Károly Krajczár - Academia.edu (original) (raw)
Papers by Károly Krajczár
Digital learning material. It gives a guideline to dental studies and helps them to syntetisez fr... more Digital learning material. It gives a guideline to dental studies and helps them to syntetisez from theoretic to clinical studies.
Quintessence: Publicación internacional de odontología, 2018
Objetivo: el objetivo fue investigar el valor clinico de las radiografias bidimensionales y de la... more Objetivo: el objetivo fue investigar el valor clinico de las radiografias bidimensionales y de las diferentes tecnicas de medicion radiologica a la hora de recuperar los instrumentos con una tecnica microsonica. Se trataba, asimismo, de hallar una tecnica sencilla de implementar que predijera el exito de la remocion y facilitara la valoracion del caso. De modo adicional, se valoro la calidad de la obturacion de los conductos tras la recuperacion del instrumental. Metodo y materiales: este estudio retrospectivo analizo las historias clinicas y las radiografias periapicales pre- y posoperatorias de los pacientes, las cuales se habian realizado con la tecnica del paralelismo. Sobre las radiografias preoperatorias, se midieron y compararon el angulo de acceso al canal y los angulos Schneider y Weine de la curvatura del canal. Para medir el radio de la curvatura, se utilizo el metodo Schafer. Se utilizaron las radiografias posoperatorias para valorar la conicidad, la homogeneidad y la longitud de la obturacion de los casos que tuvieron exito en la recuperacion del instrumento separado. Resultados: se investigaron 123 casos de instrumental separado. En total, se recuperaron 97 fragmentos (78,9%) con exito. Se llevo a cabo un analisis estadistico con el chi cuadrado de Pearson y el test Fisher exact (α< 0,05). La localizacion del fragmento en relacion a la curvatura del canal, el angulo de acceso y el angulo de Schneider influyeron de manera significativa en el exito. Se relaciono la mayor probabilidad de recuperacion con un angulo de acceso al canal radicular > 20 grados y un angulo de Schneider > 40 grados. Solo el 26,3% de las obturaciones cumplieron todos los estandares tecnicos establecidos. Una alterada conocidad pudo identificarse en el 64,2% de los casos y se asocio siempre a la formacion de escalones. Conclusion: la remocion microsonica trata de un metodo eficaz para recuperar los instrumentos separados. El uso de una sola tecnica de medicion radiologica sobre una radiografia periapical no resulta suficiente para valorar con precision la anatomia del canal radicular, la dificultad del caso y la probabilidad de una recuperacion exitosa. Las obturaciones posoperatorias son, en su mayor parte, de deficiente calidad.
Quintessence International, 2018
Objective: The goal was to investigate the clinical value of two-dimensional radiographs and diff... more Objective: The goal was to investigate the clinical value of two-dimensional radiographs and different radiographic measurement techniques before instrument removal with a microsonic technique. The aim was to find an easy-to-use technique for predicting the success of removal and case evaluation. Additionally the quality of root canal filling after instrument removal was assessed. Method and Materials: This retrospective study analyzed patients' records and preoperative and postoperative periapical radiographs made using the paralleling technique. On preoperative radiographs, canal access angle and Schneider and Weine angle of root canal curvature were measured and compared. The Schäfer method was used for measuring the radius of curvature. In cases of successful removal taper, homogeneity and length of obturation were evaluated on postoperative radiographs. Results: A total of 123 cases of instrument removal were investigated. In total, 97 fragments (78.9%) were removed successfully. Statistical analysis was performed with Pearson's chi-square and Fisher's exact test (α < .05). The site of fragment relative to canal curvature, canal access angle, and Schneider angle significantly influenced the success of removal. The highest chance of removal failure was associated with > 20 degrees of canal access angle and > 40 degrees of Schneider angle. Only 26.3% of obturations met all technical standards. Altered taper could be identified in 64.2% and was always associated with ledge formation. Conclusion: Microsonic removal is a successful method to retrieve separated instruments. The use of only one radiographic measurement technique is not sufficient to precisely evaluate root canal anatomy, case difficulty, and chance of successful removal before instrument removal on a periapical radiograph. Postoperative root canal fillings are mainly substandard.
Pécsi Tudományegyetem, Jun 4, 2020
Australian Endodontic Journal, Oct 18, 2018
The present report describes a case where sealer extrusion (Sealapex) occurred during root canal ... more The present report describes a case where sealer extrusion (Sealapex) occurred during root canal obturation of a left lower second premolar tooth, and the patient experienced sudden pain and followed by complete anaesthesia of the lower lip. After 3 weeks of conservative therapy and an unaltered anaesthesia period, piezosurgical removal of the extruded sealer and root-end resection was performed despite the direct contact with the mental neurovascular bundle. At suture removal, 1 week after surgery, there was no improvement in sensation. Two weeks after the operation, the patient reported some changes, including a short paraesthesia period alternating with anaesthesia. At the fourth post-operative week, neurosensory function recovered completely. This case represents successful use of the piezoelectric technique for mental nerve decompression and periapical surgery of a lower second premolar with close contact of the mental nerve.
Applied Sciences
Endodontic preparation with ultrasonic instruments can lead to temperature rise (TR) on the exter... more Endodontic preparation with ultrasonic instruments can lead to temperature rise (TR) on the external root surface (ERF), which may damage the periodontium. The aim was to measure the TR due to the ultrasonic preparation applied at different energy levels and durations during the removal of broken endodontic instrument from the root canal. Thirty-five maxillary central incisors were decoronated and 4 mm of NiTi instruments were fractured 5 mm from the most coronal part of the root. The roots were divided into seven groups according to the preparation mode (endodontic-E5, periodontal-P3) and preparation duration (30 s, 45 s, 60 s). Ultrasonic preparation was performed in periods consisting of four preparation phases with intermediate irrigations and drying. During all preparations, the TR was recorded on ERF using a K-type thermocouple. The results demonstrated that the TR measured at the end of the preparation period was higher than at baseline in all groups (p < 0.001). The large...
Dental materials : official publication of the Academy of Dental Materials, 2015
This 10-year retrospective study investigated the differences in the changes and the longevity of... more This 10-year retrospective study investigated the differences in the changes and the longevity of Class II restorations using 4 similar microhybrid resin composites (Filtek Z250, Herculite XR, Gradia Direct Posterior, Renew). Data were collected from patient records. Those patients who received posterior restoration between 2001 and 2003, and who still visited the clinical practice for regular check-up visits were selected. A total of 225 adult patients (86 males, 139 females) with 701 restorations were evaluated by 2 operators using the USPHS criteria. Data were analyzed with Fisher's Exact Test, Pearson's Chi-Square Test and Kaplan-Meier analysis (p<0.05). A failure rate of 2.1% was detected. The reasons of failures included restoration fracture, secondary caries and endodontic treatment. Similar survival rates for Gradia Direct Posterior (91.25%) and Renew (92.19%) were observed; better performance was observed with the Filtek Z250 (99.1%) and Herculite XR (98.64%). Th...
Objetivo: el objetivo fue investigar el valor clinico de las radiografias bidimensionales y de la... more Objetivo: el objetivo fue investigar el valor clinico de las radiografias bidimensionales y de las diferentes tecnicas de medicion radiologica a la hora de recuperar los instrumentos con una tecnica microsonica. Se trataba, asimismo, de hallar una tecnica sencilla de implementar que predijera el exito de la remocion y facilitara la valoracion del caso. De modo adicional, se valoro la calidad de la obturacion de los conductos tras la recuperacion del instrumental. Metodo y materiales: este estudio retrospectivo analizo las historias clinicas y las radiografias periapicales pre- y posoperatorias de los pacientes, las cuales se habian realizado con la tecnica del paralelismo. Sobre las radiografias preoperatorias, se midieron y compararon el angulo de acceso al canal y los angulos Schneider y Weine de la curvatura del canal. Para medir el radio de la curvatura, se utilizo el metodo Schafer. Se utilizaron las radiografias posoperatorias para valorar la conicidad, la homogeneidad y la lo...
Objective: To compare the disinfecting efficacy of the sodium hypochlorite irrigation by root can... more Objective: To compare the disinfecting efficacy of the sodium hypochlorite irrigation by root canal preparation with stainless steel hand files, taper 0.02 and nickel-titanium Mtwo files with taper 0.04-0.06. Study Design: 40 extracted human teeth were sterilized, and then inoculated with Enterococcus faecalis (ATCC 29212). After 6 day incubation time the root canals were prepared by hand with K-files (n=20) and by engine-driven Mtwo files (VDW, Munich, Germany) (n=20). Irrigation was carried out with 2.5 % NaOCl in both cases. Samples were taken and determined in colony forming units (CFU) from the root canals before and after the preparation with instruments #25 and #35. Results: Significant reduction in bacterial count was determined after filing at both groups. The number of bacteria kept on decreasing with the extension of apical preparation diameter. There was no significant difference between the preparation sizes in the bacterial counts after hand or engine-driven instrument...
Fogorvosi szemle, 2005
The aim of the authors' study was to compare the remaining root canal wall thickness and the ... more The aim of the authors' study was to compare the remaining root canal wall thickness and the preparation time of root canals, prepared either with step-back technique, or with GT Rotary File, an engine driven nickel-titanium rotary instrument system. Twenty extracted molars were decoronated. Teeth were divided in two groups. In Group 1 root canals were prepared with step-back technique. In Group 2 GT Rotary File System was utilized. Preoperative vestibulo-oral X-ray pictures were taken from all teeth with radiovisiograph (RVG). The final preparations at the mesiobuccal canals (MB) were performed with size #30 and palatinal/distal canals with size #40 instruments. Postoperative RVG pictures were taken ensuring the preoperative positioning. The working time was measured in seconds during each preparation. The authors also assessed the remaining root canal wall thickness at 3, 6 and 9 mm from the radiological apex, comparing the width of the canal walls of the vestibulo-oral projec...
The purpose of this study was to compare the accuracy of electronic and radiographical working le... more The purpose of this study was to compare the accuracy of electronic and radiographical working length determination in extracted molars. Palatal root canals of twenty maxillary molars were used. Teeth were randomly divided into two groups. In case of the first group the working length was measured by apex locator (Propex, Dentsply-Maillefer), and in the second group it was measured with radiographic method (RVG, Trophy). The files, used for measuring the working length, were cemented into the teeth. The apical half of the root was ground, and the tips of the files visualised as well as the apical region of the root canal with the apical constriction. Standard digital photographs were taken from the prepared samples, and the distance between the tip of the file and the physiological foramen was measured. Two sample t test was used for statistical analysis. The physiological foramen was approached on average to 0.11 mm by the electronic method and to 0.58 mm by the radiological method...
Digitales Lernmaterial fur Zahnmedizin Studenten. Hilft bei der Synthese der theoretiscen und kli... more Digitales Lernmaterial fur Zahnmedizin Studenten. Hilft bei der Synthese der theoretiscen und klinischen Wissenschaften.
Dentistry
Introduction: The microsonic technique is widely used for separated endodontic instrument removal... more Introduction: The microsonic technique is widely used for separated endodontic instrument removal. Aim: We evaluated the usability of the Miller broach with the microsonic technique during separated instrument retrieval. Case report: An attempt was made to remove a fractured instrument using a modified Miller needle mounted in a piezoelectric scaler under the visualization of an operating microscope. The conditions of the procedure were noted. The removal was successful. Severe preparation error did not revealed. Discussion: The Miller needle have the properties for use in a modified microsonic technique. It can be bent to the individual situation and the preparation is considerable on the tip of the instrument. The procedure can be wellcontrolled and the operator may avoid excessive dentin removal. Conclusion and clinical relevance: The Miller broach fulfills the requirements of the microsonic technique and have financial advantages.
Quintessence international, 2018
OBJECTIVE The goal was to investigate the clinical value of two-dimensional radiographs and diffe... more OBJECTIVE The goal was to investigate the clinical value of two-dimensional radiographs and different radiographic measurement techniques before instrument removal with a microsonic technique. The aim was to find an easy-to-use technique for predicting the success of removal and case evaluation. Additionally the quality of root canal filling after instrument removal was assessed. METHOD AND MATERIALS This retrospective study analyzed patients' records and preoperative and postoperative periapical radiographs made using the paralleling technique. On preoperative radiographs, canal access angle and Schneider and Weine angle of root canal curvature were measured and compared. The Schäfer method was used for measuring the radius of curvature. In cases of successful removal taper, homogeneity and length of obturation were evaluated on postoperative radiographs. RESULTS A total of 123 cases of instrument removal were investigated. In total, 97 fragments (78.9%) were removed successful...
The purpose of this retrospective study was to evaluate and describe the occurrence of different ... more The purpose of this retrospective study was to evaluate and describe the occurrence of different deficiencies of composite restorations in molar and premolar teeth. Further aim was to investigate possible correlations between occurring malformations and the localization or size of the restorations. 240 class II composite restorations (in 85 patients) were involved in the study. Control examinations were carried out five years after restorations, according to the United States Public Health Services' criteria. Namely, anatomic form, marginal integrity, marginal stain, color stability, surface smoothness, and the presence of secondary caries or fractures of the restorations. The associations between variables were calculated by bivariate analyses using either Pearson chi-square or Fisher tests. P < 0.05 was considered significant. In 0.8% of the fillings, secondary caries and in 0.4% of the cases, fracture was found as a failure. The frequency of adjacent deficiencies were foun...
Australian Endodontic Journal
The present report describes a case where sealer extrusion (Sealapex) occurred during root canal ... more The present report describes a case where sealer extrusion (Sealapex) occurred during root canal obturation of a left lower second premolar tooth, and the patient experienced sudden pain and followed by complete anaesthesia of the lower lip. After 3 weeks of conservative therapy and an unaltered anaesthesia period, piezosurgical removal of the extruded sealer and root-end resection was performed despite the direct contact with the mental neurovascular bundle. At suture removal, 1 week after surgery, there was no improvement in sensation. Two weeks after the operation, the patient reported some changes, including a short paraesthesia period alternating with anaesthesia. At the fourth post-operative week, neurosensory function recovered completely. This case represents successful use of the piezoelectric technique for mental nerve decompression and periapical surgery of a lower second premolar with close contact of the mental nerve.
Journal of clinical and experimental dentistry, 2016
The purpose of this study was to investigate the consistency of working length control between ha... more The purpose of this study was to investigate the consistency of working length control between hand instrumentation in comparison to engine driven Mtwo nickel-titanium rotary files. Forty extracted maxillary molars were selected and divided onto two parallel groups. The working lengths of the mesiobuccal root canals were estimated. The teeth were fixed in a phantom head. The root canal preparation was carried out group 1 (n=20) with hand K-files, (VDW, Munich, Germany) and group 2 (n=20) with Mtwo instruments (VDW, Munich, Germany). Vestibulo-oral and mesio-distal directional x-ray images were taken before the preparation with #10 K-file, inserted into the mesiobuccal root canal to the working length, and after preparation with #25, #30 and #40 files. Working lenght changes were detected with measurements between the radiological apex and the instrument tips. In the Mtwo group a difference in the working competency (p<0.05) could be noticed only in the vestibulo-oral direction fr...
Fogorvosi szemle
The aim of the authors' study was to compare the remaining root canal wall thickness and the ... more The aim of the authors' study was to compare the remaining root canal wall thickness and the preparation time of root canals, prepared either with step-back technique, or with GT Rotary File, an engine driven nickel-titanium rotary instrument system. Twenty extracted molars were decoronated. Teeth were divided in two groups. In Group 1 root canals were prepared with step-back technique. In Group 2 GT Rotary File System was utilized. Preoperative vestibulo-oral X-ray pictures were taken from all teeth with radiovisiograph (RVG). The final preparations at the mesiobuccal canals (MB) were performed with size #30 and palatinal/distal canals with size #40 instruments. Postoperative RVG pictures were taken ensuring the preoperative positioning. The working time was measured in seconds during each preparation. The authors also assessed the remaining root canal wall thickness at 3, 6 and 9 mm from the radiological apex, comparing the width of the canal walls of the vestibulo-oral projec...
Fogorvosi szemle, 2008
The purpose of this study was to compare the accuracy of electronic and radiographical working le... more The purpose of this study was to compare the accuracy of electronic and radiographical working length determination in extracted molars. Palatal root canals of twenty maxillary molars were used. Teeth were randomly divided into two groups. In case of the first group the working length was measured by apex locator (Propex, Dentsply-Maillefer), and in the second group it was measured with radiographic method (RVG, Trophy). The files, used for measuring the working length, were cemented into the teeth. The apical half of the root was ground, and the tips of the files visualised as well as the apical region of the root canal with the apical constriction. Standard digital photographs were taken from the prepared samples, and the distance between the tip of the file and the physiological foramen was measured. Two sample t test was used for statistical analysis. The physiological foramen was approached on average to 0.11 mm by the electronic method and to 0.58 mm by the radiological method...
Digital learning material. It gives a guideline to dental studies and helps them to syntetisez fr... more Digital learning material. It gives a guideline to dental studies and helps them to syntetisez from theoretic to clinical studies.
Quintessence: Publicación internacional de odontología, 2018
Objetivo: el objetivo fue investigar el valor clinico de las radiografias bidimensionales y de la... more Objetivo: el objetivo fue investigar el valor clinico de las radiografias bidimensionales y de las diferentes tecnicas de medicion radiologica a la hora de recuperar los instrumentos con una tecnica microsonica. Se trataba, asimismo, de hallar una tecnica sencilla de implementar que predijera el exito de la remocion y facilitara la valoracion del caso. De modo adicional, se valoro la calidad de la obturacion de los conductos tras la recuperacion del instrumental. Metodo y materiales: este estudio retrospectivo analizo las historias clinicas y las radiografias periapicales pre- y posoperatorias de los pacientes, las cuales se habian realizado con la tecnica del paralelismo. Sobre las radiografias preoperatorias, se midieron y compararon el angulo de acceso al canal y los angulos Schneider y Weine de la curvatura del canal. Para medir el radio de la curvatura, se utilizo el metodo Schafer. Se utilizaron las radiografias posoperatorias para valorar la conicidad, la homogeneidad y la longitud de la obturacion de los casos que tuvieron exito en la recuperacion del instrumento separado. Resultados: se investigaron 123 casos de instrumental separado. En total, se recuperaron 97 fragmentos (78,9%) con exito. Se llevo a cabo un analisis estadistico con el chi cuadrado de Pearson y el test Fisher exact (α< 0,05). La localizacion del fragmento en relacion a la curvatura del canal, el angulo de acceso y el angulo de Schneider influyeron de manera significativa en el exito. Se relaciono la mayor probabilidad de recuperacion con un angulo de acceso al canal radicular > 20 grados y un angulo de Schneider > 40 grados. Solo el 26,3% de las obturaciones cumplieron todos los estandares tecnicos establecidos. Una alterada conocidad pudo identificarse en el 64,2% de los casos y se asocio siempre a la formacion de escalones. Conclusion: la remocion microsonica trata de un metodo eficaz para recuperar los instrumentos separados. El uso de una sola tecnica de medicion radiologica sobre una radiografia periapical no resulta suficiente para valorar con precision la anatomia del canal radicular, la dificultad del caso y la probabilidad de una recuperacion exitosa. Las obturaciones posoperatorias son, en su mayor parte, de deficiente calidad.
Quintessence International, 2018
Objective: The goal was to investigate the clinical value of two-dimensional radiographs and diff... more Objective: The goal was to investigate the clinical value of two-dimensional radiographs and different radiographic measurement techniques before instrument removal with a microsonic technique. The aim was to find an easy-to-use technique for predicting the success of removal and case evaluation. Additionally the quality of root canal filling after instrument removal was assessed. Method and Materials: This retrospective study analyzed patients' records and preoperative and postoperative periapical radiographs made using the paralleling technique. On preoperative radiographs, canal access angle and Schneider and Weine angle of root canal curvature were measured and compared. The Schäfer method was used for measuring the radius of curvature. In cases of successful removal taper, homogeneity and length of obturation were evaluated on postoperative radiographs. Results: A total of 123 cases of instrument removal were investigated. In total, 97 fragments (78.9%) were removed successfully. Statistical analysis was performed with Pearson's chi-square and Fisher's exact test (α < .05). The site of fragment relative to canal curvature, canal access angle, and Schneider angle significantly influenced the success of removal. The highest chance of removal failure was associated with > 20 degrees of canal access angle and > 40 degrees of Schneider angle. Only 26.3% of obturations met all technical standards. Altered taper could be identified in 64.2% and was always associated with ledge formation. Conclusion: Microsonic removal is a successful method to retrieve separated instruments. The use of only one radiographic measurement technique is not sufficient to precisely evaluate root canal anatomy, case difficulty, and chance of successful removal before instrument removal on a periapical radiograph. Postoperative root canal fillings are mainly substandard.
Pécsi Tudományegyetem, Jun 4, 2020
Australian Endodontic Journal, Oct 18, 2018
The present report describes a case where sealer extrusion (Sealapex) occurred during root canal ... more The present report describes a case where sealer extrusion (Sealapex) occurred during root canal obturation of a left lower second premolar tooth, and the patient experienced sudden pain and followed by complete anaesthesia of the lower lip. After 3 weeks of conservative therapy and an unaltered anaesthesia period, piezosurgical removal of the extruded sealer and root-end resection was performed despite the direct contact with the mental neurovascular bundle. At suture removal, 1 week after surgery, there was no improvement in sensation. Two weeks after the operation, the patient reported some changes, including a short paraesthesia period alternating with anaesthesia. At the fourth post-operative week, neurosensory function recovered completely. This case represents successful use of the piezoelectric technique for mental nerve decompression and periapical surgery of a lower second premolar with close contact of the mental nerve.
Applied Sciences
Endodontic preparation with ultrasonic instruments can lead to temperature rise (TR) on the exter... more Endodontic preparation with ultrasonic instruments can lead to temperature rise (TR) on the external root surface (ERF), which may damage the periodontium. The aim was to measure the TR due to the ultrasonic preparation applied at different energy levels and durations during the removal of broken endodontic instrument from the root canal. Thirty-five maxillary central incisors were decoronated and 4 mm of NiTi instruments were fractured 5 mm from the most coronal part of the root. The roots were divided into seven groups according to the preparation mode (endodontic-E5, periodontal-P3) and preparation duration (30 s, 45 s, 60 s). Ultrasonic preparation was performed in periods consisting of four preparation phases with intermediate irrigations and drying. During all preparations, the TR was recorded on ERF using a K-type thermocouple. The results demonstrated that the TR measured at the end of the preparation period was higher than at baseline in all groups (p < 0.001). The large...
Dental materials : official publication of the Academy of Dental Materials, 2015
This 10-year retrospective study investigated the differences in the changes and the longevity of... more This 10-year retrospective study investigated the differences in the changes and the longevity of Class II restorations using 4 similar microhybrid resin composites (Filtek Z250, Herculite XR, Gradia Direct Posterior, Renew). Data were collected from patient records. Those patients who received posterior restoration between 2001 and 2003, and who still visited the clinical practice for regular check-up visits were selected. A total of 225 adult patients (86 males, 139 females) with 701 restorations were evaluated by 2 operators using the USPHS criteria. Data were analyzed with Fisher's Exact Test, Pearson's Chi-Square Test and Kaplan-Meier analysis (p<0.05). A failure rate of 2.1% was detected. The reasons of failures included restoration fracture, secondary caries and endodontic treatment. Similar survival rates for Gradia Direct Posterior (91.25%) and Renew (92.19%) were observed; better performance was observed with the Filtek Z250 (99.1%) and Herculite XR (98.64%). Th...
Objetivo: el objetivo fue investigar el valor clinico de las radiografias bidimensionales y de la... more Objetivo: el objetivo fue investigar el valor clinico de las radiografias bidimensionales y de las diferentes tecnicas de medicion radiologica a la hora de recuperar los instrumentos con una tecnica microsonica. Se trataba, asimismo, de hallar una tecnica sencilla de implementar que predijera el exito de la remocion y facilitara la valoracion del caso. De modo adicional, se valoro la calidad de la obturacion de los conductos tras la recuperacion del instrumental. Metodo y materiales: este estudio retrospectivo analizo las historias clinicas y las radiografias periapicales pre- y posoperatorias de los pacientes, las cuales se habian realizado con la tecnica del paralelismo. Sobre las radiografias preoperatorias, se midieron y compararon el angulo de acceso al canal y los angulos Schneider y Weine de la curvatura del canal. Para medir el radio de la curvatura, se utilizo el metodo Schafer. Se utilizaron las radiografias posoperatorias para valorar la conicidad, la homogeneidad y la lo...
Objective: To compare the disinfecting efficacy of the sodium hypochlorite irrigation by root can... more Objective: To compare the disinfecting efficacy of the sodium hypochlorite irrigation by root canal preparation with stainless steel hand files, taper 0.02 and nickel-titanium Mtwo files with taper 0.04-0.06. Study Design: 40 extracted human teeth were sterilized, and then inoculated with Enterococcus faecalis (ATCC 29212). After 6 day incubation time the root canals were prepared by hand with K-files (n=20) and by engine-driven Mtwo files (VDW, Munich, Germany) (n=20). Irrigation was carried out with 2.5 % NaOCl in both cases. Samples were taken and determined in colony forming units (CFU) from the root canals before and after the preparation with instruments #25 and #35. Results: Significant reduction in bacterial count was determined after filing at both groups. The number of bacteria kept on decreasing with the extension of apical preparation diameter. There was no significant difference between the preparation sizes in the bacterial counts after hand or engine-driven instrument...
Fogorvosi szemle, 2005
The aim of the authors' study was to compare the remaining root canal wall thickness and the ... more The aim of the authors' study was to compare the remaining root canal wall thickness and the preparation time of root canals, prepared either with step-back technique, or with GT Rotary File, an engine driven nickel-titanium rotary instrument system. Twenty extracted molars were decoronated. Teeth were divided in two groups. In Group 1 root canals were prepared with step-back technique. In Group 2 GT Rotary File System was utilized. Preoperative vestibulo-oral X-ray pictures were taken from all teeth with radiovisiograph (RVG). The final preparations at the mesiobuccal canals (MB) were performed with size #30 and palatinal/distal canals with size #40 instruments. Postoperative RVG pictures were taken ensuring the preoperative positioning. The working time was measured in seconds during each preparation. The authors also assessed the remaining root canal wall thickness at 3, 6 and 9 mm from the radiological apex, comparing the width of the canal walls of the vestibulo-oral projec...
The purpose of this study was to compare the accuracy of electronic and radiographical working le... more The purpose of this study was to compare the accuracy of electronic and radiographical working length determination in extracted molars. Palatal root canals of twenty maxillary molars were used. Teeth were randomly divided into two groups. In case of the first group the working length was measured by apex locator (Propex, Dentsply-Maillefer), and in the second group it was measured with radiographic method (RVG, Trophy). The files, used for measuring the working length, were cemented into the teeth. The apical half of the root was ground, and the tips of the files visualised as well as the apical region of the root canal with the apical constriction. Standard digital photographs were taken from the prepared samples, and the distance between the tip of the file and the physiological foramen was measured. Two sample t test was used for statistical analysis. The physiological foramen was approached on average to 0.11 mm by the electronic method and to 0.58 mm by the radiological method...
Digitales Lernmaterial fur Zahnmedizin Studenten. Hilft bei der Synthese der theoretiscen und kli... more Digitales Lernmaterial fur Zahnmedizin Studenten. Hilft bei der Synthese der theoretiscen und klinischen Wissenschaften.
Dentistry
Introduction: The microsonic technique is widely used for separated endodontic instrument removal... more Introduction: The microsonic technique is widely used for separated endodontic instrument removal. Aim: We evaluated the usability of the Miller broach with the microsonic technique during separated instrument retrieval. Case report: An attempt was made to remove a fractured instrument using a modified Miller needle mounted in a piezoelectric scaler under the visualization of an operating microscope. The conditions of the procedure were noted. The removal was successful. Severe preparation error did not revealed. Discussion: The Miller needle have the properties for use in a modified microsonic technique. It can be bent to the individual situation and the preparation is considerable on the tip of the instrument. The procedure can be wellcontrolled and the operator may avoid excessive dentin removal. Conclusion and clinical relevance: The Miller broach fulfills the requirements of the microsonic technique and have financial advantages.
Quintessence international, 2018
OBJECTIVE The goal was to investigate the clinical value of two-dimensional radiographs and diffe... more OBJECTIVE The goal was to investigate the clinical value of two-dimensional radiographs and different radiographic measurement techniques before instrument removal with a microsonic technique. The aim was to find an easy-to-use technique for predicting the success of removal and case evaluation. Additionally the quality of root canal filling after instrument removal was assessed. METHOD AND MATERIALS This retrospective study analyzed patients' records and preoperative and postoperative periapical radiographs made using the paralleling technique. On preoperative radiographs, canal access angle and Schneider and Weine angle of root canal curvature were measured and compared. The Schäfer method was used for measuring the radius of curvature. In cases of successful removal taper, homogeneity and length of obturation were evaluated on postoperative radiographs. RESULTS A total of 123 cases of instrument removal were investigated. In total, 97 fragments (78.9%) were removed successful...
The purpose of this retrospective study was to evaluate and describe the occurrence of different ... more The purpose of this retrospective study was to evaluate and describe the occurrence of different deficiencies of composite restorations in molar and premolar teeth. Further aim was to investigate possible correlations between occurring malformations and the localization or size of the restorations. 240 class II composite restorations (in 85 patients) were involved in the study. Control examinations were carried out five years after restorations, according to the United States Public Health Services' criteria. Namely, anatomic form, marginal integrity, marginal stain, color stability, surface smoothness, and the presence of secondary caries or fractures of the restorations. The associations between variables were calculated by bivariate analyses using either Pearson chi-square or Fisher tests. P < 0.05 was considered significant. In 0.8% of the fillings, secondary caries and in 0.4% of the cases, fracture was found as a failure. The frequency of adjacent deficiencies were foun...
Australian Endodontic Journal
The present report describes a case where sealer extrusion (Sealapex) occurred during root canal ... more The present report describes a case where sealer extrusion (Sealapex) occurred during root canal obturation of a left lower second premolar tooth, and the patient experienced sudden pain and followed by complete anaesthesia of the lower lip. After 3 weeks of conservative therapy and an unaltered anaesthesia period, piezosurgical removal of the extruded sealer and root-end resection was performed despite the direct contact with the mental neurovascular bundle. At suture removal, 1 week after surgery, there was no improvement in sensation. Two weeks after the operation, the patient reported some changes, including a short paraesthesia period alternating with anaesthesia. At the fourth post-operative week, neurosensory function recovered completely. This case represents successful use of the piezoelectric technique for mental nerve decompression and periapical surgery of a lower second premolar with close contact of the mental nerve.
Journal of clinical and experimental dentistry, 2016
The purpose of this study was to investigate the consistency of working length control between ha... more The purpose of this study was to investigate the consistency of working length control between hand instrumentation in comparison to engine driven Mtwo nickel-titanium rotary files. Forty extracted maxillary molars were selected and divided onto two parallel groups. The working lengths of the mesiobuccal root canals were estimated. The teeth were fixed in a phantom head. The root canal preparation was carried out group 1 (n=20) with hand K-files, (VDW, Munich, Germany) and group 2 (n=20) with Mtwo instruments (VDW, Munich, Germany). Vestibulo-oral and mesio-distal directional x-ray images were taken before the preparation with #10 K-file, inserted into the mesiobuccal root canal to the working length, and after preparation with #25, #30 and #40 files. Working lenght changes were detected with measurements between the radiological apex and the instrument tips. In the Mtwo group a difference in the working competency (p<0.05) could be noticed only in the vestibulo-oral direction fr...
Fogorvosi szemle
The aim of the authors' study was to compare the remaining root canal wall thickness and the ... more The aim of the authors' study was to compare the remaining root canal wall thickness and the preparation time of root canals, prepared either with step-back technique, or with GT Rotary File, an engine driven nickel-titanium rotary instrument system. Twenty extracted molars were decoronated. Teeth were divided in two groups. In Group 1 root canals were prepared with step-back technique. In Group 2 GT Rotary File System was utilized. Preoperative vestibulo-oral X-ray pictures were taken from all teeth with radiovisiograph (RVG). The final preparations at the mesiobuccal canals (MB) were performed with size #30 and palatinal/distal canals with size #40 instruments. Postoperative RVG pictures were taken ensuring the preoperative positioning. The working time was measured in seconds during each preparation. The authors also assessed the remaining root canal wall thickness at 3, 6 and 9 mm from the radiological apex, comparing the width of the canal walls of the vestibulo-oral projec...
Fogorvosi szemle, 2008
The purpose of this study was to compare the accuracy of electronic and radiographical working le... more The purpose of this study was to compare the accuracy of electronic and radiographical working length determination in extracted molars. Palatal root canals of twenty maxillary molars were used. Teeth were randomly divided into two groups. In case of the first group the working length was measured by apex locator (Propex, Dentsply-Maillefer), and in the second group it was measured with radiographic method (RVG, Trophy). The files, used for measuring the working length, were cemented into the teeth. The apical half of the root was ground, and the tips of the files visualised as well as the apical region of the root canal with the apical constriction. Standard digital photographs were taken from the prepared samples, and the distance between the tip of the file and the physiological foramen was measured. Two sample t test was used for statistical analysis. The physiological foramen was approached on average to 0.11 mm by the electronic method and to 0.58 mm by the radiological method...