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1.
J Endod ; 46(1): 110-115, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31740067

RESUMEN

INTRODUCTION: The aim of this study was to compare a reduction in working length and area of canal enlargement resulting from instrumentation with Hedström (Kerr Dental, Orange, CA), K (Kerr Dental), ProTaper Next (Dentsply Sirona, York, PA), and TF Adaptive (Kerr Dental) files. The effect of the canal curvature on the working length and area of canal enlargement was also assessed. METHODS: A total of 80 plastic canal models were used, 40 with a canal curvature of 10° and another 40 with a canal curvature of 30°. Instrumentation of 10 models with a 10° canal curvature and 10 models with a 30° canal curvature was performed using each of the file systems up to size 25. Working length measurements were taken before and after instrumentation with each file type and size. Twenty composite images were made from superimposition of pre- and postpreparation photographs, and the difference in area was calculated using ImageJ software (National Institutes of Health, Bethesda, MD). RESULTS: ProTaper Next rotary files and TF Adaptive files produced the smallest reduction in the working length and the least canal enlargement followed by Hedström files and K files, respectively. The degree of canal curvature increased the working length reduction by a significant amount when K files and ProTaper Next rotary files were used, and the degree of curvature increased canal enlargement by a significant amount when K files were used. CONCLUSIONS: Nickel-titanium rotary files produced more favorable results than stainless steel hand files in terms of maintaining a consistent working length and producing minimal canal enlargement. Hedström files performed significantly better than K files in terms of working length reduction and canal enlargement.


Asunto(s)
Cavidad Pulpar , Preparación del Conducto Radicular , Aleaciones Dentales , Instrumentos Dentales , Diseño de Equipo , Preparación del Conducto Radicular/instrumentación , Titanio
2.
Gen Dent ; 68(1): 36-39, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31859660

RESUMEN

The aim of this study was to compare, in pairs, the cyclic fatigue resistance, scanning electron microscopic (SEM) appearance, and energy-dispersive X-ray (EDX) profiles of 6 rotary files: ProTaper Gold vs EdgeTaper Platinum; ProTaper Universal vs EdgeTaper; and Vortex Blue vs EdgeSequel Sapphire. Six types of rotary file were tested in 2 sizes of each type. A 3-point cyclic fatigue apparatus imparting a 60-degree angle of curvature and a 3-mm radius of curvature was used to evaluate 30 files of each type and size. The cyclic fatigue testing results from similar file types and sizes were paired for statistical analysis. After fatigue testing was completed, 36 files (3 of each type and size) were randomly selected for SEM imaging and EDX analysis. When similar file types and sizes were paired in independent-samples t tests, statistically significant differences (P < 0.0001) in cyclic fatigue resistance were established. For both tested sizes, EdgeTaper Platinum exhibited significantly greater fatigue resistance than ProTaper Gold. ProTaper Universal and EdgeTaper each demonstrated significantly greater fatigue resistance than the other system in 1 size pairing. Vortex Blue exhibited significantly greater fatigue resistance than EdgeSequel Sapphire in both size pairings. In general, the heat-treated files demonstrated greater cyclic fatigue resistance than the non-heat-treated files. The SEM images verified that fracture patterns were consistent with cyclic fatigue failure. Differences in file design between the matched pairs were noted, particularly at the tips. The EDX comparisons showed that nickel and titanium were present in similar percentages (1:1 atomic ratio) for all file types. The disparities in cyclic fatigue results and tip design indicate that clinicians should not expect identical clinical performance from different files.


Asunto(s)
Instrumentos Dentales , Falla de Equipo , Microscopía Electrónica de Rastreo/métodos , Preparación del Conducto Radicular , Aleaciones Dentales , Diseño de Equipo , Humanos , Ensayo de Materiales , Níquel , Estrés Mecánico , Titanio
3.
J Endod ; 45(12): 1529-1534, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31757340

RESUMEN

INTRODUCTION: Electrically heated pluggers are the most commonly used instruments during warm obturation techniques. This study aimed to evaluate the effect of sterilization and operating temperature settings on the heat generation of pluggers of various taper sizes. METHODS: Fifty pluggers were sterilized at 132°C for 25 minutes for a total of 150 cycles. One group (Autoclave200) consisted of 25 pluggers tested at an operating temperature setting of 200°C, whereas another group (Autoclave400) consisted of 25 pluggers tested at 400°C. The heat generation at their tip surface was measured with T-type thermocouples at 0, 50, 100, and 150 autoclave cycles. An unpaired t test was used to compare the time it took the pluggers to reach 60°C and the mean maximum temperature change. RESULTS: After 50 autoclave cycles, all of the 0.04 taper pluggers in Autoclave200 failed to reach 60°C. After 100 autoclave cycles, one of the 0.10 taper pluggers in Autoclave200 did not reach 60°C, and after 150 autoclave cycles, one of the 0.04 taper pluggers failed to generate any heat. The mean increase in the time to reach 60°C ranged from 1071-4004 milliseconds and 510-2074 milliseconds for Autoclave200 and Autoclave400, respectively. The mean maximum temperature change decreased by 13-29°C and 24-116°C for Autoclave200 and Autoclave400, respectively. CONCLUSIONS: After multiple autoclave cycles and higher operating temperature use, the electrically heated pluggers transferred less heat to the tip surface, potentially making them less effective.


Asunto(s)
Instrumentos Dentales , Calor , Obturación del Conducto Radicular , Esterilización , Temperatura Ambiental , Termómetros
4.
Am J Dent ; 32(5): 251-254, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31675194

RESUMEN

PURPOSE: To evaluate the accuracy of mechanical torque rachet types based on the number of uses. METHODS: A total of 25 ratchets, including three frictional- and two spring-type torque ratchets from every mechanical torque ratchet group, were used in our study. A digital torque measurement device was used in assessing the efficiency of mechanical torque ratchets. All ratchets were tightened according to the torque values recommended by the companies. The ratchets were tightened 500 times in total. RESULTS: Given the changes in torque delivery by the number of uses, a statistically significant torque loss was observed in the Bego ratchets (P< 0.05), and a statistically significant increase was found in the torque values of the other ratchet groups (P< 0.05). The highest increase in torque values was obtained in the MEDENTIKA ratchet group. CLINICAL SIGNIFICANCE: This study showed that there are changes in the torque values applied based on the number of rachet uses. Thus, clinicians are advised to regularly evaluate the accuracy of the rachets.


Asunto(s)
Instrumentos Dentales , Torque
5.
Gen Dent ; 67(6): 34-37, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31658022

RESUMEN

Although the incidence of broken needles in dental practice is minimal, needle breakage can occur as a result of manufacturing defects, inadequate patient management, or poor practitioner technique. Retrieval of a broken needle is justified not only because of the potential for needle migration but also because of psychological and medicolegal considerations. This case report describes the surgical removal of a dental needle that fractured during an attempt at local anesthesia. Identifying the precise location of the broken needle fragment and its relationship with the surrounding bones, vessels, and nerves is essential to designing an adequate treatment plan. If surgical retrieval is indicated, it should be performed immediately, especially in cases in which the needle fragment has not been bent or deformed. In the present case, the use of C-arm fluoroscopy aided the surgical removal while saving time and reducing the cost of treatment.


Asunto(s)
Anestesia Dental , Falla de Equipo , Cuerpos Extraños , Agujas , Anestesia Local , Instrumentos Dentales , Humanos
6.
Braz Oral Res ; 33: e097, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31664360

RESUMEN

To evaluate the torsional properties of engine-driven pathfinding instruments manufactured from different NiTi alloys - R-Pilot (tip size 12.5;.04 taper; M-Wire) and One G (tip size 14;.03 taper; Conventional NiTi). A total of 40 NiTi instruments from engine-driven pathfinding instruments (n = 20) were used. The torsion tests followed ISO 3630-1 (1992). Three millimeters of each instrument tip was fastened to a small load cell by a lever arm linked to the axis of torsion. During the test, the torsion testing machine software measured the maximum torsional strength and angle of rotation (0) before instrument failure. The fractured surface of each instrument was assessed by scanning electron microscopy (SEM). In addition, a supplementary examination was performed to measure the cross-sectional area and the metal mass volume of each instrument 3 mm from the tip. Data were analyzed using a t-test, with significance level set at 5%. R-pilot had significantly higher torsional strength than did One G (p < 0.05). Regarding the angle of rotation to fracture, One G had higher angles than did R-Pilot (p < 0.05). The supplementary examination showed that R-Pilot had the highest cross-sectional area and volume of metal mass at 3 mm from the tip (p < 0.05). R-pilot (M-Wire NiTi alloy) had a significantly higher torsional strength and One-G (superelastic NiTi alloy) had the highest angle of rotation to fracture.


Asunto(s)
Aleaciones/química , Aleaciones Dentales/química , Instrumentos Dentales , Preparación del Conducto Radicular/instrumentación , Análisis de Varianza , Diseño de Equipo , Análisis de Falla de Equipo , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Valores de Referencia , Reproducibilidad de los Resultados , Estadísticas no Paramétricas , Estrés Mecánico , Propiedades de Superficie , Torque
7.
Niger J Clin Pract ; 22(10): 1335-1340, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31607721

RESUMEN

Objective: The purpose of this study was to evaluate the cyclic fatigue resistances of the WaveOne Gold (WOG), ProTaper Next (PTN), 2Shape (TS) instruments. Materials and Methods: Totally 45 new WOG (25/.07), PTN (25/.06), TS (25/.06) files were tested inside the artificial canal of a custom-made stainless steel block with an inner diameter of 1.5 mm, a 60° angle, and a 5-mm radius of curvature. A 16-mm-long file segment (from the tip) was introduced and was immersed in 37°C water. The number of cycles to fracture (NCF), time to failure (TTF), fractured fragment length (FL) was recorded and the fractured surface was examined using microscope. Results: WOG > PTN > TS according to TTF results (P = 0.00). PTN > TS according to NCF results (P = 0.00). The FL values showed no significant difference (P = 0.335). Conclusions: Reciprocating motion can be used more safely than continuous rotation due to the higher cyclic fatigue resistance.


Asunto(s)
Aleaciones Dentales , Instrumentos Dentales , Preparación del Conducto Radicular/instrumentación , Temperatura Ambiental , Aleaciones , Análisis del Estrés Dental , Falla de Equipo , Oro , Humanos , Níquel , Rotación , Acero Inoxidable , Titanio
8.
Compend Contin Educ Dent ; 40(9): e8-e13, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31573215

RESUMEN

Iatrogenic perforation is a procedural incident that may occur in endodontic treatments of primary and/or permanent teeth. Prognosis may be favorable if a complete seal with biomaterial is immediately established. Several materials, including glass-ionomer cement (GIC), have been used to seal different types of perforation defects. GIC is considered to be biocompatible, nontoxic, and non-irritating, and promotes bone healing and cementum regeneration. In the present case, GIC was used to treat an endodontic perforation. The perforation was cleaned with periodontal curettes and sealed with GIC. A reintervention was needed in which sealing was performed with a light-curing GIC, a material that was less rough than the initial material used. After 2 years, the absence of periradicular radiolucent lesions, pain, and swelling along with functional tooth stability indicated a successful outcome of sealing perforation in the case.


Asunto(s)
Dentición Permanente , Cementos de Ionómero Vitreo , Instrumentos Dentales
9.
J Endod ; 45(11): 1365-1370, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31564462

RESUMEN

INTRODUCTION: This study aimed to analyze the effects of ultrasonic removal of fractured files from the middle third of root canals on the vertical root fracture resistance. METHODS: This study was an extension of a previous study assessing the effects of fractured file removal on dentinal microcracks. It included 18 bilaterally matched pairs of human mandibular incisors prepared and analyzed in the previous study. Briefly, 1 member of each pair was assigned to an ultrasonic or a control group. In the ultrasonic group, K-files were fractured in the middle third of canals followed by ultrasonic file removal and canal preparation. In the control group, the root canals were simply prepared. Micro-computed tomographic imaging was performed before and after treatment, and the cross-sectional root images were screened for microcracks. For the present study, 3-dimensional reconstruction was performed for volumetric assessments. The fracture resistance was measured using a universal testing machine. All data were statistically analyzed. RESULTS: Fracture loads were significantly smaller in the ultrasonic group (P < .05). The percentage increase in the canal volume significantly influenced the root fracture resistance (P < .05), whereas microcracks had no significant effect (P > .05). CONCLUSIONS: Ultrasonic removal of fractured instruments from the middle third of root canals lowers the vertical root fracture resistance, with increased dentin removal being the primary cause.


Asunto(s)
Instrumentos Dentales , Cavidad Pulpar , Falla de Equipo , Preparación del Conducto Radicular , Ultrasonido , Estudios Transversales , Dentina , Humanos
10.
Braz Oral Res ; 33: e021, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31508722

RESUMEN

This study investigated the effectiveness of XP-Endo Finisher (XPF) associated with XP-Endo Shaper (XPS) or Reciproc Blue (RB) files in reducing bacterial load in oval-shaped root canals (RC) during chemomechanical preparation (CMP) using 0.9% saline solution (NaCl) or 2.5% sodium hypochlorite (NaOCl). Eighty mandibular incisors with single oval-shaped RC were contaminated with Enterococcus faecalis. The teeth were randomly assigned to eight experimental groups (n = 10) according to the CMP, as follows: G1: XPS, G2: XPS + XPF, G3: RB, and G4: RB + XPF. CMP was performed with NaCl or NaOCl. The reduction of bacterial load was assessed by colony-forming unit count before (S1) and after (S2) CMP. Data normality was verified by using Shapiro-Wilk test. ANOVA, Tukey's test, and Bonferroni post-hoc test were used at a 5% significance level. Culturable bacteria were present in all S1 samples (p>0.05). All instrumentation techniques were effective in reducing bacterial load, irrespective of the irrigating solution (p < 0.05). With the use of NaCl, RB was more effective than XPS (p = 0.035). With the use of NaOCl, XPS and RB presented similar effectiveness (p = 0.779). XPF enhanced the bacterial reduction of both systems tested (p < 0.05). The use of NaOCl improved the CMP, irrespective of the instrumentation technique used (p < 0.05). In conclusion, XPS and RB files are effective in reducing bacterial levels in oval-shaped RC. The use of XPF as a method of agitation of the irrigating solution improved the cleaning efficiency of both file systems tested. Mechanical preparation performed with saline solution decreased culturable bacteria from the root canal, but antimicrobial substances such as NaOCl should be used to achieve a significantly better disinfection.


Asunto(s)
Carga Bacteriana , Instrumentos Dentales , Cavidad Pulpar/anatomía & histología , Preparación del Conducto Radicular/instrumentación , Cavidad Pulpar/microbiología , Desinfectantes/uso terapéutico , Enterococcus faecalis/aislamiento & purificación , Infecciones por Bacterias Grampositivas , Humanos , Incisivo , Ensayo de Materiales , Solución Salina/uso terapéutico , Hipoclorito de Sodio/uso terapéutico
11.
Braz Oral Res ; 33: e039, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31508729

RESUMEN

This clinical study compared the effectiveness of two rotary systems: HyFlex CM (Coltene-Whaledent, Altstetten, Switzerland) and ProTaper Next (Dentsply Sirona, Ballaigues, Switzerland) on the removal of cultivable bacteria and endotoxins from primarily infected root canals. This study was designed as a randomized single-blinded, 2-arm, clinical trial. Twenty-four primarily infected root canals were selected and randomly divided into 2 groups: HyFlex CM (n = 12); and ProTaper Next (n = 12). Samples were collected before and after the biomechanical preparation and inoculated in specific flasks. Irrigation was performed using 2.5% sodium hypochlorite. A kinetic turbidimetric lysate assay of limulus amoebocytes was used to quantify endotoxins. Microbiological culture technique was used to determine the count of bacterial colony forming units (CFU/mL). Data collected were statistically analyzed using SigmaPlot 12.0 for Windows. The Two-Way ANOVA statistical test was performed and the level of significance was 5%. In the samples before the biomechanical preparation, cultivable bacteria and endotoxins were evidenced in 100% of the cases. The culture analysis revealed that there was no statistically significant difference in the bacterial reduction between the two instrumentation systems. Endotoxins were present in 100% of the canals after instrumentation and there was no statistical difference between the two systems in endotoxin reduction. Thus, it was concluded that both instrumentation systems were effective in reducing root canal bacteria and endotoxins with primary endodontic infection and that there was no statistical difference between them. However, no system was able to eliminate 100% of the bacteria and their by-products.


Asunto(s)
Bacterias/aislamiento & purificación , Instrumentos Dentales , Cavidad Pulpar/microbiología , Lipopolisacáridos/análisis , Preparación del Conducto Radicular/instrumentación , Adulto , Carga Bacteriana , Técnicas Bacteriológicas , Endotoxinas/análisis , Femenino , Humanos , Masculino , Ensayo de Materiales , Persona de Mediana Edad , Resultado del Tratamiento
12.
Aust Endod J ; 45(3): 400-406, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31562682

RESUMEN

The purpose of this study was to compare cyclic fatigue (CF) resistance of reciprocating instruments at body temperature and relate the findings to their martensitic transformation temperatures. Contemporary nickel-titanium (NiTi) reciprocating instruments WaveOne Primary, WaveOne Gold Primary and EdgeFile X1 (n = 20 each and #25 tip diameter) were tested for CF resistance at body temperature (37 ± 1°C). Instruments were actioned according to manufacturer guidelines until fracture occurred in a simulated canal (angle of curvature = 60°, radius of curvature = 3 mm and centre of curvature = 5 mm from the tip). Time to fracture was recorded, and data analysed using Weibull analysis. Two instruments of each were tested using differential scanning calorimetry (DSC) to assess phase transformation temperatures. Reciprocating instruments manufactured with new alloys seem to be safer to CF than those manufactured with traditional M-Wire at body temperature. Martensitic transformation temperatures seem not to relate with fatigue behaviour for reciprocating motions.


Asunto(s)
Instrumentos Dentales , Preparación del Conducto Radicular , Temperatura Corporal , Aleaciones Dentales , Diseño de Equipo , Falla de Equipo , Ensayo de Materiales , Temperatura Ambiental , Titanio
13.
Niger J Clin Pract ; 22(9): 1236-1240, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31489860

RESUMEN

Background: The aim of this study was to evaluate the effect of intracanal separated instruments with different lenghts on periapical pH levels using calcium hydroxide (CH) as an intracanal medicament. Materials and Methods: In total, 60 teeth were used. Following root canal preparation, teeth were divided into four groups (n = 15). In Group 1, 2 mm and in Group 2, 4 mm weakened from the tip of Revo-S NiTi SC2 (Micro-Mega, Besancon, France) instruments were separated in the apical portion of root canals. In Group 3, there was no separated instrument. CH paste was placed in the first three groups. In Group 4, there was no separated instrument or CH paste. Teeth were placed in containers with deionized distilled water. After 1 h and 1, 2, 7, 15, and 30 days, the pH of the solution was measured. Results: At 1 h, Group 3 showed a significantly higher pH than Groups 1 (2 mm) and 2 (4 mm; P < 0.05). At the same time point, Group 1 (2 mm) showed a higher pH than Group 2 (4 mm) without significance. At 1, 2, 7, 15, and 30 days, Group 2 (4 mm) showed a significantly lower pH than Groups 1 (2 mm) and 3 (P < 0.05). At the same time points, Group 1 (2 mm) showed a lower pH than Group 3 without significance. Conclusions: Separated instrument may affect the rise in periapical pH level when using CH as the intracanal dressing. Therefore, 4 mm of separated instrument in the apical third showed a significant effect.


Asunto(s)
Cementos para Huesos/farmacología , Hidróxido de Calcio/farmacología , Instrumentos Dentales , Materiales de Obturación del Conducto Radicular/farmacología , Diente/efectos de los fármacos , Vendajes , Humanos , Concentración de Iones de Hidrógeno , Irrigantes del Conducto Radicular/administración & dosificación , Preparación del Conducto Radicular/instrumentación , Preparación del Conducto Radicular/métodos , Irrigación Terapéutica/instrumentación , Diente/fisiología
14.
J Endod ; 45(10): 1253-1257, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31409495

RESUMEN

INTRODUCTION: The present study aimed to compare the torsional resistance of ProGlider (Dentsply Sirona, Ballaigues, Switzerland), Hyflex EDM (Coltene-Whaledent, Altstätten, Switzerland), and One G (Micro-Mega, Besancon, France) glide path instruments. METHODS: Fifteen ProGlider (16.02∼08), 15 Hyflex EDM (10.05), and 15 One G (14.03) instruments were collected and tested for torsional strength using a custom-designed testing device. Data were analyzed using 1-way analysis of variance and Tukey post hoc tests with 5% significance level. The tested specimens were examined under a scanning electron microscope. RESULTS: There was no significant difference between Hyflex EDM and ProGlider regarding their torsional resistance values (P > .05). One G showed the lowest torsional resistance (P < .05). Hyflex EDM exhibited the highest angle of rotation values among the instruments (P < .05). CONCLUSIONS: Hyflex EDM and ProGlider instruments had significantly higher torsional fatigue resistance than One G instruments, whereas Hyflex EDM showed the highest angle of rotation values. The differences in the torsional resistances might be associated with their different design features and manufacturing processes.


Asunto(s)
Instrumentos Dentales , Preparación del Conducto Radicular , Diseño de Equipo , Falla de Equipo , Ensayo de Materiales , Rotación , Torsión Mecánica
15.
J Appl Oral Sci ; 27: e20180689, 2019 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-31411264

RESUMEN

OBJECTIVE: The aim of this study was to evaluate the root canal preparation and apical enlargement of molar root canals with rotary or reciprocating heat-treated nickel-titanium (NiTi) instruments, by using micro-computed tomography (micro-CT). METHODOLOGY: Mesial root canals (n=48) of mandibular molars, with a curvature between 20° and 40°, were prepared with ProDesign Logic (PDL) 25.01 and 25.06 in rotary motion, or ProDesign R (PDR) 25.06 in reciprocating motion (PDR). Apical enlargement was performed with PDL35.01 and PDL35.05 or PDR35.05. Scanning with 9 µm resolution was performed before and after preparation, and, after apical enlargement, by using micro-CT. The percentage of volume increase, debris and untouched root canal surface, transportation, centralization and preparation time were analyzed. ANOVA and Tukey or Kruskall-Wallis and Dunn statistical tests were conducted (α=.05). RESULTS: PDL promoted a higher apical percentage of volume increase, and lower percentage of debris and untouched root canal surface than PDR 25.06 preparation in entire canal and in all thirds (P<.05). Apical enlargement with PDL 35.05 and PDR 35.05 produced a higher percentage of volume increase in the apical region in relation to the initial preparation (P<.05). PDR 35.05 and PDL 35.05 showed similar results in relation to percentage of debris and untouched root canal surface in entire canal and in all thirds (P>.05). Centralization and transportation showed no difference (P>.05). PDR required less time to perform preparation and apical enlargement (P<.05). CONCLUSIONS: The apical enlargement 35.05 with CM heat-treatment instruments using reciprocating and rotary motion reduced the percentage of debris and untouched root canal surface, without causing deviations or procedural errors. The protocol of greater apical enlargement favors the cleaning of the root canals in both kinematics. Preparation by the reciprocating system was faster than by the rotary system.


Asunto(s)
Instrumentos Dentales , Cavidad Pulpar/diagnóstico por imagen , Níquel , Preparación del Conducto Radicular/instrumentación , Titanio , Análisis de Varianza , Cavidad Pulpar/anatomía & histología , Diseño de Equipo , Calor , Humanos , Ensayo de Materiales , Valores de Referencia , Reproducibilidad de los Resultados , Estadísticas no Paramétricas , Propiedades de Superficie , Microtomografía por Rayos X
16.
Swiss Dent J ; 129(11): 922-928, 2019 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-31460731

RESUMEN

The aim of this study was to evaluate the performance of Galilean and Keplerian loupes in the endodontic lumen with and without integrated light. Although the use of an operating microscope is widely recommended in endodontics it is uncertain whether an adequate loupe system with coaxial light source might replace the microscope for some endodontic work. Twenty-four dentists (age 27­64 years) underwent a miniaturized visual test inside the endodontic lumen of a natural molar: at the canal entrance, 5 mm inside the canal, and at the apex. The tooth was mounted in a phantom head in a simulated clinical setting. The naked eye (negative) and the microscope 6× (positive) served as control groups, and Galilean loupes 2.5× and Keplerian loupes 4.3× with and without a coaxial light source as experimental groups. A structure of 0.05 mm corresponding to the smallest instrument (06) was the threshold for sufficient vision. The loupe type, coaxial light source and the dentists' age had a statistically significant influence at all locations. None of the loupes helped to visualize structures at the apex. At the canal entrance, the visual threshold was reached by dentists < 40 years with Galilean loupes, by dentists ≥ 40 years with Keplerian loupes, with and without coaxial light. Dentists < 40 years detected structures < 0.05 mm inside the root canal with Keplerian loupes and coaxial light. The microscope offered highly superior results. The naked eye was insufficient to reach the visual threshold at any location.


Asunto(s)
Instrumentos Dentales , Odontólogos , Endodoncia , Microscopía/instrumentación , Visión Ocular , Adulto , Estudios de Casos y Controles , Atención Odontológica , Femenino , Humanos , Lentes , Masculino , Persona de Mediana Edad , Miniaturización , Pruebas de Visión
17.
J Endod ; 45(10): 1237-1241, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31420109

RESUMEN

INTRODUCTION: The goal of this study was to compare the cyclic fatigue resistance of 5 heat-treated nickel-titanium files in reciprocating movement with the same tip size and different cross sections. METHODS: Five groups (WaveOne [Dentsply, Ballaigues, Switzerland], WaveOne GOLD [Dentsply], RECIPROC [VDW, Munich, Germany], RECIPROC BLUE [VDW GmbH, Munich, Germany], and TF [Sybron Endo, Glendora, CA] Adaptive) of 24 files each of the rotary files were examined. Cyclic fatigue resistance was compared between groups by determining the time needed to fracture and the number of cycles to failure in a cyclic fatigue testing device with 2 different curvatures, the first with a 5-mm radius of curvature and a 60° angle and the second with a double curvature, coronal curvature of 60° angle and a radius of 5 mm, and an apical curvature of 70° angle and a 2-mm radius. Scanning electron microscopic evaluation was performed at the fracture sites to investigate the types of fracture. RESULTS: RECIPROC BLUE group had a higher mean time to fracture followed by RECIPROC and WaveOne GOLD for both single and double curvature. WaveOne had a higher mean time to fracture in a single curvature canal than TF Adaptive, whereas the opposite was true for a double curvature canal. Both RECIPROC groups were significantly greater in cyclic fatigue resistance in comparison with all other groups (P < .05). WaveOne GOLD was significantly greater than the WaveOne and TF Adaptive groups (P < .05). CONCLUSIONS: RECIPROC BLUE files exhibited significantly greater cyclic fatigue resistance compared with other files tested in an S-shaped artificial canal.


Asunto(s)
Instrumentos Dentales , Níquel , Preparación del Conducto Radicular , Titanio , Diseño de Equipo , Falla de Equipo , Alemania , Calor , Ensayo de Materiales , Estrés Mecánico
18.
J Endod ; 45(9): 1135-1141, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31350048

RESUMEN

INTRODUCTION: The purpose of this study was to evaluate the ability of the XP-endo Shaper instrument (FKG Dentaire, La Chaux-de-Fonds, Switzerland) during the removal of root fillings from oval-shaped canals. M-Wire Reciproc and Reciproc Blue systems (VDW, Munich, Germany) were used as reference instruments for comparison, and micro-computed technology was used as an analytical tool. METHODS: Thirty mandibular incisors with oval-shaped canals were matched based on similar anatomic features of the canal (eg, volume, aspect ratio, and 3-dimensional configuration) after scanning procedures. The canals were prepared with M-Wire Reciproc R25 instruments and filled with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany) using the continuous wave of condensation technique. Then, the sample was allocated into 3 experimental groups (n = 10) according to the retreatment protocol used: M-Wire Reciproc, Reciproc Blue, and XP-endo Shaper. M-Wire Reciproc R25, Reciproc Blue R25, and XP-endo Shaper instruments were used to remove the root fillings. Apical enlargement was performed with M-Wire Reciproc R40, Reciproc Blue R40, and BioRace BR5 (FKG Dentaire) instruments. Each sample was scanned after each endodontic procedure. The volume of remaining root filling material was quantified before and after apical enlargement. The percentage volumes of root filling reduction in relation to the instrumented canals at both time points (before and after apical enlargement) were calculated and considered for statistical analysis. Data were analyzed statistically with a significance level of 5%. RESULTS: Reciproc Blue presented significantly lower removal of filling material compared with the XP-endo Shaper (Tukey test, P < .05). No difference was detected either between M-Wire Reciproc and Reciproc Blue (Tukey test, P > .05) or M-Wire Reciproc and XP-endo Shaper (Tukey, P > .05). The increase of apical enlargement significantly improved the removal of root fillings from the root canals (P < .05); this effect was similar for all systems (time point × file system, P > .05). CONCLUSIONS: The XP-endo Shaper instrument showed a higher percentage of root filling removal, but no differences were observed comparing M-Wire Reciproc with the XP-endo Shaper or Reciproc Blue. The increase of apical enlargement improved the removal of root fillings in all groups. None of them was able to render root canals completely free from root fillings.


Asunto(s)
Materiales de Obturación del Conducto Radicular , Obturación del Conducto Radicular , Instrumentos Dentales , Cavidad Pulpar , Alemania , Gutapercha , Humanos , Retratamiento , Preparación del Conducto Radicular , Microtomografía por Rayos X
19.
Int Endod J ; 52(12): 1768-1772, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31306497

RESUMEN

AIM: To compare the martensitic transformation temperatures and torsional resistance behaviour of classic M-Wire Reciproc and Reciproc blue files (VDW, Munich, Germany). METHODOLOGY: M-Wire classic Reciproc R25 and Reciproc blue R25 instruments were used. Transformation temperatures were determined by differential scanning calorimetry (DSC-DSC 60, Shimadzu, Kyoto, Japan). Three samples with approximately 20 mg of each system were cooled to -120 °C and then heated to 100 °C and then cooled to -100 °C at a rate of 10 °C min-1 . The maximum torque values and angular deflection until fracture of new instruments (n = 10) were measured according to ISO 3630-1. Results were analysed statistically using the Student's t-test at a significance level of P < 0.05. RESULTS: DSC results revealed the absence of martensitic transformation for Reciproc instruments in the temperature range analysed. In both systems, the instruments were composed of a mixture of R-phase and austenite at room temperature. After torsional tests, Reciproc blue had significantly lower values for mean maximum torque at rupture (P < 0.05), although the angular deflection values were significantly higher than the Reciproc classic group (P < 0.05). CONCLUSIONS: Both Reciproc and Reciproc blue instruments were composed of a mixture of R-phase and austenite. Reciproc Blue instruments had a greater angle of rotation to fracture but a lower torque to failure than M-Wire Reciproc instruments.


Asunto(s)
Instrumentos Dentales , Preparación del Conducto Radicular , Diseño de Equipo , Alemania , Humanos , Ensayo de Materiales , Estrés Mecánico , Temperatura Ambiental , Titanio
20.
J Contemp Dent Pract ; 20(6): 697-701, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-31358712

RESUMEN

AIM: This study aims to investigate the influence of temperatures of 20 °C and 37 °C on the resistance to cyclic fatigue of NiTi instruments with different heat treatments, as tested in severely curved simulated canals. MATERIALS AND METHODS: Seventy-two instruments were distributed according to the temperature used (20 °C and 37 °C): XP-endo Shaper (30/0.01), ProDesign Logic (30/0.05), and iRaCe (30/0.04). The instruments were rotated freely until the occurrence of fracture inside an artificial severely curved stainless steel canal, which had a 90° angle of curvature and a curvature radius of 5 mm. Kolmogorov-Smirnov, Wilcoxon, ANOVA, and Kruskal-Wallis tests were performed. A p value of <0.05 was considered statistically significant. RESULTS: XP-endo Shaper instruments presented higher NCF values and time to failure compared with ProDesign Logic and iRaCe instruments at 20 °C and 37 °C (p < 0.001). CONCLUSION: Within the limitations of this study, the results show that the body temperature (37 °C) significantly lowers the resistance to cyclic fatigue of all instruments compared with 20 °C. CLINICAL SIGNIFICANCE: Body temperature is an important factor in the results of cyclic fatigue tests.


Asunto(s)
Níquel , Titanio , Instrumentos Dentales , Diseño de Equipo , Fatiga , Calor , Humanos , Preparación del Conducto Radicular , Temperatura Ambiental
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