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1.
Niger J Clin Pract ; 24(4): 505-510, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33851671

RESUMO

Objective: To evaluate the effect of varying ferrule height and distribution on the fatigue resistance and fracture strength of endodontically treated premolars. Materials and Method: Thirty-two extracted human premolars were endodontically treated and prepared to receive all-ceramic crowns. Teeth were randomly divided into two groups. The occluso-cervical height was reduced to 2 mm and 4 mm for the 1st and 2nd groups, respectively. According to the ferrule distribution, samples in each group were randomly divided into two subgroups with inadequate ferrule on 1 or 2 proximal walls, respectively. Coronal tooth structure was built-up to 4 mm using a core build-up material retained by a fiber post. The CEREC system (Sirona) was used to design and mill lithium-disilicate crowns. All posts and crowns were cemented to their respective teeth using self-adhesive universal resin cement. All crowns were subjected to cyclic loading in a universal testing machine (Instron) (20-100N, 100,000 cycles, 20Hz). After fatigue, crowns were loaded to fracture. Fracture load data were analyzed using two-way ANOVA at α = 0.05. Results: All crowns passed the fatigue testing without any signs of fracture or crack. Two-way ANOVA revealed a statistically significant effect of the number of missing walls (P < 0.05) on the fracture load, but not the ferrule height or the interaction terms. Samples with one missing wall showed higher fracture load in comparison to samples with two missing walls. Conclusion: The number of missing walls, not the ferrule height, has a significant effect on the fracture load of the lithium-disilicate crowns restoring endodontically treated premolars.


Assuntos
Técnica para Retentor Intrarradicular , Fraturas dos Dentes , Dente não Vital , Dente Pré-Molar , Resinas Compostas , Coroas , Falha de Restauração Dentária , Análise do Estresse Dentário , Humanos
2.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 39(1): 115-120, 2021 Feb 01.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-33723947

RESUMO

Many patients with large-area tooth defect need cast post-core crown restoration. However, the color defect of the cast post-core will affect the final restorative result, especially that of the anterior teeth. A new technology of color masking by applying CERAMAGE polymeric porcelain to the cast metal post-core surface improves the color of a full-ceramic restoration of anterior teeth and may provide a new alternative for the aesthetic repair of anterior teeth with a large area of defective tooth.


Assuntos
Porcelana Dentária , Técnica para Retentor Intrarradicular , Cerâmica , Coroas , Estética Dentária , Humanos
3.
J Med Life ; 14(1): 81-85, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33767790

RESUMO

This study aims to determine whether the design of resin posts reinforced with glass fiber (FRC) and Reporfost (Angelus, Londrina, PR, Brazil) significantly improves the fracture resistance of endodontically treated teeth restored through this method.A batch of 30 maxillary monoradicular teeth (15 central incisors, 15 canines) were treated endodontically by step-back technique (apical enlargement 40-K file) sealed with Sealapex (Kerr Corporation, Orange, US) and gutta-percha by lateral condensation, cold. They were divided into two equal groups, prepared for cementing the FRC posts. The Exacto posts (Angelus, Londrina, PR, Brazil) in group 1 and the Reforpost posts (Angelus; Londrina; PR, Brazil) were cemented with dual cure resin cement Breeze Self-Adhesive Resin Cement (Pentron Clinical, Orange, US). Fracture resistance testing was performed on the crown-apical axial direction, using the Hounsfield / Tinius Olsen H1-KS, PA, USA mechanical testing apparatus. The behavior of each tooth-post assembly was recorded as a graph. The statistical analysis was done using one way ANOVA (α=0.05). The differences between the Exacto post group and the Reforpost post group are not statistically significant (p = 0.466). The maximum force recorded was 970 N and the minimum 186N. The mean force at which the fracture occurred was approximately 500N for both groups. The strain test showed that modifying the Reforpost post design did not improve the fracture resistance parameters of the tooth-post assembly through increasing the surface friction or maintaining adhesion to the walls of the root dentin.


Assuntos
Resinas Compostas/uso terapêutico , Vidro/química , Técnica para Retentor Intrarradicular , Fraturas dos Dentes/terapia , Dente não Vital/terapia , Humanos , Teste de Materiais , Estresse Mecânico
4.
Int J Prosthodont ; 34(1): 120-125, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33570528

RESUMO

This clinical report presents the use of a modified polyetheretherketone (PEEK) post and core in order to support a lithium disilicate ceramic crown for a maxillary lateral incisor. When considering post-and-core restorations, material flexibility is essential to prevent root fractures. The low elastic modulus of PEEK (4 GPa) could result in lower root fracture rates, preserving tooth structure and favoring tooth re-restoration if the post fractures. PEEK is biocompatible, presents adequate bond strength with dentin when bonded with a resin cement, and can be used under ceramic restorations because of its white, esthetic color. PEEK posts and cores could also cost less when fabricated using common laboratory procedures. Polyetheretherketone (PEEK) posts and cores could be a viable alternative to rigid cast or zirconia posts, or even to fiber-reinforced composite posts, especially when combined with lithium disilicate crowns.


Assuntos
Técnica para Retentor Intrarradicular , Cerâmica , Resinas Compostas , Coroas , Porcelana Dentária , Falha de Restauração Dentária , Análise do Estresse Dentário , Estética Dentária , Cetonas , Polietilenoglicóis
5.
J Prosthet Dent ; 125(4): 674.e1-674.e7, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33431176

RESUMO

STATEMENT OF PROBLEM: Light transmitted deep into the root canal is an important parameter to increase bonding of the cement to the post and dentin. Glass fiber posts seem to be an option to increase transmitted light, but literature on the light transmittance profile and power transmission to deep canal regions is lacking. PURPOSE: The purpose of this in vitro study was to evaluate light delivered by 2 types of fiberglass posts submitted to different surface treatments and to evaluate the bond strength. MATERIAL AND METHODS: Whiteposts and Superposts were allocated to 4 groups: no surface treatment, surface treatment with 24% hydrogen peroxide, surface treatment with silane, and surface treatment with 24% hydrogen peroxide plus silane. The total light transmitted by the posts was measured by using an integrating sphere to collect the diffuse light. The light profile that was laterally delivered to the post was measured with a power detector equipped with an optical fiber probe. The bond strength was measured with the push-out test. Scanning electron microscopy was used to evaluate the surface treatments. The light transmission data were analyzed by using a generalized linear model and the Bonferroni test and the bond strength values were evaluated by using ANOVA and the Tukey test (α=.05). RESULTS: The cervical third presented the highest transmission (74.1% for Whiteposts and 74.6% for Superposts), followed by the middle (20.9% for Whiteposts and 20.4% for Superposts) and apical (5.0% for both Whiteposts and Superposts) thirds. Superposts led to higher bond strength than Whiteposts (9.73 ±5.89 and 8.48 ±4.99 MPa, respectively). Surface treatment with silane and hydrogen peroxide plus silane afforded similar bond strength (11.4 ±6.4 and 10.7 ±5.6 MPa, respectively), which was higher as compared with the bond strength obtained after surface treatment with hydrogen peroxide. For both post types, the bond strength decreased from the cervical (12.2 ±6.0 MPa) to the middle (9.7 ±5.0 MPa) and apical (6.5 ±3.6 MPa) thirds. CONCLUSIONS: Light transmission and bond strength decreased from the cervical to the apical third. Surface treatment impacted bond strength; light transmission through Whiteposts was slightly higher than light transmission through Superposts.


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Dentina , Vidro , Teste de Materiais , Cimentos de Resina
6.
Clin Oral Investig ; 25(2): 417-440, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33417064

RESUMO

OBJECTIVES: This systematic review and meta-analysis compared the effects of immediate and delayed post space preparation on apical sealing. MATERIALS AND METHOD: Two independent authors conducted a systematic search (PubMed/Medline, Cochrane Library, and other databases, until February 2020) and a risk of bias evaluation. Only in vitro studies that compared the effects of immediate and delayed post space preparations on apical filling and adhesion of the post were eligible. RESULT: Of the 742 articles retrieved, 32 were included. Most of the studies used single-rooted human teeth and rotary files for root canal preparation, a single-cone technique for the filling protocol, and rotary instruments for post space preparation. Various delayed preparation times were evaluated: 8-72 h, 5-30 days (mainly 7 days), and 4 months. In nine studies, the delayed groups showed more apical leakage, while four studies reported more leakage in the immediate groups; ten studies found no significant difference. One study found more bacterial penetration in the delayed group, whereas three studies showed no significant difference. One study reported more voids in the delayed group, while another found no such difference. Three studies showed better post-bond strength in the delayed group, one in the immediate group, whereas three found no significant difference in post-bond strength. Three studies employing varied sealers for root canal fillings were considered for meta-analysis. Two subgroup analyses were also performed (one concerning the use of resin-based sealers (AH Plus), another for zinc oxide-eugenol-based sealers). The results of the meta-analysis showed that a delayed post space preparation led to a significantly higher apical leakage than an immediate preparation (mean difference = 0.41 mm, confidence interval = 0.24-0.59, p < 0.001). CONCLUSION: Delayed post space preparation seems to negatively influence apical sealing; however, further studies are needed to determine the influence of the timing of post space preparation on the other parameters. CLINICAL RELEVANCE: Immediate post space preparation may be the safest clinical choice to prevent apical leakage.


Assuntos
Infiltração Dentária , Técnica para Retentor Intrarradicular , Materiais Restauradores do Canal Radicular , Resinas Epóxi , Guta-Percha , Humanos , Obturação do Canal Radicular , Preparo de Canal Radicular
7.
J Oral Sci ; 63(2): 125-128, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33361691

RESUMO

PURPOSE: To evaluate the degree of conversion (DoC) of self-adhesive resin luting cements when irradiated through different fiber post lengths. METHODS: A total of 60 teeth were sectioned to achieve lengths of 4 mm, 7 mm, and 10 mm, while 60 fiber posts were trimmed to give 3 mm, 6 mm, and 9 mm lengths. Post space was created to accommodate the fiber post and 1 mm of luting cement apically. Two self-adhesive resin luting cements (Multilink Speed and RelyX U200) were used. A total of four cycles of 20 s irradiation was done with an attenuated total reflectance Fourier transform infrared spectroscopy reading between each cycle. RESULTS: The mean ± standard deviation DoC achieved with a light-emitting diode and quartz tungsten halogen for Multilink Speed was 67.4 ± 2.7% and 72.4 ± 4.0%, respectively, while for RelyX U200, the corresponding values were 56.5 ± 2.7% and 62.0 ± 3.8%, respectively. For Multilink Speed, there was no significant difference between the control and the 3 mm group, while for RelyX U200, no significant difference was found between the 6 mm and 9 mm groups. All the other groups showed significant differences. CONCLUSION: The DoC reduced as the post length increased.


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Cimentos Dentários , Materiais Dentários , Cimentos de Ionômeros de Vidro , Teste de Materiais , Cimentos de Resina
8.
Braz Dent J ; 31(6): 582-588, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33237228

RESUMO

This study evaluated the dimensions of intraradicular posts using a new cone beam CT (CBCT) software, and verified the potential of blooming artifact reduction. Sixty-three single-rooted human teeth were shaped, obturated, prepared for intracanal post placement and distributed into three groups: G1: anatomically customized prefabricated glass fiber posts; G2: low-fusion alloy posts; G3: gold alloy posts. After post fabrication and luting with RelyX U200®, specimens were sectioned axially at 9 mm from the root apex, and markings were made on the root surfaces (X-, Y- and Z-axes). The dimensions of the original posts (control group) were measured using a digital micrometer. CBCT scans of the teeth were obtained using a PreXion 3D Elite® scanner. Posts were measured on CBCT scans using DICOM files and the e-Vol DX software. A specific filter, Blooming Artefact Reduction (BAR), was developed to analyze intracanal posts. Statistical data were evaluated using the Van de Waerden nonparametric analysis of variance and, after that, normalized data were analyzed using the Tukey test. The level of significance was set at α = 5%. The measures of the anatomical prefabricated, low-fusion alloy and gold alloy intracanal posts obtained using the e-Vol DX CBCT software and a micrometer were not significantly different (p>0.05). The use of the BAR filter of the e-Vol DX software application did not induce any dimensional differences on CBCT scans of intracanal posts when compared with measurements made with a micrometer on original posts. The use of the BAR filter eliminated blooming artifacts.


Assuntos
Artefatos , Técnica para Retentor Intrarradicular , Tomografia Computadorizada de Feixe Cônico , Humanos , Software , Raiz Dentária
9.
Adv Clin Exp Med ; 29(9): 1111-1116, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33001590

RESUMO

BACKGROUND: The primary reason for using a post is to retain the core with the objective to restore the missing coronal tooth structure. To achieve optimum results, the materials that are used to restore endodontically treated teeth should have physical and mechanical properties that are similar to that of dentin. OBJECTIVES: To characterize the strength parameters of fiber-reinforced composite (FRC) posts with the application of a three-point test. The mean fracture load, flexural strength and flexural modulus were taken into consideration. MATERIAL AND METHODS: For the three-point strength tests, 5 kinds of fiberglass root-posts were used: GC Fiber Post (GC America, Alsip, USA), Mirafit White (Hager Werken, Duisburg, Germany), Innopost (InnoTech, Verona, Italy), Rebilda Post (Voco, Cuxhaven, Germany), and EverStick Post (GC Europe, Leuven, Belgium). For each system, 15 FRC posts were tested. All posts had the same diameter, length and shape. The three-point test was carried out in accordance with ISO 10477:2004, using the Instron-5944 testing machine (Instron, Norwood, USA). The test was carried out until the sample was broken. RESULTS: The highest force values (67.6 N) were recorded for the GC posts, and the lowest force required to break the sample (29.6 N) was noted for the EverStick Posts. In the case of bending strength, the highest values were also recorded for GC posts (912.4 MPa). Low bending strengths were obtained for the Mirafit White posts (537.2 MPa); however, the EverStick Posts were the weakest (436.2 MPa). Rebilda posts showed the highest modulus of elasticity - 31.1 GPa. The lowest values of the elastic modulus were registered for EverStick Posts - 12.5 GPa. CONCLUSIONS: There were statistically significant differences in fracture loads, flexural strengths and flexural modulus of the FRC-post systems tested. Individually polymerized FRC material showed lower flexural properties than compared prefabricated FRC posts.


Assuntos
Cavidade Pulpar , Técnica para Retentor Intrarradicular , Teste de Materiais
10.
J Indian Soc Pedod Prev Dent ; 38(3): 253-258, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33004723

RESUMO

Background: In cases where there is an extensive loss of crown structure, these treatments require intracanal posts placement for retention as occlusal forces make the tooth structure weak and prone to fracture. Thus, restoration of primary anterior teeth, followed by post placement and cementation with pediatric zirconia crowns helps withstand masticatory forces to a greater extent. Aim: This in vitro study evaluates the compressive strength of two different post systems in the primary anterior teeth, restored with pediatric zirconia crowns. Materials and Methods: The present study was an in vitro, experimental, comparative study, with a study sample selected using a convenience sampling method. Forty-five primary anterior teeth were obturated and restored with enhanced omega-shaped loop and reinforced glass-fiber posts were cemented with pediatric zirconia crowns. The compressive strength and the type of fracture were evaluated for each group. Results: This study demonstrated that the glass-fiber posts had a higher compressive strength, although omega-shaped posts showed a higher presence of favorable fracture. Conclusion: Retentive omega-shaped loops and reinforced glass-fiber posts were both capable of withstanding high fracture loads. The addition of cemented pediatric zirconia crown on decayed primary anterior teeth restored with post systems helped withstand the load to a greater extent.


Assuntos
Técnica para Retentor Intrarradicular , Fraturas dos Dentes , Criança , Força Compressiva , Coroas , Humanos , Zircônio
11.
Shanghai Kou Qiang Yi Xue ; 29(3): 325-328, 2020 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-33043354

RESUMO

PURPOSE: To analyze the effect and long-term success rate of using glass fiber post or metal post in restoration of anterior tooth defect. METHODS: One hundred and fifty cases with anterior tooth defects were chosen after root canal therapy in our hospital. According to different material being chosen, the patients were divided into fiber post group and metal post group with 75 cases in each group. Local gingival sulcus fluid (GCF) levels and alkaline phosphatase (ALP) level in gingival sulcus liquid were measured and compared 4 weeks, 6 months, 1 year, 2 years and 3 years after restoration. Restoration integrity, edge fitness and color matching of two groups were compared after follow-up for 3 years. The data were analyzed with SPSS 19.0 software package. RESULTS: Four weeks, 6 months, and 1 year after restoration, local GCF, ALP levels significantly elevated in both groups. The fiber post group showed more significant elevated levels of GCF and ALP than the metal post group (P<0.05). After 2 and 3 years, the difference between the two groups was not significant. The gingival color matching degrees were significantly better in the glass fiber post group after 1 year compared with that in the metal post group(P<0.05). The success rate of metal post group was significantly higher than that of fiber post group 3 years after restoration(P<0.05). CONCLUSIONS: Fiber post and metal post both have satisfactory restoration result for tooth defect in anterior teeth area. However, the use of precious metal alloy post may reduce the possibility of microleakage between tooth-prosthesis surfaces.


Assuntos
Técnica para Retentor Intrarradicular , Vidro , Humanos , Metais , Tratamento do Canal Radicular
12.
Am J Dent ; 33(5): 227-234, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33017523

RESUMO

PURPOSE: To evaluate the influence of different post-endodontic techniques on the fatigue survival and biomechanical behavior of crowned restored central incisors. METHODS: The crowns of 69 bovine incisors were cut, and the roots were treated endodontically and assigned randomly into three groups (n=23): resin composite buildup (BUP), glass fiber post-retained resin composite buildup (GFP), and cast post-and-core (CPC). They received full crown preparation with 2 mm ferrule, and a leucite-reinforced ceramic crown was cemented adhesively. Three specimens from each group were tested monotonically. The remaining specimens were subjected to the stepwise stress fatigue test until fracture or suspension after 1.5 x 106 cycles in a chewing simulator. The load and step at which each specimen failed were analyzed by Kaplan-Meier and Mantel-Cox (log-rank test) statistics, followed by multiple pairwise comparisons, at 5% significance level. The three groups tested (BUP, GFP, and CPC) were 3D modeled (Rhinoceros 4.0) and the maximum principal stress (MPa) criteria were used to calculate the results using FEA. RESULTS: There was no statistical difference between the treatments regarding the load or the number of cycles (Mantel-Cox log-rank test for trend, X²= 0.015, df=1, P= 0.901, X²=3.171, df=1, P= 0.995). Crown cracks were the predominant failure mode, and oblique root fractures were only observed in groups GFP and CPC. In endodontically treated incisors with a 2-mm ferrule, the post-endodontic treatment had no significant effect on fatigue survival. Non-restorable fractures only occurred in teeth restored with posts. CLINICAL SIGNIFICANCE: Although the clinical significance of laboratory studies has some limitations, this study suggests that composite buildups without posts may be an option for restoring endodontically treated incisors with 2 mm ferrule height.


Assuntos
Incisivo , Técnica para Retentor Intrarradicular , Animais , Bovinos , Resinas Compostas , Coroas , Análise do Estresse Dentário
13.
Am J Dent ; 33(5): 251-257, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33017528

RESUMO

PURPOSE: To compare the stresses generated after the use of low elastic modulus polyetheretherketone (PEEK) as dental post and crown material with glass fiber post and metal supported ceramic crowns using finite element analysis. METHODS: First an image of a maxillary central incisor taken on micro-computed tomography (micro-CT) was uploaded to a computer program. Modeling was made of all the materials in the computer environment and 3-dimensional (3D) virtual models were obtained. Using two different post materials (glass fiber and PEEK post) and two different crown materials (metal supported ceramic and PEEK crown), the modeling of the maxillary central tooth was completed and a total of four groups were obtained. Finally, 135° and 100 N forces were applied from the midpoint of the palatal surface. RESULTS: The FEA analysis showed the use of PEEK as post material decreased the stress values in the post, post cement and composite core models and did not have any significant change in the dentin and crown cement models. The use of composite veneer with PEEK substructure as crown material reduced stress values in dentin, the post and composite core and increased stress values in both the post cement and the crown cement. CLINICAL SIGNIFICANCE: Since the elastic modulus of the PEEK material is very close to dentin tissue, finite element stress analysis, less stress formation in the tooth and post core restoration compared to other post systems was observed. In this context, PEEK post may reduce irreversible complications.


Assuntos
Técnica para Retentor Intrarradicular , Coroas , Análise de Elementos Finitos , Cetonas , Polietilenoglicóis , Microtomografia por Raio-X
14.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2536-2539, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018523

RESUMO

Atherosclerosis is one of the most common vascular pathologies in the world. Among the most commonly performed endovascular treatments, percutaneous transluminal angioplasty (PTA) has been showing significantly positive clinical outcomes. Due to the complex geometries, material properties and interactions that characterize PTA procedures, finite element analyses of acute angioplasty balloon deployment are limited. In this work, finite element method (FEM) was used to simulate the inflation and deflation of a semi-compliant balloon within the 3D model of a stenosed artery with two different plaque types (lipid and calcified). Self-defined constitutive models for the balloon and the plaque were developed based on experimental and literature data respectively. Balloon deployment was simulated at three different inflation pressures (10, 12 and 14 atm) within the two plaque types. Balloon sizing influence on the arterial elastic recoil obtained immediately after PTA was then investigated. The simulated results show that calcified plaques may lead to higher elastic recoil ratios compared to lipid stenosis, when the same balloon inflation pressures are applied. Also, elastic recoil increases for higher balloon inflation pressure independent of the plaque type. These findings open the way for a data-driven assessment of angioplasty balloon sizing selection and clinical procedures optimization.Clinical Relevance- The FE model developed in this work aims at providing quantitative evaluation of recoil after balloon angioplasty. It may be useful for both manufacturers and clinicians to improve efficiency of angioplasty balloon device design and sizing selection with respect to plaque geometry and constitution, consequently enhancing clinical outcomes.


Assuntos
Angioplastia com Balão , Técnica para Retentor Intrarradicular , Angioplastia , Animais , Constrição Patológica , Análise de Elementos Finitos
15.
Medicine (Baltimore) ; 99(43): e22648, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33120754

RESUMO

To analyze the stress distribution of the maxillary central incisor with oblique fracture, repaired by different methods, using 3-dimensional finite element analysis. From the biomechanical point of view, it is expected to provide a reference for clinical selection of restoration method which is more conducive to stress distribution and preservation of dental tissue as much as possible.Use cone beam CT and finite element software to establish the finite element models of the maxillary central incisor with oblique fracture, and then create models according to 5 repairing methods(A. fiber post-core-crown group; B. cast post-core-crown group; C.3 mm deep endocrown; D.4 mm deep endocrown; E.5 mm deep endocrown)after root canal treatment, and analyze the Von Mises equivalent stress and maximum principal stress distribution and peak value of each model.When the height of dentin ferrule was fixed, the value of the Von Mises equivalent stress and the maximum principal stress in residual tooth tissue: group A was the highest, and there was no significant difference in group B, C, D and E. And the stress distribution area of 5 groups were the same. In prosthodontic layer: group B was the highest, while group A was the lowest, and the stress peak slightly increased with the increase of depth in group C, D and E. And the 5 groups were with the same stress distribution area as well. In adhesive layer: group A was the highest, while group B was the lowest, and there was little difference among group C, D and E. Group A was concentrated in 1/3 of the post tip, while group B,C,D and E were concentrated in 1/3 of the post and the post tips.Complete and high enough dentin ferrule is a requirement for repairing heavily defected maxillary central incisor with fiber post-core crown and cast post-core crown. When the dentin ferrule is incomplete, the stress distribution of the endocrown is more excellent than post-core-crown. And the endocrown with a depth of 3 mm retainer may be the best repair method. As for post-core crown restoration, the cast post-core crown is more favorable for the uniform distribution of residual tooth tissue than the fiber post-core crown.


Assuntos
Coroas , Análise do Estresse Dentário/métodos , Incisivo/fisiologia , Resinas Compostas , Dentina/fisiologia , Análise de Elementos Finitos , Humanos , Técnica para Retentor Intrarradicular , Raiz Dentária
16.
Endodoncia (Madr.) ; 38(2): 14-19, oct. 2020. ilus
Artigo em Espanhol | IBECS | ID: ibc-198455

RESUMO

INTRODUCCIÓN: Un ferrule de 2 mm a 3600 asegura la supervivencia a largo plazo del diente restaurado. Sin embargo, existen situaciones clínicas donde el ferrule es insuficiente. Existen básicamente 3 opciones de tratamiento para la obtención de ferrule sin invadir el espacio biológico: el alargamiento de corona quirúrgico, la extrusión ortodóntica rápida y la extrusión quirúrgica. CASO CLÍNICO: EL presente caso clínico describe la restauración de un premolar inferior sin ferrule por medio de la extrusión quirúrgica, el retratamiento de conductos, y la colocación de poste y corona. CONCLUSIÓN: La extrusión quirúrgica permite, de manera altamente predecible restaurar dientes sin ferrule con raíces largas y periodontalmente sanos, sin comprometer los tejidos periodontales ni necesidad de aparatología ortodóntica


INTRODUCTION: A 2-mm ferrule over 3600 ensures a long-term survival of the restored tooth. However, there are clinical situations in which ferrule is insufficient. Thus, there are 3 treatment options to obtain ferrule without invading the biological width: surgical crown lengthening, rapid orthodontic extrusion and surgical extrusion. CLINICAL CASE: The present clinical case describes the restoration of a lower premolar without ferrule by means of surgical extrusion, root canal re-treatment, and post and crown. CONCLUSION: Surgical extrusion allows predictably the restoration of long, periodontally healthy teeth with no ferrule, without compromising the periodontal tissues or the need for orthodontic appliances


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Extrusão Ortodôntica/métodos , Obturação do Canal Radicular/métodos , Aumento da Coroa Clínica/métodos , Técnica para Retentor Intrarradicular , Restauração Dentária Permanente/métodos , Resultado do Tratamento , Porcelana Dentária/uso terapêutico
17.
Braz Dent J ; 31(4): 409-416, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32901718

RESUMO

This study was conducted to evaluate whether antibacterial pretreatment irrigation with silver nanoparticles (SNPs) and silver diamine fluoride (SDF) has any effect on bond strength of fiber posts cemented with three types of resin cements in root canal space. Fifty-four endodontically treated maxillary central incisor roots were prepared for fiber post (FRC Postec Plus NO.3, Ivoclar Vivadent) cementation and divided into nine groups in terms of three cement types and two pretreatments with silver antibacterial agents. The cements were as follows: an etch-and-rinse cement (ER, Excite DSC/Variolink N), a self-etch cement (SE, ED Primer/Panavia F2.0), and a self-adhesive cement (SA, Panavia SA Luting Plus). For each cement, the control group was with no treatment and two experimental groups were with SNPs and SDF treatments that were used after acid-etching for ER cement and after EDTA treatment for SE and SA cements. After fiber post cementation, each bonded root was horizontally sectioned into 1-mm thickness microslices to create two slices for each root region (apical, middle and coronal) and underwent push-out bond strength (PBS) test. Data in MPa were analyzed with two-way ANOVA and Tukey test (p=0.05). The interaction of the pretreatment type and cement type was significant (p<0.001). SNPs and SDF significantly increased PBS with ER cement (p≤0.04). This positive effect was also marginally significant for SDF with SE cement (p=0.049). For SA cement, SNPs showed a significant positive effect, but SDF had a significant adverse effect on PBS (p<0.001). The effect of pretreatment with silver antibacterial agents prior to adhesive cementation of fiber posts depends on the resin cement used. Contrary to SNPs with beneficial or no significant effect on bonding for all cements, SDF exhibited a deleterious effect with self-adhesive cement.


Assuntos
Colagem Dentária , Nanopartículas Metálicas , Técnica para Retentor Intrarradicular , Antibacterianos , Dentina , Prata
18.
Braz Dent J ; 31(4): 417-422, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32901719

RESUMO

The aim of this study was to evaluate the effect of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) on bond strength of fiberglass posts in root canals obturated with different endodontic sealers. Seventy-eight mandibular premolars were obturated with three sealers (n=26): Endofill (END), AH Plus (AHP), and Endosequence BC Sealer (EBS). After preparation of the post space, two subgroups were formed according to the cementation of the posts (n=13): with EDC (EDC), and without EDC (control - CON). The specimens were submitted to a pull-out test, failure mode classification, and root canal surface evaluation by scanning electron microscopy after post displacement. Regarding the bond strength, a significant difference between the EDC and CON subgroups occurred only in the END (p=0.001). No difference was detected among the CON subgroups (p=0.339). However, among the EDC subgroups, AHP presented significantly higher values (END versus AHP: p=0.001; AHP versus EBS: p=0.016). Upon classification of failure modes, score 1 (≥ 50% of cement) was the most commonly observed, except for the END + EDC. Remains of endodontic sealers and resin cements were found in the cervical third, but without statistical difference (p=0.269), while in the middle third, difference occurred (p=0.004). In conclusion, EDC decreases bond strength when associated with END sealer, without changing the failure mode between the resin cement and fiberglass post. The best performance was observed when EDC was combined with AHP sealer.


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Carbodi-Imidas , Cimentação , Cimentos de Resina
19.
Indian J Dent Res ; 31(3): 475-480, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32769286

RESUMO

Objectives: To evaluate the effect of different intraradicular posts on the dimensions of computed tomography (CT) images in cone-beam and fan-beam equipment. Materials and Methods: : A total of 15 root canals of bovine teeth were instrumented up to a file #50 and root-filled by the active lateral condensation technique. The teeth were randomly divided into three groups, according to the type of intraradicular post: 1) tight fiberglass post; 2) anatomical fiberglass post; and 3) metal post. The root canals were desobturated in 10 mm and tomographic images were acquired in two devices, a cone-beam and fan-beam equipment. Then, the intraradicular posts were cemented using an automix self-conditioning and self-adhesive resin cement, and the final acquisitions of the CT images were performed for analysis. The diameter of the canal was compared before and after cementation of the intraradicular posts. The t-test was used between the initial and final measurements of each tomograph and also between the cone-beam and fan-beam tomographs (α = 0.05). Results: The anatomical fiberglass post presented the smallest dimensional change among the initial and final measurements, followed by the tight fiberglass post, with the metal post being the material that showed the most considerable dimensional difference in the cone-beam. Conclusion: All of the intraradicular posts used promoted a change in the size of the CT image. The fan-beam scanner promoted greater dimensional change in the images.


Assuntos
Técnica para Retentor Intrarradicular , Animais , Bovinos , Cimentação , Tomografia Computadorizada de Feixe Cônico , Cavidade Pulpar , Cimentos de Resina , Tratamento do Canal Radicular
20.
J Hist Dent ; 68(2): 71-86, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32852269

RESUMO

For decades the dismantling of previous dental work to correct inferior root canal procedures or to address recurrent dental caries has provided a significant amount of work for the restorative dentist. When coupled with teeth that have been root treated and also have an intraradicular post or dowel, the clinician was often presented with the challenge of post removal, without fracturing the root, and revision (retreatment) of the root canal procedures. While today's contemporary dentistry has the wherewithal to use ultrasonic devices to loosen and remove the post, this was not always the case historically, and creativity in this process was the hallmark of many of our predecessors.


Assuntos
Técnica para Retentor Intrarradicular , Cárie Dentária , Humanos , Retratamento , Tratamento do Canal Radicular , Ultrassom
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