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1.
Proc Inst Mech Eng H ; : 954411921990138, 2021 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-33482709

RESUMEN

Post-treatment coronal hermetic seal of the root canal opening prevents the food or saliva which assist to achieve successful endodontic treatment. Gutta-percha is filled in the inner canal, that is, from cervical third to apical third. Gutta-percha does not provide the hermetic seal because it does not bound with dentine walls. Various new restorative materials have been developed in the last 6-7 decade but drawback related to the polymerization shrinkage of the composite resin remains a clinical problem. In general, dental composites having volumetric shrinkage of the material depends on its formulation and curing conditions. In this article, the effect of this polymerization shrinkage on the tooth structure has been studied.

2.
Proc Inst Mech Eng H ; 233(8): 839-848, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31165678

RESUMEN

During root canal shaping, pain could result from the high level of force or vibration generated. This could be related to file kinematics or geometry. In the present study, a comparison is made between forces and vibrations generated by endodontic files having three different kinematics. Square pillar resin blocks were used as simulated root canals to study forces and vibrations generated by the file having reciprocating motion (WaveOne Gold), transline motion (Self-Adjusting File), and rotary motion (2Shape). The forces and vibrations were measured using the dynamometer and accelerometer, respectively. Recorded time domain signals were processed in MATLAB to calculate the root mean square value. A one-way analysis of variance and Tukey's test for post hoc comparison at 95% confidence interval were applied over the root mean square data of different files. From a statistical analysis of the file systems, the null hypotheses could not be accepted (P < 0.05) as 95% of the confidence interval. Differences between the means were statistically significant. The root mean square values of force and vibration for WaveOne Gold significantly exceeded those of Self-Adjusting File, 2Shape1, and 2Shape2 while the root mean square values of vibration for 2Shape1 and 2Shape2 were significantly less than the Self-Adjusting File; however, the root mean square value of force for the 2Shape2 was significantly more than for the Self-Adjusting File. Under the present experimental conditions, significant differences in the root mean square values of force and vibration of the three endodontic files of different kinematics have been observed. The WaveOne Gold file system generated higher apical force and vibration than the transline and rotary file system.


Asunto(s)
Preparación del Conducto Radicular/instrumentación , Vibración , Fenómenos Biomecánicos , Dolor/etiología , Preparación del Conducto Radicular/efectos adversos , Rotación
3.
Proc Inst Mech Eng H ; 232(8): 787-795, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30014778

RESUMEN

In cases of teeth with unusual morphology like calcified pulp canal, guided endodontic treatment is suggested. An endodontic guide which navigates burs according to a preplanned path is used. Existing approaches of endodontic guide design are based on visual observation and analysis of tomographic scan of teeth. Hence, they are time-consuming and expert-dependent. Computer-aided design-based methodology was employed to design and fabricate a customized endodontic guide. A cone beam computed tomographic scan with MIMICS software was used to create a solid model of the teeth. The solid model generated was sliced through the developed program in MATLAB. The geometric centers of consecutive slices were joined to plot the root canals central axis. To gauge the optimum bur angulation for guide design, a straight line fitted in the data set of the geometric center helped create minimally invasive access. Methodology involved simulated verification of the drill path to judge the accuracy and feasibility of root canal access cavity preparation. Next, endodontic guides for extracted teeth were designed and fabricated using a three-dimensional printer, followed by guided root canal access cavity preparation for extracted teeth. To validate the proposed methodology, using a MATLAB image processing tool box, the deviation between the prepared root canal access cavity axis and root canal axis was analyzed in radiographs of post-treated teeth. The deviation between the tool path axis and root canal axis in simulated root canals was found to be not more than 0.210 ± 0.04 mm. The deviation between the axis of the planned root canal access cavity and the prepared root canal access cavity was 0.07 ± 0.02 mm. The proposed method reveals encouraging results for endodontic guide design.


Asunto(s)
Diseño Asistido por Computadora , Cavidad Pulpar/cirugía , Preparación del Conducto Radicular/métodos , Programas Informáticos , Tomografía Computarizada de Haz Cónico , Cavidad Pulpar/diagnóstico por imagen , Diseño de Equipo , Preparación del Conducto Radicular/instrumentación
4.
J Dent Sci ; 13(3): 184-189, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30895119

RESUMEN

Background/purpose: The focus of this study was to find a correlation between the forces and vibrations during root canal shaping. This can be used to predict the fracture of the self-adjusting file (SAF) in root canal shaping. Materials and methods: Forty J-shaped resin blocks were used in this study. Simulated root canals of resin blocks were prepared with the SAF. Force and vibration during root canal shaping were measured by dynamometer and accelerometer respectively. The recorded time domain signal of force and vibration were transformed to frequency domain signals. Frequency domain signals had been used for correlation study between force and vibration amplitude. The root mean square (RMS) value of force and vibration signature for new file and file just before failure were statistically compared using t-test at 95% confidence interval (CI). Results: Vibrations generated during root canal shaping exhibited positive linear correlation (r = 0.9173) with force exerted by the SAF on the root canal. It means vibration has strong correlation with force. The RMS values of force and vibration increase significantly (P < 0.05) just before the fracture. Conclusion: From force and vibration analysis of SAF it was concluded that the vibration is well associated with force applied by the SAF on root canal. Therefore, the trend of force variation was reflected in the vibration signature. The sudden increment in vibration was the symptom of bulge formation and the end of useful life of the SAF.

5.
J Conserv Dent ; 20(2): 81-85, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28855752

RESUMEN

OBJECTIVES: To compare the relative axis modification and canal concentricity after glide path preparation with 20/0.02 hand K-file (NITIFLEX®) and 20/0.04 rotary file (HyFlex™ CM) with subsequent instrumentation with 1.5 mm self-adjusting file (SAF). MATERIALS AND METHODS: One hundred and twenty ISO 15, 0.02 taper, Endo Training Blocks (Dentsply Maillefer, Ballaigues, Switzerland) were acquired and randomly divided into following two groups (n = 60): group 1, establishing glide path till 20/0.02 hand K-file (NITIFLEX®) followed by instrumentation with 1.5 mm SAF; and Group 2, establishing glide path till 20/0.04 rotary file (HyFlex™ CM) followed by instrumentation with 1.5 mm SAF. Pre- and post-instrumentation digital images were processed with MATLAB R 2013 software to identify the central axis, and then superimposed using digital imaging software (Picasa 3.0 software, Google Inc., California, USA) taking five landmarks as reference points. Student's t-test for pairwise comparisons was applied with the level of significance set at 0.05. RESULTS: Training blocks instrumented with 20/0.04 rotary file and SAF were associated less deviation in canal axis (at all the five marked points), representing better canal concentricity compared to those, in which glide path was established by 20/0.02 hand K-files followed by SAF instrumentation. CONCLUSION: Canal geometry is better maintained after SAF instrumentation with a prior glide path established with 20/0.04 rotary file.

6.
J Conserv Dent ; 19(2): 138-42, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27099419

RESUMEN

AIM: Current ex vivo study compared fracture resistance of teeth instrumented using 5 endodontic files, filled with Gutta-percha and AH Plus. MATERIALS AND METHODS: Sixty freshly extracted, single-rooted mandibular premolars were acquired and decoronated to obtain 15 mm segments. These samples were randomly divided into six groups (n = 10). Group 1 served as the control containing untreated samples (without instrumentation or filling). In Groups 2-6, samples were instrumented using rotary (Universal ProTaper and Revo-S), reciprocating (WaveOne and RECIPROC(®)), and self-adjusting file (SAF), respectively. Following instrumentation, the samples were filled by lateral compaction with Gutta-percha and AH Plus. A week later, after the sealer was completely set, a vertical load was applied to the specimen's canal in each group until fracture. The loads required for fracture were recorded, and statistical analysis was performed. RESULTS: The mean fracture load differed significantly among the groups (P < 0.01; one-way ANOVA). Tukey's post-hoc tests revealed that the fracture resistance was similar in the control and SAF groups (P > 0.05) and was significantly higher than that of the 2 rotary and reciprocating groups (P < 0.01). CONCLUSION: The samples instrumented by the SAF exhibited a better fracture resistance.

7.
Int J Esthet Dent ; 9(4): 526-35, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25289387

RESUMEN

The aim of this article was to report the clinical case of a male patient of 20 years with hyperpigmented gingiva and moderate fluorosis, whose smile was reestablished by the use of a laser assisted depigmentation procedure, an enamel microabrasion technique, followed by at-home bleaching and subsequent remineralization therapy. The association of these techniques presented excellent results and the patient was satisfied. All techniques are painless, fast and easy to perform, in addition to preserving the hard and soft dental structure. Treatment showed immediate and permanent results; these techniques must be divulged among professionals and their patients.


Asunto(s)
Microabrasión del Esmalte/métodos , Fluorosis Dental/terapia , Enfermedades de las Encías/cirugía , Hiperpigmentación/cirugía , Terapia por Láser/métodos , Fluoruro de Fosfato Acidulado/uso terapéutico , Peróxido de Carbamida , Caseínas/uso terapéutico , Mezclas Complejas/uso terapéutico , Profilaxis Dental/instrumentación , Dentífricos/uso terapéutico , Microabrasión del Esmalte/instrumentación , Estudios de Seguimiento , Humanos , Terapia por Láser/instrumentación , Láseres de Semiconductores/uso terapéutico , Masculino , Satisfacción del Paciente , Peróxidos/uso terapéutico , Blanqueamiento de Dientes/instrumentación , Blanqueamiento de Dientes/métodos , Blanqueadores Dentales/uso terapéutico , Remineralización Dental/métodos , Urea/análogos & derivados , Urea/uso terapéutico , Adulto Joven
8.
Korean J Pain ; 26(4): 347-55, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24156000

RESUMEN

Pain and pain control are important to the dental profession because the general perception of the public is that dental treatment and pain go hand in hand. Successful dental treatment requires that the source of pain be detected. If the origin of pain is not found, inappropriate dental care and, ultimately, extraction may result. Pain experienced before, during, or after endodontic therapy is a serious concern to both patients and endodontists, and the variability of discomfort presents a challenge in terms of diagnostic methods, endodontic therapy, and endodontic knowledge. This review will help clinicians understand the basic neurophysiology of pulpal pain and other painful conditions of the dental pulp that are not well understood.

9.
J Conserv Dent ; 14(2): 164-8, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21814359

RESUMEN

AIMS: This in vitro study compared the effects of different layering techniques on the microleakage of silorane-based resin composite using confocal laser scanning microscope. MATERIALS AND METHODS: Forty caries free premolars extracted for orthodontic reasons were used. A class V cavity was prepared on the buccal surface in each of the premolars, with the gingival margin of the cavity being 1 mm above cementoenamel junction. The cavities were restored with a silorane-based resin composite (Filtek(™) P90 Silorane Low Shrink Restorative, 3M ESPE) using two different layering techniques - split incremental and oblique layering technique. All samples were subjected to 1000 thermal cycles of 5°C/55°C in water with a 30 second dwell time, and after the procedure, the teeth were immersed in 0.6% aqueous rhodamine dye for 48 hours. Sectioned samples were examined under a Confocal Fluorescence Imaging Microscope (Leica TCS-SP5, DM6000-CFS) at 10× magnification, and microleakage scores were analyzed statistically using paired "t" test and Mann-Whitney test. Width of interface between the tooth surface and resin composite was measured using a digital scale (Snagit digital scale). RESULTS: Microleakage was seen along the entire perimeter of restoration irrespective of the layering technique used. The microleakage score was same in both the groups. Statistical analysis of width of interface showed significant difference between the two layering techniques. The width was significantly less in split incremental technique, indicating less polymerization shrinkage. CONCLUSIONS: This in vitro study showed that the silorane-based resin composite shows microleakage irrespective of the layering technique used for class V cavities. However, this problem can be minimized significantly by using split incremental technique for restoration of class V lesions.

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