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1.
Int J Prosthodont ; 34(1): 61-69, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33570521

RESUMEN

PURPOSE: To compare the marginal and internal gap values of different types of ceramic crowns fabricated based on digital and conventional impression methods. MATERIALS AND METHODS: Ten noncarious extracted human teeth were prepared, and 60 restorations were made using six different impression and fabrication methods. Silicone replicas were obtained for marginal and internal gap evaluation. Statistical analyses were performed using Mann-Whitney U and Kruskal-Wallis tests (P < .05). RESULTS: Statistically significant differences were found among various impression and fabrication methods. The smallest gap value was shown by the monolithic zirconia indirect digital scanning group (31.13 µm), and the largest for the lithium disilicate indirect digital scanning group (90.09 µm). CONCLUSION: The marginal and internal gap values of the restorations in the present study were 31.13 to 90.09 µm. The marginal and internal discrepancies of the tested materials were considered clinically acceptable.


Asunto(s)
Técnica de Impresión Dental , Adaptación Marginal Dental , Diseño Asistido por Computadora , Coronas , Porcelana Dental , Diseño de Prótesis Dental , Humanos
2.
J Adhes Dent ; 23(1): 37-46, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33512114

RESUMEN

PURPOSE: To assess possible correlations between clinical outcomes and SEM marginal analysis in a prospective long-term clinical study using two adhesives in incisors and canines. Materials and Methods: Thirty-five patients received class III and IV restorations with two different adhesives, either the one-step self-etch adhesive iBond Gluma inside (1-SE) or the two-step etch-and-rinse adhesive Gluma Comfort Bond (2-ER) combined with the fine particle hybrid composite Venus. The restorations were clinically evaluated (modified USPHS criteria) over 90 months. Based on resin replicas, a quantitative marginal SEM analysis was performed using the criteria "gap", "perfect margin", "overhang", and "underfilled". The results of the quantitative marginal analysis were statistically compared and related to clinical evaluations. The SEM data were analyzed statistically using the Kolmogorov-Smirnov test, Wilcoxon test, and mixed models test. Results: Of the 35 subjects at baseline, 16 (1-SE) and 17 (2-ER) were clinically re-examined after 90 months. 13 patients were included in the SEM analysis due to uninterrupted documentation over 90 months or until restoration loss. SEM analysis showed larger discriminative power between groups than did the clinical examination, but the trend was the same. Marginal analysis ("gap", "perfect margin") showed significant differences between the materials after 12 months, which clinically began to show a trend from 12 months, and were statistically verified after 48 and 90 months. "Overhang" and "underfilled" did not reveal significant differences between the systems or over time. Conclusion: SEM marginal analysis using the replication technique is a powerful tool to reveal differences between adhesives. Compared to clinical evaluation, group differences can be detected earlier, with both outcome parameters confirming each other over long observation periods.


Asunto(s)
Resinas Compuestas , Restauración Dental Permanente , Análisis Costo-Beneficio , Cementos Dentales , Adaptación Marginal Dental , Recubrimientos Dentinarios , Humanos , Estudios Prospectivos , Cementos de Resina
3.
J Adhes Dent ; 23(1): 21-34, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33512113

RESUMEN

The importance of the interdental anatomy of a class-2 direct composite restoration is one of the most underestimated topics in direct posterior composite restorations. The proximal emergence profile of the restoration and the contact area should be designed to maximize arch continuity and to minimize food impaction. Other restorative criteria that must be fulfilled are marginal adaptation compatible with the dental and periodontal integrity, and geometry of the marginal ridge compatible with the mechanical integrity of the restoration under load. Shortcomings will result in masticatory discomfort, caries, periodontal problems and undesired movement of teeth. In vitro and in vivo studies showed that the use a contoured sectional metal matrix band with a separation clamp results in the tightest contact point. However, this matrix system also has shortcomings and does not give the expected result in all class-2 cavities. The variation in depth, width of the box, distance between the cervical cavity margin and the adjacent tooth requires customization of the interproximal space. In order to realize this, sectional matrix bands with several profiles of curvature, variation of wedges and separation clamps, and the use of teflon tape are required. In addition, dentists should follow a protocol allowing them to build a proximal composite surface that fulfills the required restorative criteria. Pre-wedging, space evaluation, interproximal clearance, correct selection, positioning and stabilization of the matrix band are important steps in this protocol.


Asunto(s)
Resinas Compuestas , Restauración Dental Permanente , Preparación de la Cavidad Dental , Adaptación Marginal Dental , Bandas de Matriz
4.
Braz. dent. sci ; 24(1): 1-8, 2021. tab, ilus
Artículo en Inglés | LILACS, BBO - Odontología | ID: biblio-1145442

RESUMEN

Objetivo: Estudos demostraram que a zircônia monolítica um dos materiais restauradores desenvolvidos recentemente, resolveu vários problemas de restauração de zircônia. Portanto, a precisão marginal e o ajuste interno são necessários para o sucesso clinico e para a qualidade da restauração, e o espaço do cimento pode influenciar o ajuste marginal. Assim, o presente estudo teve como objetivo investigar os efeitos da espessura do cimento e o tipo de restauração na discrepância marginal. Material e métodos: foram usadas para fabricação de coroa total. Dois tipos de materiais incluindo Zirconia monolítica (Zolid) e Sintron foram usadas para produzir a coroa total. As amostras de cada grupo foram digitalizadas em laboratório dentário por um scanner 3D, projetadas e acessadas usando CAD-CAM. As amostras foram divididas em quatro grupos de cinco com espaço de 30 e 50 mícrons de cimento. Para avaliar a discrepância marginal, as coroas foram colocadas em seus respectivos dentes sem o uso de qualquer intermediário e examinados em micro-CT. Os dados foram avaliados pelo software SPSS. Resultados: Descobriu-se que a discrepância marginal do Sintron é maior que a discrepância da zircônia monolítica. Na verdade, a zircônia monolítica com espaço de 50 µm de cimento exibiu uma menor discrepância marginal, e o espaço de cimento do Sintron não influenciou significantemente na discrepância marginal. Conclusão: Concluiu-se que os tipos de material e o espaço do cimento influencia na discrepância marginal da restauração construída pelo fluxo digital (AU)


Objective: Studies demonstrated that as one of then ewly developed restorative materials, monolithic zirconia resolved several issues of zirconia restoration. Therefore, marginal accuracy and internal fit are necessary for clinical success and quality of restorations, and cement space may influence the marginal fit. Thus, the present research aimed to investigate the effects of the cement thickness and kind of restoration on the marginal discrepancy. Material and methods: In this study, 20 maxillary left first molars, prepared by DRSK Co., were used to fabricate a full crown. Two types of material included monolithic zirconia (Zolid) and Sintron were used to make a full crown. Samples from each group were scanned by dental laboratory 3D scanner and designed and processed using CAD-CAM. The samples were divided into four groups of five with 30-and 50- µm cement spaces. In order to assess the vertical marginal discrepancy, the crowns were fittedon their respective teeth without using any mediator and examined by a micro-CT scanner. Data were analyzed by SPSS software. Results: It has been found that marginal discrepancy in Sintron is higher than the discrepancy of monolithic zirconia. In fact, monolithic zirconia with 50-micron cement space exhibited the least marginal discrepancy and the cement space in Sintron did not significantly influence the marginal discrepancy. Conclusion: It has been concluded that the material kinds and cement space influence the restoration marginal discrepancy constructed by digital workflow (AU)


Asunto(s)
Adaptación Marginal Dental , Cementos Dentales , Microtomografía por Rayos X
5.
Oper Dent ; 45(5): E255-E270, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-33170938

RESUMEN

CLINICAL RELEVANCE: Non-carious cervical lesion restorations using a dual-cure universal adhesive in self-etch and etch-and-rinse mode showed satisfactory clinical performance after 18 months. SUMMARY: Objectives: The objective of this multicenter, double-blind, split-mouth randomized clinical trial was to evaluate the clinical performance of a new dual-cure universal adhesive system (Futurabond U, Voco GmBH) when applied using different strategies over a period of 18 months.Methods and Materials: Fifty patients participated in this study. Two hundred non-carious cervical lesions were restored using the adhesive Futurabond U according to four adhesive strategies (n=50 per group): only self-etch (SEE), selective enamel etching + self-etch (SET), etch-and-rinse with dry dentin (ERDry), and etch-and-rinse with wet dentin (ERWet). After the adhesive application, cavities were restored using Admira Fusion composite resin. These restorations were evaluated according to FDI World Dental Federation criteria for the following characteristics: retention/fracture, marginal adaptation, marginal staining, postoperative sensitivity, and caries recurrence.Results: After 18 months, only four patients (12 months: one patient, n=4 restorations; and 18 months: three patients, n=12 restorations) were not evaluated. Fourteen restorations were lost after 18 months of clinical evaluation (four for SEE, three for SET, three for ERDry, and four for ERWet). The retention rates for 18 months (95% confidence interval) were 92% (81%-97%) for SEE, 94% (83%-97%) for SET, 94% (83%-97%) for ERDry, and 92% (81%-97%) for ERWet (p>0.05). Thirty-eight restorations were considered to have minor discrepancies in marginal adaptation at the 18-month recall (13 for SEE, 13 for SET, six for ERDry, and six for ERWet; p>0.05). Fourteen restorations were detected as a minor marginal discoloration at the 18-month recall (six for SEE, six for SET, one for ERDry, and one for ERWet; p>0.05). However, all were considered clinically acceptable. No restorations showed postoperative sensitivity or caries recurrence at the time.Conclusion: The clinical performance of the Futurabond U did not depend on the bonding strategy used, and it was considered reliable after 18 months of clinical evaluation, although more marginal discrepancy was observed in the self-etch group.


Asunto(s)
Recubrimiento Dental Adhesivo , Caries Dental , Resinas Compuestas , Caries Dental/terapia , Cementos Dentales , Adaptación Marginal Dental , Restauración Dental Permanente , Recubrimientos Dentinarios , Humanos , Cementos de Resina , Cuello del Diente
6.
Niger J Clin Pract ; 23(9): 1274-1280, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32913168

RESUMEN

Background: Poor marginal adaptation may give rise to a series of biological complications. Despite its importance, comparative studies on marginal adaptation of metal-ceramic fixed restorations fabricated with newer methods are limited. Aim: Therefore, it was aimed to assess the marginal accuracy of copings fabricated with subtractive and additive manners used in contemporary dentistry. Materials and Methods: For a typodont model, 60 three-unit cobalt-chrome metal copings were fabricated by selective laser sintering (SLS), hard alloy milling (HAM), and soft alloy milling (SAM) in comparison to casting (C). Marginal discrepancy assessment was performed by using replication technique. Mesiodistal and buccopalatal cross-sections of silicone replicas were investigated under a stereomicroscope at × 80 magnification. A total of 960 measurements were subsequently made by means of corresponding image-review software on captured images after calibration of the software to µm scale. Obtained data were subjected to nonparametric Kruskal Wallis and Tamhane post-hoc tests (α =0.05). Results: Marginal adaptation of C group was significantly inferior to test groups in both canine- and premolar-teeth measurements (P < 0.05). Marginal fit was found to be tooth dependent (P < 0.001). HAM, SAM, and SLS groups exhibited analogous marginal discrepancy values on canine-tooth measurements. Differences among these groups were not statistically significant (P > 0.05). SAM and SLS groups demonstrated better marginal adaptation than others on premolar-tooth measurements. Also, no statistically significant difference was detected between SAM and SLS groups (P > 0.05). Conclusions: SAM group demonstrated superior marginal accuracy. All groups had clinically acceptable marginal discrepancy values (<120 µm), except cast group.


Asunto(s)
Aleaciones de Cromo/química , Diseño Asistido por Computadora , Técnica de Colado Dental , Adaptación Marginal Dental , Aleaciones de Cerámica y Metal/química , Adaptación Psicológica , Calor , Humanos , Rayos Láser
7.
Am J Dent ; 33(4): 201-205, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32794395

RESUMEN

PURPOSE: To evaluate the effect of bacterial exposure on the marginal integrity of dentin-resin interfaces for composites with and without bioactive glass (BAG). METHODS: Cavity preparations of 5 mm width and 1.5 mm depth were machined into dentin disks by means of a computer controlled milling system. After applying the bonding agent, cavity preparations (n=3-5) were restored by incremental technique with experimental resin composites (50:50 BisGMA/TEGDMA: 72wt% filler) with different filler compositions: control - 67 wt% silanated strontium glass and 5wt% aerosol-silica filler and BAG - 57 wt% silanated strontium glass and 15 wt% BAG-65 wt% silica. Samples were then stored in sterile Todd-Hewitt media or co-incubated with Streptococcus mutans (UA 159), at 37°C, 5% CO2 for 1-2 weeks. For samples co-incubated with a living biofilm, a luciferase assay was performed in order to assess its viability. Surfaces were impressed before and after each storage condition and replicas examined in a scanning electron microscope. Using image analysis software (Image J), the discontinuous margins percentage (%DM) was quantitatively assessed. Data were analyzed using two-way ANOVA followed by Tukey's test (α= 0.05). RESULTS: Gap size ranged between 7-23 µm. The bacterial exposure significantly increased the %DM in both groups predominantly due to the formation of new gap regions. There was no difference between control and BAG composites regarding %DM and the biofilm viability. Bacterial exposure promoted degradation of composite restoration marginal integrity, with no difference between composites with and without BAG. CLINICAL SIGNIFICANCE: The samples incubated with living biofilm had a higher gap percentage in the margins, confirming the negative effect of cariogenic bacteria on margin degradation. The parameters defined for such synergy can help to understand the multi-factorial aspect of marginal discontinuity and therefore, predict the behavior of composite restorations subjected to the challenging oral environment.


Asunto(s)
Resinas Compuestas , Preparación de la Cavidad Dental , Biopelículas , Adaptación Marginal Dental , Restauración Dental Permanente , Vidrio , Microscopía Electrónica de Rastreo , Streptococcus mutans
8.
Am J Dent ; 33(4): 206-212, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32794396

RESUMEN

PURPOSE: This double-blind, randomized clinical trial evaluated the influence of dentin moisture on postoperative sensitivity (POS) in posterior restorations using a simplified etch-and-rinse adhesive, until 12 months of clinical service. METHODS: 90 restorations were inserted in 45 patients to treat carious lesions or to replace existing posterior restorations with a depth ≥ 3 mm. After cavity preparation, the simplified etch-and-rinse adhesive (Adper Single Bond 2) was applied on dry or wet dentin followed by a bulk-fill resin composite (Filtek Bulk Fill) under rubber dam isolation. The patient's spontaneous and stimulated POS was evaluated at baseline and after 7 days, 6 months, and 12 months of clinical evaluation. The secondary parameters (marginal discoloration, marginal adaptation, fracture and recurrence of caries) were evaluated by World Dental Federation (FDI) criteria after 7 days, 6 and 12 months of clinical evaluation. RESULTS: No significant spontaneous and stimulated POS was observed when dry and wet dentin were compared (P> 0.05). A significant and higher risk of spontaneous POS (18.6%; 95% CI 9.7 to 32.6) occurred up to 48 hours after restoration placement for both groups when compared to all evaluation times (P< 0.03). However, the intensity of POS was mild at up to 48 hours with a difference between the dry and wet dentin groups (P> 0.79). When secondary parameters were evaluated, no significant difference between the groups were observed (P> 0.05). CLINICAL SIGNIFICANCE: The moisture level of the dentin substrate in posterior restorations does not influence POS in bulk-fill resin composite posterior restorations when associated with an etch-and-rinse ethanol-based adhesive system.


Asunto(s)
Caries Dental , Sensibilidad de la Dentina , Resinas Compuestas , Adaptación Marginal Dental , Restauración Dental Permanente , Dentina , Recubrimientos Dentinarios , Método Doble Ciego , Humanos , Cementos de Resina
9.
J Esthet Restor Dent ; 32(7): 691-698, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32757232

RESUMEN

OBJECTIVES: To compare the clinical performance of a universal adhesive in class V non-carious cervical lesions (NCCLs) using two surface treatment protocols (self-etch [SfE] vs selective-enamel-etch [SelE]). MATERIAL AND METHODS: Thirty-three adults, each with ≥2 NCCLs, received one resin composite restoration utilizing a SfE universal adhesive and another utilizing the adhesive and SelE with 37% phosphoric acid. Restorations were evaluated for sensitivity, retention, marginal discoloration, marginal adaptation, and clinical acceptability through 24 months using Cochran-Mantel-Haenszel tests for stratified, ordered categorical outcomes. RESULTS: Sixty-six restorations (35 SfE, 31 SelE; 27 volunteers) were evaluated at 24 months. There were no significant differences between SfE and SelE for sensitivity, retention, marginal adaptation, or clinical acceptability. One SfE restoration was lost. Marginal adaptation was significantly worse at 24 months than baseline for SelE (P = 0.01), but not for SfE. Marginal discoloration was significantly worse for SfE (P = 0.02), but not for SelE. Sensitivity improved from baseline to 24 months for both groups (SelE P = 0.004, SfE P = 0.002). CONCLUSIONS: Twenty-four-month data indicated significantly reduced sensitivity for both groups, worse marginal discoloration for SfE, and worse marginal adaptation for SelE. No changes in retention or clinical acceptability were observed in either group. All retained restorations were clinically acceptable at 24 months. CLINICAL SIGNIFICANCE: Both self-etch and selective enamel etch techniques with a universal adhesive produced clinically acceptable results in resin composite restorations for NCCLs over 2 years.


Asunto(s)
Restauración Dental Permanente , Cuello del Diente , Adulto , Resinas Compuestas , Cementos Dentales , Adaptación Marginal Dental , Recubrimientos Dentinarios , Humanos , Cementos de Resina
10.
BMC Oral Health ; 20(1): 189, 2020 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-32631333

RESUMEN

BACKGROUND: Chairside systems are becoming more popular for fabricating full-ceramic single restorations, but there is very little knowledge about the effect of the entire workflow process on restoration fit. Therefore, this study aimed to compare the absolute marginal discrepancy (AMD) and the full internal fit (FULL) of all-ceramic crowns made by two chairside systems, Planmeca FIT and CEREC, with detailed and standard mill settings. METHODS: One upper molar was prepared for an all-ceramic crown in human cadaver maxilla. Full-arch scans were made by Emerald or Omnicam four times each. Twenty-four e.max crowns were designed and milled by the Planmill 30s or 40s or CEREC MCXL mills with either detailed or standard settings. The cadaver tooth was extracted, and each crown was fixed on it and scanned by a high-resolution microCT scanner. The AMD and FULL were measured digitally in mesio-distal and bucco-lingual 2D slices. The actual and predicted times of the milling were also registered. RESULTS: No differences were observed between detailed or standard settings in either system. The AMD was significantly higher with CEREC (132 ± 12 µm) than with either Planmill 30s (71 ± 6.9 µm) or 40s (78 ± 7.7 µm). In standard mode, the FULL was significantly higher with CEREC (224 ± 9.6 µm) than with either Planmill 30s (169 ± 8.1 µm) or 40s (178 ± 8.5 µm). There was no difference between actual and predicted time with the two Planmeca models, but with CEREC, the actual time was significantly higher than the predicted time. The 30s had significantly higher actual and predicted times compared to all other models. Across all models, the average milling time was 7.2 min less in standard mode than in detailed mode. CONCLUSIONS: All fit parameters were in an acceptable range. No differences in fit between Planmeca models suggest no effect of spindle number on accuracy. The detailed setting has no improvement in the marginal or internal fit of the restoration, yet it increases milling time.


Asunto(s)
Cerámica , Diseño Asistido por Computadora , Coronas , Adaptación Marginal Dental , Diseño de Prótesis Dental , Cadáver , Técnica de Impresión Dental/instrumentación , Humanos
11.
J Prosthet Dent ; 124(3): 350.e1-350.e11, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32665119

RESUMEN

STATEMENT OF PROBLEM: Digital methods have been increasingly used to evaluate the fit of prostheses, but the accuracy of digital methodology has not been fully clarified. PURPOSE: The purpose of this systematic review and meta-analysis was to assess the reliability of digital measurement methods for evaluating the marginal fit of fixed dental prostheses (FDPs) and to identify the potential factors that can influence the accuracy of the measurement methods. MATERIAL AND METHODS: The differences between digital and conventional measurement methods were analyzed by searching PubMed, Scopus, Web of Science, and Google Scholar databases for studies reporting the marginal fit of FDPs. The agreement of data collection among the reviewers was confirmed by the Cohen kappa coefficient, and the MINORS scale was used to rate the quality of the included studies. The heterogeneity among the studies was evaluated, and meta-analyses with global and subgroup analyses were performed. RESULTS: Ten in vitro studies were selected according to the eligibility criteria with substantial interreader concordance (κ=0.88). The standard mean difference of the meta-analysis for marginal discrepancy was 0.12 µm (95% confidence interval: -0.12 to 0.35), indicating that no statistically significant differences were found in the marginal discrepancies observed with digital and conventional methods (P=.343). The subgroup analysis for alloy-based prostheses was not significantly different, nor between the material and measurement methods (P=.060). CONCLUSIONS: Digital methods appear to be reliable as an alternative to conventional methods for evaluating the marginal fit of FDPs. To confirm the results of this study and to identify the influencing factors on the accuracy of digital measurement methods, further controlled laboratory and clinical studies are needed.


Asunto(s)
Implantes Dentales , Adaptación Marginal Dental , Diseño Asistido por Computadora , Diseño de Prótesis Dental , Reproducibilidad de los Resultados
12.
J Adhes Dent ; 22(4): 343-351, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32666060

RESUMEN

PURPOSE: This randomized, split-mouth clinical study evaluated the marginal quality of direct class-I and class-II restorations made of microhybrid composite that were applied using two polymerization protocols and two marginal evaluation criteria. MATERIALS AND METHODS: A total of 50 patients (mean age: 33 years) received 100 direct class-I or class-II restorations in premolars or molars. Three calibrated operators made the restorations. After conditioning the tooth with 2-step etch-and-rinse adhesive, restorations were made incrementally using microhybrid composite. Each layer was polymerized using a polymerization device operated either in regular mode (600-650 mW/cm2 for 20 s) (RM) or high-power (1200-1300 mW/cm2 for 10 s) mode (HPM). Two independent, calibrated operators evaluated the restorations 1 week (baseline) and 6 months after restoration placement, and thereafter annually up to 10 years using modified USPHS and SQUACE criteria. Data were analyzed using the Mann-Whitney U-test (α = 0.05). RESULTS: Alpha scores (USPHS) for marginal adaptation (76% and 74% for RM and HPM, respectively) and marginal discoloration (70% and 72%, for RM and HPM, respectively) did not show significant differences between the two polymerization protocols (p > 0.05). Alpha scores (SQUACE) for marginal adaptation (78% and 74% for RM and HPM, respectively) and marginal discoloration (70% for both RM and HPM) were also not significantly different at the 10-year year follow-up (p > 0.05). CONCLUSION: Regular and high-power polymerization protocols had no influence on the stability of marginal quality of the microhybrid composite tested up to 10 years. Both modified USPHS and SQUACE criteria confirmed that regardless of the polymerization mode, marginal quality of the restorations deteriorated significantly compared to baseline (p < 0.05).


Asunto(s)
Resinas Compuestas , Adaptación Marginal Dental , Restauración Dental Permanente , Adulto , Diente Premolar , Estudios de Seguimiento , Humanos , Polimerizacion , Estados Unidos , United States Public Health Service
13.
J Prosthet Dent ; 124(5): 565.e1-565.e7, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32636071

RESUMEN

STATEMENT OF PROBLEM: Demand is increasing for polyetheretherketone (PEEK) as a fixed dental prosthesis core material. However, information is lacking about how the precision of these restorations is affected by the fabrication procedures. PURPOSE: The purpose of this in vitro study was to evaluate the influence of different fabrication techniques on the marginal precision of PEEK single-crown copings. MATERIAL AND METHODS: A stainless-steel master die was designed to simulate a prepared mandibular second molar to receive ceramic crowns. Thirty PEEK copings were fabricated and divided into 3 groups (n=10) according to the fabrication technique: milled from a prefabricated PEEK blank by using a computer-aided design and computer-aided manufacturing (CAD-CAM) system (PC); pressed from prefabricated PEEK pellets (PP); and pressed from PEEK granules (PG); in addition, 3-mol yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) copings (n=10) were produced by using the same CAD-CAM system and served as a control. Marginal precision measurements (in µm) were recorded at 4 reference points on each coping by using a digital microscope. The data obtained were statistically analyzed by using 1-way ANOVA and the pair-wise Tukey (HSD) test to study the difference between group mean values (α=.05). RESULTS: The overall mean ±standard deviation marginal gap at the marginal opening for the copings was 78 ±10 µm for PEEK granules copings, 72 ±9 µm for PEEK pellet copings, 45 ±6 µm for PEEK CAD-CAM copings, and 43 ±1 µm for the 3Y-TZP CAD-CAM control. A statistically significant difference was found between the milled and pressed copings as indicated by the ANOVA test (P<.001). The pair-wise Tukey honestly significant difference (HSD) test showed a nonsignificant difference (P>.05) between milled 3Y-TZP and milled PEEK copings; moreover, no significant difference was observed between the PEEK copings pressed from pellets or granules (P>.05). CONCLUSIONS: The marginal precision of PEEK CAD-CAM-fabricated copings showed significantly lower mean marginal gap values than PEEK pressed copings. The marginal gap mean values recorded were all within a clinically acceptable range (120 µm).


Asunto(s)
Adaptación Marginal Dental , Diseño de Prótesis Dental , Adaptación Psicológica , Diseño Asistido por Computadora , Coronas , Cetonas , Polietilenglicoles , Circonio
14.
Dent Med Probl ; 57(2): 185-190, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32609957

RESUMEN

BACKGROUND: Marginal fit is the most important criterion in the evaluation of the clinical acceptability of fixed restorations. Due to cement solubility and plaque retention, marginal gaps are potentially harmful to both the teeth and the periodontal tissues. OBJECTIVES: The aim of the study was to investigate the accuracy of the fit of dental metal-ceramic bridges manufactured with the use of direct metal laser sintering (DMLS), and to explore the effects of porcelain firing on the marginal, axial and occlusal fit of metal-ceramic frameworks. MATERIAL AND METHODS: The study involved 10 patients with 3-unit metal-ceramic restorations produced using the DMLS technique. Using the silicone replica technique, we examined the marginal, axial and occlusal fit of the dental bridges before and after ceramic firing. The Shapiro-Wilks normality test and Student's paired t­test were implemented to analyze the mean differences in the marginal, axial and occlusal fit of the restorations before and after ceramic firing. A 95% confidence interval (CI) and discrepancy values at the level of 1% and 0.1% (p > 0.05) were applied. RESULTS: All the mean values of the measurements of marginal (156.08 µm), axial (95.75 µm) and occlusal (252.83 µm) gaps were lower before ceramic veneering than after ceramic veneering, when the mean value for the marginal gap was 178.17 µm, for the axial gap - 106.75 µm and for the occlusal gap - 266.00 µm. CONCLUSIONS: Porcelain firing caused no statistically significant differences in the discrepancy values of marginal, axial and occlusal fit. For clinical application, further improvement of the DMLS system is highly recommended. Marginal gaps in DLSM bridges significantly exceed the permissible inaccuracy values of 100-120 µm for prosthetic restorations.


Asunto(s)
Adaptación Marginal Dental , Porcelana Dental , Cerámica , Diseño Asistido por Computadora , Diseño de Prótesis Dental , Humanos
15.
J Prosthet Dent ; 124(5): 566.e1-566.e6, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32624223

RESUMEN

STATEMENT OF PROBLEM: Computer-aided design and computer-aided manufacturing (CAD-CAM) milling and 3-dimensional printing are readily available for the fabrication of interim restorations. However, studies comparing the marginal gap after a long period of function are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the marginal gap of interim crowns fabricated from different materials and with different techniques before and after receiving simulated oral stress. MATERIAL AND METHODS: Two conventional resins, a polymethyl methacrylate resin (Unifast Trad) and a bis-acryl resin (Protemp 4), a milled polymethyl methacrylate resin (Brylic Solid), and a 3-dimensionally printed bis-acrylate resin (Freeprint Temp) were evaluated. Interim crowns (n=10/group) were fabricated by using the conventional direct technique for Unifast Trad and Protemp 4, with a maxillary molar Dentiform tooth as a template and by using CAD-CAM for Brylic Solid and Freeprint Temp. After finishing and cementation, the marginal gap was measured at the middle of all surfaces and line angles. The average value from all 8 sites was used to represent the marginal gap of each specimen. Subsequently, all interim crowns were thermocycled (5000 cycles of 5 °C and 55 °C), and cyclic occlusal load with a 5-mm steel ball at central pit (100 000 at 100 N) and the marginal gap were remeasured. The effects of different material types and aging on marginal gap were analyzed with 2-way ANOVA. The difference in marginal gap before and after aging was analyzed by using the paired t test, and the increased marginal gap was analyzed with 1-way ANOVA (α=.05). RESULTS: Both the material types and the aging regimen had a significant effect on marginal gap (P<.001). The Unifast Trad group and the Protemp 4 group had a significantly larger marginal gap than the Brylic Solid group and the Freeprint Temp group, both before and after aging (P<.01). Each group had a significantly larger marginal gap after the aging regimen (P<.001). The increased marginal gap was greatest in the Unifast Trad group, which differed statistically from the Freeprint Temp group (P=.004) but not from the other groups (P>.05). CONCLUSIONS: The interim crowns fabricated with the Brylic Solid and the Freeprint Temp had a smaller marginal gap than those fabricated with Unifast Trad and Protemp 4, both before and after aging. The Unifast Trad group showed a significantly larger increase in marginal gap after the aging regimen than the Freeprint Temp group.


Asunto(s)
Diseño Asistido por Computadora , Diseño de Prótesis Dental , Cementación , Coronas , Adaptación Marginal Dental , Ensayo de Materiales , Polimetil Metacrilato
16.
Oper Dent ; 45(5): E227-E236, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32502270

RESUMEN

CLINICAL RELEVANCE: Using a material that optimizes marginal seal when using a margin elevation technique to manage deep class II cavities should enhance clinical outcomes. SUMMARY: Objectives: The purpose of this laboratory study was to perform a tridimensional interfacial gap evaluation of class II cavities with enamel and dentin cervical margins, before and after cyclic fatigue, restored with different nanohybrid resin composites.Methods and Materials: Standardized class II cavities were performed on 48 intact maxillary premolars, placing the mesial cervical margin 1 mm above the cement-enamel junction (CEJ) and the distal cervical margin 1 mm below the CEJ. Specimens were treated with two-step self-etch adhesive (Clearfil SE Bond2) and divided into six groups according to the restoration technique. Microcomputed Tomography imaging was executed before and after 1,000,000 cycles of chewing simulation at 50 N. Tridimensional interfacial gaps, expressed as cubic millimeters, were analyzed through a standardized software flowchart (Mimics). Data were analyzed with a two-way analysis of variance and Tukey post hoc tests (α=0.05).Results: Restoration technique (p=0.001) and chewing simulation (p=0.00001) significantly influenced interfacial gap on dentin but not on enamel. The post hoc test showed that, on dentin margins, flowable resins had a lower gap at baseline but a higher gap after chewing simulation, especially when a 2-mm-thick layer was applied, compared with nanohybrid and bulk-fill composites.Conclusions: Based on the obtained results, no differences in interfacial gap volume were found on enamel margins. On dentin margins, flowable resins showed better marginal seal at baseline, but they seem to be more prone to interfacial degradation during chewing simulation than traditional composites.


Asunto(s)
Resinas Compuestas , Restauración Dental Permanente , Preparación de la Cavidad Dental , Adaptación Marginal Dental , Materiales Dentales , Cementos de Resina , Programas Informáticos , Microtomografía por Rayos X
17.
Oper Dent ; 45(6): 598-607, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-32503033

RESUMEN

CLINICAL RELEVANCE: One-step self-etch adhesive systems provide a clinical time gain, decreasing the number of clinical steps. When a clinician is able to follow a simpler process of adhesion there is less chance of adhesive failure. SUMMARY: Objective: A systematic review and meta-analyses were performed to evaluate whether one-step self-etching (1SSE) adhesive systems are as effective as two-step self-etching (2SSE) adhesives in noncarious cervical lesion (NCCL) restorations.Methods: This systematic review was conducted according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and recorded in the PROSPERO (CRD42018096747). Electronic systematic searches were conducted in the following databases: PubMed/MEDLINE, Scopus, and Cochrane Library for published articles. Only randomized clinical trials that compared 1SSE with 2SSE adhesives systems were selected. The outcomes were retention, postoperative sensitivity, secondary caries, color match, marginal discoloration, marginal adaptation, and anatomical form.Results: The searches resulted in 476 studies. After applying the eligibility criteria, five randomized controlled trials were selected in which 822 restorations in NCCLs were distributed in 237 patients. The results showed no statistical difference between 1SSE and 2SSE in relation to retention (p=0.23; relative risk [RR]=1.55; 95% confidence interval [CI]=0.76, 3.19), postoperative sensitivity ( p=0.50; RR=3.00; 95% CI=0.13, 70.64), Secondary caries (p=0.63; RR=0.68; 95% CI=0.14, 3.31), color match (p=0.41; RR=0.64; 95% CI=0.23, 1.83), marginal discoloration (p=0.93; RR=1.02; 95% CI=0.65, 1.61), and anatomical form (p=0.56; RR=1.38; 95% CI=0.46, 4.13). However there was statistical difference in relation to marginal adaptation ( p=0.01; RR=1.95; 95% CI=1.14, 3.34).Conclusion: This systematic review with meta-analysis revealed that both 1SSE and 2SSE adhesive systems have comparable clinical effectiveness in a follow-up period of 12 to 24 months, except in relation to marginal adaptation.


Asunto(s)
Restauración Dental Permanente , Recubrimientos Dentinarios , Adhesivos , Resinas Compuestas , Cementos Dentales , Adaptación Marginal Dental , Humanos , Cementos de Resina , Cuello del Diente
18.
Am J Dent ; 33(3): 145-150, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32470240

RESUMEN

PURPOSE: To compare the dentin bonded external marginal integrity and the internal surface indentation hardness of bulk-fill and conventional resin-based composite (RBC) placed in both bulk and increments. METHODS: 120 MO and DO cavities were prepared in 60 extracted human third molars. The teeth were randomly divided into four groups of 15 teeth per group to be restored as follows: BB (bulk-fill RBC, placed in a 4 mm bulk increment), BL (bulk-fill RBC, placed in 2 mm incremental layers), CB (conventional RBC, placed in a 4 mm bulk increment), and CL (conventional RBC, placed in 2 mm incremental layers). Marginal gaps were measured at mesial and distal dentin gingival cavosurfaces of each tooth using scanning electron microscopy of epoxy resin replicas and Knoop hardness (KHN) was measured at three different RBC depths (1.8, 2.8 and 3.8 mm). Statistical analyses included one-way ANOVA with post-hoc Tukey's HSD, and paired-sample t-test or a nonparametric Wilcoxon signed-rank test, as appropriate. RESULTS: There was no significant effect of RBC restoration type on external marginal gap at the distal surface or at the mesial surface among the four groups tested (P> 0.05 in each instance), while no significant difference in external marginal gap was found between the mesial and distal surfaces within groups (P> 0.05 in each instance). The mean RBC internal surface KHN at 1.8 mm depth was significantly greater than at 2.8 mm and 3.8 mm depths in all tested groups (P< 0.05 for all instances), with a similar mean internal hardness between all groups. The bulk-fill RBC restorations demonstrated similar marginal gap formation and Knoop hardness to conventional universal RBC restorations under the conditions of this study. CLINICAL SIGNIFICANCE: Bulk-fill resin-based composite (RBC), from the perspective of marginal adaptation and internal hardness, may be a suitable alternative to conventional RBC.


Asunto(s)
Resinas Compuestas , Restauración Dental Permanente , Adaptación Marginal Dental , Materiales Dentales , Dureza , Humanos
19.
Oper Dent ; 45(5): 473-483, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32352353

RESUMEN

CLINICAL RELEVANCE: At 24 months, the dentin pretreatment with epigallocatechin-3-gallate did not impair the clinical performance of the adhesive Single Bond Universal regardless of the bonding strategy used. SUMMARY: Purpose: To evaluate the two-year effect of dentin pretreatment with epigallocatechin-3-gallate (EGCG) on the clinical performance of restorations of noncarious cervical lesions (NCCLs) with Single Bond Universal, applied in two different modes (self-etch and etch-and-rinse).Methods and Materials: In this randomized clinical trial, 33 volunteers were selected, and 156 NCCLs were assigned to four groups: ER, etch-and-rinse; ER-EGCG, 0.1% EGCG dentin pretreatment + etch-and-rinse; SE, self-etch; and SE-EGCG, 0.1% EGCG dentin pretreatment + self-etch. The NCCLs were restored with a nanofilled resin composite and evaluated at baseline and at six, 12, 18, and 24 months using FDI criteria for retention, marginal staining, marginal adaptation, caries, and postoperative sensitivity. Two evaluators were blinded to the treatments performed, and impressions were taken for resin replicas to allow indirect observations. Statistical analyses were performed with Kruskal-Wallis and McNemar tests with a significance level of 5%.Results: Six restorations (one from ER, two from SE, one from ER-EGCG, and two from SEEGCG) were lost at 24 months with no significant differences (p>0.05). The retention rates were 97.0% (ER and ER-EGCG), 94.1% (SE), and 94.2% (SE-EGCG). For marginal adaptation, a significant difference was detected between the baseline and 24 months for the SE group (p=0.0313). There were no statistical differences among all other evaluated criteria at 24 months, neither for each group at baseline nor for 24-month comparisons (p>0.05).Conclusions: The pretreatment with EGCG provided no benefit in the clinical performance of the adhesive regardless of the bonding strategy used. In addition, it adds an additional required step to the restorative procedure.


Asunto(s)
Catequina , Recubrimiento Dental Adhesivo , Resinas Compuestas , Cementos Dentales/uso terapéutico , Adaptación Marginal Dental , Restauración Dental Permanente , Dentina , Recubrimientos Dentinarios , Humanos , Cementos de Resina
20.
J Prosthet Dent ; 124(4): 476.e1-476.e6, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32451142

RESUMEN

STATEMENT OF PROBLEM: Adaptation between abutment and suprastructure plays a crucial role in the long-term success of implant-supported metal-ceramic crowns. Fabrication methods, the porcelain firing stage, and cementation techniques may affect the marginal adaptation between the crown and abutment. However, the information regarding this issue is sparse. PURPOSE: The purpose of this in vitro study was to compare marginal fit after the fabrication of cobalt-chromium alloy copings, porcelain firing, and cementation of metal-ceramic restorations that were fabricated with computer-aided design and computer-aided manufacturing (CAD-CAM) milling and direct metal laser sintering techniques. MATERIAL AND METHODS: Thirty straight tissue-level titanium abutments were screwed onto implant analogs. All specimens were embedded in acrylic resin and divided into 2 groups according to CAD-CAM milling and direct metal laser sintering fabrication of the metal coping. Fifteen cobalt-chromium implant-supported metal copings were fabricated by using the CAD-CAM milling technique and 15 by using the direct metal laser sintering technique. In both groups, marginal gap measurements between the cobalt-chromium copings and abutments were obtained before (T0) and after the placement of the ceramic veneer (T1) and after cementation (T2) by using a stereomicroscope with a magnification of ×40. The data were statistically evaluated by using 2-way ANOVA and the Tukey post hoc test (α=.05). A t test was used to determine whether there were significant differences between the fabrication techniques (α=.05). RESULTS: A significant difference in the fabrication stages was found in the direct metal laser sintering group. The direct metal laser sintering coping group and porcelain applied direct metal laser sintering group had a statistically lower marginal gap value than the cemented direct metal laser sintering group (P=.021, P=.038). The direct metal laser sintering coping group had a lower marginal gap value than the CAD-CAM milling coping group, although the difference was not statistically significant (P=.216). CONCLUSIONS: Porcelain firing and cementation increased the marginal gap between the crown and abutment. No statistically significant differences were found between the direct metal laser sintering and CAD-CAM milling techniques in terms of marginal fit.


Asunto(s)
Implantes Dentales , Aleaciones de Cerámica y Metal , Cementación , Cerámica , Diseño Asistido por Computadora , Coronas , Adaptación Marginal Dental , Porcelana Dental , Diseño de Prótesis Dental
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