives: In dentistry, images of teeth with sound and carious surfaces are often used as a too... more Objectives: In dentistry, images of teeth with sound and carious surfaces are often used as a tool for training purposes in the cariology curriculum. This study aimed to evaluate the diagnostic performance of the visual scoring system ICDAS (International Caries Detection and Assessment System) for detection of dental caries applied by undergraduate students when digitally optimized images of extracted teeth are used.
The aim of this study was to investigate the influence of the preparation taper on the apical lea... more The aim of this study was to investigate the influence of the preparation taper on the apical leakage of 4 different root canal obturation techniques. A total of n = 165 human straight teeth roots were divided to groups of 15 each and prepared using rotating Ni/Ti and hand instruments to ISO 40 and tapers of 0.02, 0.04 and 0.06. The roots were filled using a central cone technique, lateral condensation, vertical condensation and continuous wave technique (System-B® and Obtura®). The roots were blinded and coated with nail varnish except 1mm above the apex. After immersion in methylene blue, five sections of 0.8 mm step length were done in the apical region. All roots were then cut at a point 6 mm above the apex. The residual root was then exposed to a second dye immersion. Three serial cuts were done in this middle part of the roots. All cuts were digitised. Penetration depth and penetration degree around the root filling were calculated for the middle part of the root and the apical region separately. Results were compared using MANOVA and a significance level of p = 0.05. There was no influence of taper on penetration depth (p = 0.42), apical penetration degree (p = 0.535) or mid root penetration degree (p = 0.054). We found no influence of the filling method on apical penetration degree (p = 0.141) but highly significant influence on the mid root penetration degree (p < 0.001) and the apical penetration depth (p<0.001). The combination of taper and filling method showed a significant influence on apical penetration degree (p = 0.013) and depth (p = 0.031) but no significant influence in the middle part of the root (p = 0.539). The quality of root canal obturation depends on the combination of preparation taper and filling method. The single cone technique shows best results using a taper of 0.02. For lateral condensation technique a taper of 0.04 seems to be more optimal. Vertical condensation techniques perform independently of the preparation taper. None of the filling methods performed superior to the others
Objectives: The aim of this in-vitro study was to assess the performance of a newly introduced fl... more Objectives: The aim of this in-vitro study was to assess the performance of a newly introduced fluorescence method for the detection of dentin caries. Methods: 53 freshly extracted human permanent teeth were available for the study. Informed consent was obtained from patients prior to extraction about the use of teeth for research purposes. Two examiners examined 99 investigation sites on the occlusal surfaces of the teeth using the fluorescence camera VistaProof (VP). Each investigation site was measured independently in a random order twice within one day. The teeth were then serially sectioned for assessment of lesion depth. Results: Intra-class-correlation coefficients (ICC) for intra- and inter-examiner reproducibility were calculated. For further analyses, the mean values of both examiners for the fluorescence readings were used. The relationship between the VP and the histological scoring system was assessed using the Spearman rank correlation coefficient. Sensitivity, specif...
Clinical Relevance Ceramic inlays as aesthetic restorations in the posterior region can be used s... more Clinical Relevance Ceramic inlays as aesthetic restorations in the posterior region can be used successfully in routine clinical therapy. Cement viscosity, the operator (experienced dentist vs dental student) and the number of surfaces have no influence on longevity.
Histological sectioning is a generally accepted in vitro validation method for caries detection t... more Histological sectioning is a generally accepted in vitro validation method for caries detection techniques. However, it requires cumbersome sample preparation and induces irreversible sample destruction. Micro-Computer Tomography (micro-CT) allows non-destructive imaging of tooth structure. The aim of this study was to compare the performance of histological sectioning and micro-CT imaging in detecting approximal carious lesions. Unlike previous studies, evaluation is objectified by comparing visual appearance of exactly corresponding anatomical regions. Sixty extracted human teeth were scanned with a desktop micro CT system. Axial histological slices were prepared and photographed. Sample preparation, combined with dedicated image processing, ensured selection of identical anatomical regions on radiographic and histological images. Evaluation of the presence and extent of carious lesions was performed by four dentists using custom-designed software. Each section was scored independ...
Undecalcified teeth with enamel and dentin cannot be sectioned with conventional histological pro... more Undecalcified teeth with enamel and dentin cannot be sectioned with conventional histological procedures due to the risk of section damage. The reported workshop presents a step by step account of the histological preparation of undecalcified sections of teeth starting with dehydration of the teeth and finally ending with the coverslipped section on a histologic slide. The sawing technique allows to cut sections down to ~150-200 μm and to grind them down to 10-100 μm in a further step. To produce digital images of the slides an adapted macro photography technique is used based on a macroscope with a wide image field. These technologies provide answers for many histologically based clinical and experimental questions like morphology of teeth, caries diagnostics, restorative procedures and endodontics.
Zusammenfassung: Der Tastsinn spielt in der Endodontie zur Erfassung dreidimensionaler Strukturen... more Zusammenfassung: Der Tastsinn spielt in der Endodontie zur Erfassung dreidimensionaler Strukturen eine wichtige Rolle. In der vorliegenden Arbeit sollte untersucht werden, ob die taktile Erfassung von Kanalverläufen durch die Ausbildungsdauer, die verwendeten Instrumente oder die initial erlernte Aufbereitungstechnik beeinflusst werden. Insgesamt 72 Studierende des 6. und 56 des 10. Fachsemesters (FS) ertasteten mit vier unterschiedlichen Handinstrumenten zwölf artifizielle Kanäle mit geradem, gekrümmtem, s-förmigem sowie Typ IV-Kanalverlauf in randomisierter Reihenfolge. Studierende des 6. FS konnten signifikant (p \u3c 0,01) seltener die richtige Konfiguration ertasten, als Studierende des 10. FS. Initiales Erlernen der manuellen oder der maschinellen Aufbereitung hatte keinen signifikanten Einfluss (p \u3e 0,05). Im 6. FS konnten mit Flexicut und NiTi-Feilen signifikant (p \u3c 0,01) häufiger die korrekten Konfigurationen ertastet werden, als mit der Hedström- bzw. K-Feilen. Gerade Kanäle wurden im sowohl im 6. als auch im 10. FS am besten, Typ IV-Kanäle dagegen am schlechtesten erkannt (p \u3c 0,001). Sowohl die Ausbildungsdauer, als auch die Auswahl der Instrumente beeinflussen die korrekte Erfassung der Kanalkonfigurationen signifikant; demgegenüber hatte die Reihenfolge der Ausbildungsschritte keinen Einfluss auf die Kanalformerkennung in der vorliegenden Arbeit. Tactile assessment of artificial root canal geometry by students Summary: Tactile sensitivity plays an important role in determining three-dimensional structures in endodontics. The aim of this study was to examine whether tactile assessment of root canals was affected by the training period, the instruments used or the preparation technique first learned by students. A total of 72 third-year dental students and 56 fifth-year dental students assessed twelve artificial root canals with straight, curved, S-shaped and Type IV root canal configurations in a randomized order using four different manual instruments. Third-year students were significantly (p \u3c 0.01) less successful in determining the correct configuration than fifth-year students. Learning the manual or the rotary technique first did not have any significant influence (p \u3e 0.05). Third-year students were significantly more (p \u3c 0.01) successful in determining the correct configuration with Flexicut and NiTi files than with Hedström or K-files. Straight canals were most easily recognized by both third-year and fifth-year students with Type IV canals being the most difficult to recognize (p \u3c 0.001). Both the training period and the choice of instruments significantly influenced correct assessment of the canal configurations; on the other hand the sequence of training stages did not have any influence on recognition of the canal configuration in this study
Objectives: In dentistry, images of teeth with sound and carious surfaces are often used as a too... more Objectives: In dentistry, images of teeth with sound and carious surfaces are often used as a tool for training purposes in the cariology curriculum. This study aimed to evaluate the diagnostic performance of the visual scoring system ICDAS (International Caries Detection and Assessment System) for detection of dental caries applied by undergraduate students when digitally optimized images of extracted teeth are used.
The aim of this study was to investigate the influence of the preparation taper on the apical lea... more The aim of this study was to investigate the influence of the preparation taper on the apical leakage of 4 different root canal obturation techniques. A total of n = 165 human straight teeth roots were divided to groups of 15 each and prepared using rotating Ni/Ti and hand instruments to ISO 40 and tapers of 0.02, 0.04 and 0.06. The roots were filled using a central cone technique, lateral condensation, vertical condensation and continuous wave technique (System-B® and Obtura®). The roots were blinded and coated with nail varnish except 1mm above the apex. After immersion in methylene blue, five sections of 0.8 mm step length were done in the apical region. All roots were then cut at a point 6 mm above the apex. The residual root was then exposed to a second dye immersion. Three serial cuts were done in this middle part of the roots. All cuts were digitised. Penetration depth and penetration degree around the root filling were calculated for the middle part of the root and the apical region separately. Results were compared using MANOVA and a significance level of p = 0.05. There was no influence of taper on penetration depth (p = 0.42), apical penetration degree (p = 0.535) or mid root penetration degree (p = 0.054). We found no influence of the filling method on apical penetration degree (p = 0.141) but highly significant influence on the mid root penetration degree (p < 0.001) and the apical penetration depth (p<0.001). The combination of taper and filling method showed a significant influence on apical penetration degree (p = 0.013) and depth (p = 0.031) but no significant influence in the middle part of the root (p = 0.539). The quality of root canal obturation depends on the combination of preparation taper and filling method. The single cone technique shows best results using a taper of 0.02. For lateral condensation technique a taper of 0.04 seems to be more optimal. Vertical condensation techniques perform independently of the preparation taper. None of the filling methods performed superior to the others
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