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1.
J Prosthodont ; 2020 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-33219727

RESUMEN

PURPOSE: To evaluate the fracture resistance and failure modes of endodontically treated mandibular molars restored with different designs of inlays, onlays and endocrowns. MATERIALS AND METHODS: Extracted mandibular third molars (n = 180) were used. An access cavity was prepared on the occlusal surface of each tooth and the roots were obturated with gutta percha. All specimens were randomly divided into 6 groups (n = 30/group) according to the cavity design and the restoration material used. C: control group without access cavity preparation. IE: MOD inlay preparation with EverX Posterior (GC Europe) in the pulp chamber. IG: MOD inlay preparation with G-aenial Universal Flo (GC America) in the pulp chamber. OE: onlay preparation with EverX Posterior (GC Europe) in the pulp chamber. OG: onlay preparation with G-aenial Universal Flo (GC America) in the pulp chamber. EC: endocrown with an empty pulp chamber. All restorations were fabricated with CAD/CAM system using CERASMART® (GC Dental products Europe, Belgium) CAD/CAM blocks. Specimens were thermal-cycled and were subjected to a compressive load applied at 30° angle relative to the long axis of the tooth with a universal testing machine. Results were statistically analyzed by ANOVA followed by Tukey post hoc tests. Chi-square test and Fisher Exact tests were used for the comparisons among groups. RESULTS: The mean fracture strength was significantly different between the groups (P<.001); it was significantly highest for intact teeth, followed by endocrowns (P = .021). The strength was significantly lower for inlays (with G-aenial Universal Flo and EverX Posterior), intermediate for onlays with EverX Posterior followed by onlays with G-aenial Universal Flo. CONCLUSIONS: Endocrowns exhibited higher fracture resistance than other tested composite resin groups. Endocrowns and onlays showed a more favorable failure mode than inlay restorations. This article is protected by copyright. All rights reserved.

2.
Materials (Basel) ; 13(19)2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-33019681

RESUMEN

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S. mutans and L. acidophilus, as well as antifungal effect on C. albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S. mutans and L. acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S. mutans. All tested EOs exhibited antifungal activity against C. albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S. mutans and C. albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L. acidophilus.

3.
Int J Comput Dent ; 23(3): 225-233, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32789310

RESUMEN

AIM: To evaluate the fracture resistance and failure pattern of 3D-printed and milled composite resin crowns as a function of different material thicknesses. MATERIALS AND METHODS: Three typodont tooth models were prepared to receive a full coverage composite resin crown with different thicknesses (0.5, 1.0, and 1.5 mm). The prepared master casts were digitally scanned using an intraoral scanner, and the STL files were used to fabricate 60 nanocomposite crowns divided into two groups according to the material thickness (n = 10) and fabrication method: a 3D-printed group (3D) using an SLA printer with nanocomposite, and a milled group (M) using a milling machine and composite blocks. All crowns were adhesively seated on stereolithography (SLA)-fabricated dies. All samples were subjected to thermomechanical loading and fracture testing. The load to fracture [N] was recorded and the failure pattern evaluated. Data were statistically analyzed using a two-way ANOVA followed by a Bonferroni post hoc test. The level of significance was set at α = 0.05. RESULTS: The 3D group showed the highest values for fracture resistance compared with the milled group within the three tested thicknesses (P < 0.001). The 3D and M groups presented significantly higher load to fracture for the 1.5-mm thickness (2383.5 ± 188.58 N and 1284.7 ± 77.62 N, respectively) compared with the 1.0-mm thickness (1945.9 ± 65.32 N and 932.1 ± 41.29 N, respectively) and the 0.5-mm thickness, which showed the lowest values in both groups (1345.0 ± 101.15 N and 519.3 ± 32.96 N, respectively). A higher incidence of irreparable fractures was observed for the 1.5-mm thickness. CONCLUSION: 3D-printed composite resin crowns showed high fracture resistance at different material thicknesses and can be suggested as a viable solution in conservative dentistry.


Asunto(s)
Porcelana Dental , Fracaso de la Restauración Dental , Cerámica , Diseño Asistido por Computadora , Coronas , Diseño de Prótesis Dental , Análisis del Estrés Dental , Humanos , Ensayo de Materiales , Impresión Tridimensional
4.
Materials (Basel) ; 13(12)2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-32549198

RESUMEN

This in vitro study aims to evaluate whether a solution of 10% sodium ascorbate (SA) may exert a beneficial effect on the bonding of composite to enamel after using different bleaching agents and protocols. Microtensile bond strength (µTBS) was evaluated on 72 freshly extracted human central incisors, divided into eight experimental groups and one control group (total n = 9): Group 1 serves as control (nonbleached). Group 2 was bleached with 5% carbamide peroxide. Group 3 was bleached with 5% carbamide peroxide and then treated with 10% SA. Group 4 was bleached with 10% carbamide peroxide. Group 5 was bleached with 10% carbamide peroxide, then treated with 10% SA. Group 6 was bleached with 16% carbamide peroxide. Group 7 was bleached with 16% carbamide peroxide, then treated with 10% SA. Group 8 was bleached with 6% hydrogen peroxide. Group 9 was bleached with 6% hydrogen peroxide, then treated with 10% SA. All groups were restored immediately after the different treatments using a resin composite. The µTBS values were measured using a universal testing machine and statistical analysis was performed by means of normality and variance analyses, SIDAK test for univariate test and multiple comparisons, and Student test to compare µTBS values of each group with the control. The mean µTBS values in groups 2, 4, 6, 8 were significantly lower than controls. For groups 3, 5, 7, 9, subjected to antioxidant (10% SA) application, all µTBS values increased significantly. However, only for Groups 3 and 5 there was no significant difference with the control. Applying 10% SA for 10 min may improve the bond strength composite/bleached enamel just when whitening is performed with 5% and 10% carbamide peroxide.

5.
Quintessence Int ; 51(6): 510-518, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32424377

RESUMEN

Digital photography has already established its irrefutable importance in today's world. It is becoming an indispensable tool in various fields. In dentistry specifically, photography can be employed in several ways that can be beneficial to the patient and the dental community. It allows a simple and clear depiction of an otherwise abstract concept, but high-quality pictures are always required. The evolution of mobile cameras has made an enormous impact on digital photography and its accessibility: high-quality pictures can now be easily taken. This article explains the assets of smartphone cameras' evolution and how it led to the conception of Smile Lite Mobile Dental Photography. Applications of dental photography are presented, such as documentation and communication with the laboratory technician and the patient. Mobile dental photography is not confined to dentistry but can also be used for artistic purposes. (Quintessence Int 2020;51:510-518; doi: 10.3290/j.qi.a44365; Originally published (in German) in Quintessenz Zahnmedizin 2019(12);70:1408-1417).


Asunto(s)
Documentación , Fotografía Dental , Comunicación , Humanos , Fotograbar , Sonrisa
6.
J Contemp Dent Pract ; 20(9): 1014-1018, 2019 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-31797821

RESUMEN

AIM OF STUDY: Evaluation of the bond strength of the resin cement after enamel conditioning with erbium-doped yttrium aluminum garnet laser compared to other four different techniques. MATERIALS AND METHODS: The study consisted of 50 enamel specimens excluded from the smooth surfaces of newly extracted human 3rd molars. The specimens were randomly divided into five groups in terms of the enamel treatment technique. Each group (n = 10) was conditioned differently by bevel and acid etching group (I), acid etching technique group (II), double acid etching technique group (III), air abrasion followed by acid etching group (IV), and Er:YAG laser followed by acid etching group (V). After enamel treatment, a resin cylinder was installed using split Teflon matrix on each enamel specimen. Then the specimens were exposed to a shear strength device, and shear force was applied. The results were recorded with Newton. The required data were collected and statistically analyzed. A one-way ANOVA test was conducted to compare the five study groups using SPSS version 21 (p < 0.05). RESULTS: All groups showed high shear bond strength values ranging from 19.26 MPa (for group III) to 27.05 MPa (for group V). The enamel treatment with Er:YAG laser followed by acid etching gave the best results with significant differences compared to the other groups. CONCLUSION: Within the limitations of the present study, it can be concluded that the combination between the Er:YAG laser and the acid etching enhances the bond strength of resin cement with the enamel. CLINICAL SIGNIFICANCE: The use of Er:YAG laser followed by acid etching can be a successful technique for enamel conditioning and the results showed their superiority over the other groups.


Asunto(s)
Recubrimiento Dental Adhesivo , Láseres de Estado Sólido , Grabado Ácido Dental , Esmalte Dental , Humanos , Cementos de Resina , Resistencia al Corte
7.
J Orofac Orthop ; 69(5): 383-92, 2008 Sep.
Artículo en Inglés, Alemán | MEDLINE | ID: mdl-19238890

RESUMEN

OBJECTIVE: The purpose of this study was to evaluate the shear bond strength of orthodontic bracket when bonded to pre-conditioned and intact enamel using a self-etching primer within 6 hours and after thermal cycling. MATERIAL AND METHODS: One hundred and twenty freshly-extracted human teeth were divided into four groups according to how the buccal surface to be bonded had been pre-conditioned: 1) acid-etched with 37% phosphoric acid, 2) sand-blasted with 50 microns aluminum-oxide, 3) matted with diamond burr, and 4) intact enamel used as control. Orthodontic metal brackets were bonded to the teeth using the same composite resin (Transbond XT) and self-etching primer (Transbond Plus Self-Etching Primer). Brackets were debonded within 6 hours or after thermal cycling for 2500 times (5 degrees C--37 degrees C--55 degrees C). Shear bond strength was measured on a testing machine at a crosshead speed of 3 mm/min. The bracket-failure interface was quantified according to the modified adhesive remnant index score (ARI). Data were analyzed using the two-way ANOVA test, Scheffé confidence interval of differences of means, and the chi-square test (p < 0.05). RESULTS: All the pre-conditioned groups showed significantly higher shear bond strength before and after thermal cycling than the control group. There was no significant correlation between thermal cycling and shear bond strength. The ARI scores revealed that the bond failed primarily on the adhesive-enamel interface in all groups before and after thermal cycling, with the exception of the acid-etched group, whose bonds failed mainly on the adhesive-bracket interface after thermal cycling. CONCLUSION: The authors recommend that the enamel be preconditioned before applying the self-etching primer when greater shear bond strength is desired.


Asunto(s)
Recubrimiento Dental Adhesivo/métodos , Soportes Ortodóncicos , Grabado Ácido Dental/métodos , Humanos , Técnicas In Vitro , Cementos de Resina , Resistencia al Corte
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