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1.
Braz Dent J ; 31(3): 264-271, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32667515

RESUMEN

The objective of this work was to evaluate the effects of in vitro and in situ biodegradation on the surface characteristics of two resin cements and a hybrid ceramic system. One hundred and eighty specimens (4X1.5mm) of each material (Maxcem Elite, NX3 Nexus and Vita Enamic) were made and randomly distributed in twelve groups (n=15) according to the material and biodegradation method. The specimens were then submitted to the following challenges: storage in distilled water 37 ºC for 24 h or 7 days, storage for 7 days, at 37 ºC, in stimulated saliva or in situ. The in situ stage corresponded to the preparation of 15 intraoral palatal devices, used for 7 days. Each device presented 3 niches, where a sample of each materials was accommodated. Specimens from both saliva and in situ groups suffered a cariogenic challenge, corresponding to the application of a solution of 20% of sucrose, 10 times throughout each day. After each biodegradation method, the surface roughness (Ra), Vickers hardness (VHN) and scanning electron microscopy (SEM) analyzes were performed. The data collected were evaluated by Levene test, two-way ANOVA and Tukey`s test (α=5%). The in situ challenge promoted the greater biodegradation, regardless of the material. Regarding the materials, the Vita Enamic VHN was negatively affected by all biodegradation methods and the Nexus NX3 presented better performance than the self-adhesive cement tested. Therefore, within the conditions of this work, it was concluded that in situ biodegradation can affect negatively the surface characteristics of indirect restorative materials.


Asunto(s)
Materiales Dentales , Cementos de Resina , Cerámica , Dureza , Ensayo de Materiales , Propiedades de Superficie
2.
J Adhes Dent ; 22(4): 383-391, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32666064

RESUMEN

PURPOSE: To evaluate the influence of different cleaning methods on the resin bond strength to contaminated translucent 3Y-TZP ceramic. MATERIALS AND METHODS: A total of 133 airborne-particle abraded (0.1 MPa) zirconia specimens were divided into 7 groups. Uncontaminated zirconia specimens were either not cleaned (UN) or cleaned with cleaning paste (Ivoclean) (UP1). After contamination by saliva and blood immersion, zirconia specimens were cleaned using either distilled water rinsing (CW), 99% isopropanol in an ultrasonic bath (CI), cleaning paste according to manufacturer's instructions (CP1), cleaning paste with additional rubbing (CP2), or additional airborne-particle abrasion at 0.1 MPa (CA). Three specimens from each group were examined by x-ray photoelectron spectroscopy (XPS). For each group, sixteen Plexiglas tubes filled with composite resin (Clearfil FII, Kuraray Noritake) were bonded to the zirconia specimens using a primer (Clearfil Ceramic Primer Plus, Kuraray Noritake) and luting composite (Panavia V5, Kuraray Noritake). Before measuring tensile bond strength, specimens were stored in distilled water for 3 or 150 days plus 37,500 thermal cycles. RESULTS: After 3 days, no group showed significantly different TBS compared to the control group UN (p > 0.05). However, groups CW and CI showed significantly lower TBS than all other groups after 150 days (p ≤ 0.05). XPS analysis revealed more organic residue on zirconia surfaces of groups CW and CI than on the other groups. CONCLUSION: Cleaning with the cleaning paste and airborne-particle abrasion were effective in removing saliva and blood contamination and enhancing bond strength.


Asunto(s)
Recubrimiento Dental Adhesivo , Porcelana Dental , Cerámica , Análisis del Estrés Dental , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Cementos de Resina , Propiedades de Superficie , Resistencia a la Tracción , Circonio
3.
J Adhes Dent ; 22(4): 421-431, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32666069

RESUMEN

PURPOSE: To investigate the effects of 1-year water storage and surface treatments on shear bond strength (SBS) of two composite cements bonded to resin matrix CAD-CAM ceramics (RMCs) and on the mechanical properties of RMCs. MATERIALS AND METHODS: Three types of RMCs were tested: 1. polymer-infiltrated hybrid ceramic (PIHC, Enamic, VITA Zahnfabrik); 2. resin nanoceramic (RNC, Lava Ultimate, 3M Oral Care); and 3. flexible hybrid ceramic (FHC, Cerasmart, GC). One indirect laboratory composite (ILC, Epricord, Kuraray Noritake) was used as control. For each material, 60 plates (14 x 7 x 1 mm) were prepared for the SBS test and submitted to three different surface treatments: following manufacturer's instructions, non-thermal atmospheric plasma application (30 s), and plasma + bonding agent. Two composite cements were tested: RelyX Ultimate (3M Oral Care) and Panavia V5 (Kurarary Noritake). Two resin cylinders (1.5 mm diameter x 1.5 mm height) were bonded to each plate (n = 10), with one tested after 24-h storage in distilled water and the other after 1 year of storage in distilled water. Twenty rectangular bars (12 x 2 x 1 mm) of each indirect material were prepared and submitted to the 3-point flexural test after 24-h or 1-year water storage to determine the elastic modulus (EM) and flexural strength (FS) (n = 10). Fractured samples were also examined with SEM and energy dispersive x-ray spectroscopy (EDS). SBS data were analyzed by four-way ANOVA, and EM and FS data by two-way ANOVA, followed by Tukey's post-hoc test (α = 0.05). RESULTS: Groups treated in accordance with manufacturer's instructions exhibited higher SBS than did plasma and plasma + bonding agent groups for all indirect materials, composite cements, and storage periods tested. In general, RelyX Ultimate displayed higher mean SBS than did Panavia V5, except for some groups of ILC where manufacturer's instructions were followed. After 1-year storage in water, all groups exhibited a significant reduction in SBS, except for some groups that following manufacturer's instructions. ILC showed the lowest values of EM and FS. Among the CAD-CAM materials, FHC exhibited the lowest EM and highest FS means, while PIHC possessed the highest EM and lowest FS means for both storage periods. CONCLUSIONS: In general, following the respective manufacturer's instructions yielded the best bond strength results. For most materials, 1-year water storage decreased bond strength of composite cements to RMCs, as well as their FS, while increasing their EM. Microstructure and composition influenced the mechanical properties studied.


Asunto(s)
Cerámica , Recubrimiento Dental Adhesivo , Diseño Asistido por Computadora , Ensayo de Materiales , Polímeros , Cementos de Resina , Resistencia al Corte , Propiedades de Superficie
5.
Bone Joint J ; 102-B(7_Supple_B): 105-111, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32600211

RESUMEN

AIMS: The purpose of this study is to examine six types of bearing surfaces implanted at a single institution over three decades to determine whether the reasons for revision vary among the groups and how long it takes to identify differences in survival. METHODS: We considered six cohorts that included a total of 1,707 primary hips done between 1982 and 2010. These included 223 conventional polyethylene sterilized with γ irradiation in air (CPE-GA), 114 conventional polyethylene sterilized with gas plasma (CPE-GP), 116 crosslinked polyethylene (XLPE), 1,083 metal-on-metal (MOM), 90 ceramic-on-ceramic (COC), and 81 surface arthroplasties (SAs). With the exception of the COC, all other groups used cobalt-chromium (CoCr) femoral heads. The mean follow-up was 10 (0.008 to 35) years. Descriptive statistics with revisions per 100 component years (re/100 yr) and survival analysis with revision for any reason as the endpoint were used to compare bearing surfaces. RESULTS: XLPE liners demonstrated a lower cumulative incidence of revision at 15 years compared to the CPE-GA and CPE-GP groups owing to the absence of wear-related revisions (4% for XLPE vs 18%, p = 0.02, and 15%, p = 0.003, respectively). Revisions for adverse local tissue reactions occurred exclusively among the MOM (0.8 re/100 year) and SA groups (0.1 re/100 year). The revision rate for instability was lower among hips with 36 mm and larger head sizes compared to smaller head sizes (0.2% vs 2%, p < 0.001). CONCLUSION: The introduction of XLPE has eliminated wear-related revisions through 15-year follow-up compared to CPE-GP and CPE-GA. Dislocation incidence has been reduced with the introduction of larger diameter heads but remains a persistent concern. The potential for adverse local tissue reactions with MOM requires continued follow-up. Cite this article: Bone Joint J 2020;102-B(7 Supple B):105-111.


Asunto(s)
Artroplastia de Reemplazo de Cadera/instrumentación , Prótesis de Cadera , Diseño de Prótesis , Falla de Prótesis/tendencias , Adulto , Anciano , Cerámica , Aleaciones de Cromo , Estudios de Cohortes , Estudios de Seguimiento , Humanos , Inestabilidad de la Articulación/cirugía , Masculino , Prótesis Articulares de Metal sobre Metal , Persona de Mediana Edad , Polietileno , Reoperación/estadística & datos numéricos , Virginia
6.
Int J Prosthodont ; 33(4): 418-428, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32639702

RESUMEN

PURPOSE: To compare the influence of surface roughness and accelerated aging on the mechanical properties of polymer-based and ceramic CAD/CAM materials. MATERIALS AND METHODS: Three polymers (Lava Ultimate [LVU], VITA ENAMIC [ENA], and Shofu Block HC [SFB]) and one ceramic (IPS Empress CAD [EMP]) were selected for this study. The specimens were treated with the aim of measuring surface roughness (Ra [mm]) and its influence on the mechanical properties. The treatments were: polishing (POL); etching with 9.6% hydrofluoric acid for 90 seconds (ETC); airborne-particle abrasion with 50-µm aluminum oxide at 2-bar pressure (SBT); and airborne-particle abrasion with 50-µm aluminum oxide at 2-bar pressure plus etching with 9.6% hydrofluoric acid (SAC) for 90 seconds. Before and after the accelerated aging (AA) protocol (30,000 cycles, 5°C and 55°C), the specimens were subjected to the 3-point bending test. The data were analyzed with two-way and three-way ANOVA and post hoc Tukey test (P < .05). RESULTS: The surface roughness ranged from 0.24 µm to 1.96 µm, with statistically significant differences (P < .05). The highest surface roughness, in descending order, was exhibited by: LVU > SFB > EMP > ENA. The AA demonstrated an influence on the flexural strength of LVU, ENA, and SFB. The surface treatment did not affect the flexural moduli of the materials tested. The LVU and SFB showed decreased moduli of resilience after the AA; however, modulus of resilience was not influenced by surface treatment. CONCLUSION: The polymer-based materials were affected by AA. In addition, surface treatment could jeopardize their mechanical properties in certain conditions.


Asunto(s)
Cerámica , Diseño Asistido por Computadora , Materiales Dentales , Porcelana Dental , Ensayo de Materiales , Propiedades de Superficie
7.
Shanghai Kou Qiang Yi Xue ; 29(2): 133-137, 2020 Apr.
Artículo en Chino | MEDLINE | ID: mdl-32626874

RESUMEN

PURPOSE: To analyze the effect of porcelain layer thicknesses and substrates on color properties and translucency of IPS e.max LT porcelain laminate veneers used to restore tetracycline stained teeth. METHODS: Porcelain specimens with different core and veneer thickness (veneer/core thickness: 0.25 mm/0.25 mm, 0.50 mm/0.25 mm, 0.25 mm/0.50 mm, 0.50 mm/0.50 mm, and 0.25 mm/0.75 mm) were fabricated by heat-press layering technique. CIE L*a*b* parameters were measured under simulated tetracycline backgrounds and black and white backgrounds by a spectrophotometer, color differences ΔE001 between specimens on simulated tetracycline backgrounds and backgrounds themselves and ΔE002 between specimens on simulated tetracycline backgrounds and white background were calculated. The translucent parameter(TP) was also calculated. The data were submitted to statistical analysis with SPSS 17.0 software package. RESULTS: ΔE001 increased with increase of thickness of the core and veneer layer, but there was no significant difference between 0.25 mm and 0.50 mm core thickness groups with 0.50 mm veneer in thickness (P>0.01). Except for light grey, ΔE002 decreased over other substrates with increase of thickness of the core and veneer layer, but there was no significant difference between 0.50 mm and 0.75 mm core thickness groups with 0.25 mm veneer in thickness (P>0.01). Both ΔE001 and ΔE002 were significantly different over different substrates(P<0.01). TP decreased as the increase of core and veneer thickness and TP was significantly different with different core and veneer thickness(P<0.01). CONCLUSIONS: Both the core/veneer thickness and the substrate have significant influence on color matching and masking ability of IPS e.max LT porcelain laminate veneers used to restore tetracycline stained teeth. As for IPS e.max LT porcelain veneers, the color property was the best when yellowish tetracycline stained teeth were restored, while the light grey was worst. The thickness of core and veneer has significant influence on the translucency of porcelain laminate veneers.


Asunto(s)
Porcelana Dental , Coronas con Frente Estético , Cerámica , Color , Ensayo de Materiales , Tetraciclina
8.
J Oral Sci ; 62(3): 259-264, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32581175

RESUMEN

In this study, the wettability, cell viability, and roughness of an experimental dense bovine hydroxyapatite [Ca10(PO4)6(OH)2] ceramic block were evaluated so that, in the future, it could be used as a base material for dental implants. The results to commercial zirconia and a commercially pure titanium (Ti) alloy were compared. The surface roughness and contact angles were measured. An in vitro evaluation was conducted by means of tests in which pre-osteoblastic MC3T3-E1 cells were placed in indirect and direct contact with these materials. For cell viability, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and crystal violet test were conducted. A qualitative analysis was conducted using variable pressure scanning electron microscopy (SEM). No statistically significant differences were observed in wettability and roughness tests among the groups. In both the MTT assay and crystal violet test, all groups demonstrated satisfactory results without cytotoxicity. SEM showed cell adhesion and cell proliferation results on the material surfaces after 24 h and 48 h. In conclusion, this dense Ca10 (PO4)6(OH)2 ceramic can be considered as a potential biocompatible material.


Asunto(s)
Cerámica , Durapatita , Animales , Bovinos , Proliferación Celular , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Propiedades de Superficie , Titanio , Humectabilidad
9.
J Esthet Restor Dent ; 32(5): 521-529, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32598095

RESUMEN

OBJECTIVE: To evaluate the effects of human saliva decontamination protocols on bond strength of resin cement to zirconia (Y-PSZ), wettability, and microbial decontamination. MATERIALS AND METHODS: Zirconia plates were sandblasted and divided into (a) not contaminated, (b) contaminated with human saliva and: (c) not cleaned, (d) cleaned with air-water spray, (e) cleaned with 70% ethanol, (f) cleaned with Ivoclean, or (g) cleaned with nonthermal atmospheric plasma (NTAP). The wettability and microbial decontamination of the surfaces were determined after saliva contamination or cleaning. Monobond Plus (Ivoclar Vivadent) was applied after cleaning, followed by Variolink LC (Ivoclar Vivadent). The samples were stored 1 week before shear bond strength (SBS) testing, and data (SBS and wettability) were analyzed by one-way analysis of variance and Tukey test (α = .05). RESULTS: Saliva contamination reduced SBS to zirconia compared to not contaminated. Both Ivoclean and NTAP produced higher SBS compared to not cleaned and were not significantly different from the not contaminated. Ivoclean produced the highest contact angle, and NTAP the lowest. With the exception of using just water-spray, all cleaning protocols decontaminated the specimens. CONCLUSIONS: Both Ivoclean and NTAP overcame the effects of saliva contamination, producing an SBS to zirconia comparable to the positive control. CLINICAL SIGNIFICANCE: Dental ceramics should be cleaned prior to resin cementation to eliminate the effects of human saliva contamination, and Ivoclean and NTAP are considered suitable materials for this purpose.


Asunto(s)
Recubrimiento Dental Adhesivo , Cerámica , Descontaminación , Análisis del Estrés Dental , Humanos , Ensayo de Materiales , Cementos de Resina , Propiedades de Superficie , Humectabilidad , Circonio
10.
Niger J Clin Pract ; 23(6): 792-797, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32525113

RESUMEN

Background: There is no information about the shear bond strengths (SBS) of zirconia ceramic to primary tooth dentin. Aim: To investigate the effect of different surface treatments and cements on the shear bond strength (SBS) of zirconia ceramic to primary tooth dentin. Materials and Methods: Prepared zirconia bars were distributed into four groups according to surface treatment procedure: control, sandblasting, CoJet and hot etching. The zirconia specimens in each group were further divided into subgroups according to cement (n = 13): self-adhesive resin (Rely-X Unicem), resin-modified glass ionomer (Ketac-Cem Plus), and universal bioactive (BioCem). Zirconia specimens were bonded to the primary tooth dentin surface by cement. SBS was measured, and the data were subjected to two-way ANOVA and Tukey's tests. Results: Statistical differences were observed in the surface treatment procedures for Rely-X Unicem (P < 0.05), but no statistically significant differences were found in the sandblasting, CoJet and hot-etching groups for Ketac-Cem Plus (P > 0.05). For BioCem, the SBS value for the hot etching group was significantly lower than those for the CoJet and sandblasting groups (P < 0.05). The SBS values for the Rely-X Unicem subgroups (sandblasting, CoJet and hot etching) were significantly higher than those for the other cements (P < 0.05). Conclusion: The bond strength of zirconia ceramic to primary tooth dentin is affected by surface treatments and cements.


Asunto(s)
Cerámica/química , Recubrimiento Dental Adhesivo , Dentina , Cementos de Resina/química , Resistencia al Corte , Diente Primario , Circonio/química , Resinas Acrílicas , Adhesivos , Cementos de Ionómero Vitreo , Humanos , Ensayo de Materiales , Dióxido de Silicio , Propiedades de Superficie
11.
Artículo en Inglés | MEDLINE | ID: mdl-32559032

RESUMEN

Subgingival margins are often associated with adverse periodontal reactions, such as recession and gingival inflammation. The purpose of this cross-sectional dual-center study was to evaluate the periodontal health and stability of intrasulcular margins, comparing two prosthetic margin preparations: subgingival chamfer (SC) and subgingival feather-edge (SF) with gingival curettage. Ninety-six patients with 205 crowns (buccal margin 0.5 mm into the gingival sulcus) were included in the study. SF, gingival curettage, and intrasulcular restorative margin were prepared on 109 crowns; SC was prepared on 96. Restorations were in place for a mean of 55.9 months (range: 12 months to 10 years). No significant differences were found regarding probing depth between the two groups (mean buccal: 1.6 mm; mean interproximal: 2.3 mm). Significant increased recession was present around SCs, showing a higher margin-exposure frequency (buccal: 19.8% vs 3.7%; interproximal: 5.2% vs 1.4%). SC showed 8.5 times the risk of margin exposure compared to SF, men 5.5 times compared to women, and smokers 3.7 times compared to nonsmokers. Follow-up time was not a significant factor. SC sites showed a tendency for reduced buccal bleeding on probing compared to SF sites (3.0% vs 12.1%), but no significant difference was seen in a regression model. Plaque presence increased the risk of bleeding (4.1×), and women presented a higher risk of bleeding than men (3×). Subgingival margins can provide adequate periodontal health and stability if restorative procedures are well controlled and if patients are enrolled in an adequate maintenance program. SF with intrasulcular margin favors facial soft tissue stability, as reduced gingival recession was observed. The technique should be carefully applied to promote an adequate periodontal response.


Asunto(s)
Coronas , Recesión Gingival , Cerámica , Estudios Transversales , Femenino , Humanos , Masculino , Índice Periodontal
12.
Shanghai Kou Qiang Yi Xue ; 29(1): 13-18, 2020 Feb.
Artículo en Chino | MEDLINE | ID: mdl-32524114

RESUMEN

PURPOSE: To study the optical properties of two common dental light curing units and the optical properties of the transmitted light after transmitting glass ceramics. METHODS: Two types of glass-ceramic disc named IPS e.max CAD and IPS Empress CAD were produced by CAD/CAM technology, and the colors of A2 and A3 were chosen for each type of glass ceramic, then divided into 4 groups. Eight discs were made 0.5 mm to 4.0 mm thick in each group, the total number was 32. Spectra irradiance meter and power meter were used to measure the central wavelengths and irradiance of 3 power modes of 2 new LED light curing units before and after transmitting glass-ceramic discs. Statistical analysis was performed using SPSS 25.0 software package. RESULTS: Under different power modes of light curing units, different types and colors of glass ceramics, the central wavelengths of transmitted light were significantly different (P<0.05). Under different power modes of light curing units, different types, colors and thicknesses of glass ceramics, the irradiance of transmitted light was significantly different (P<0.05). CONCLUSIONS: The power mode of light curing unit, the type and color of the glass ceramic have influence on the central wavelength of the transmitted light, but the thickness of the glass ceramic has no influence on the central wavelength of the transmitted light. The power mode of the light curing unit, the type, color, and thickness of the glass ceramic have influence on the irradiance of the transmitted light, in which glass ceramic thickness has the most significant effect on the attenuation of the irradiance of the transmitted light.


Asunto(s)
Cerámica , Luces de Curación Dental , Color , Diseño Asistido por Computadora , Porcelana Dental , Ensayo de Materiales , Cementos de Resina , Propiedades de Superficie
13.
Shanghai Kou Qiang Yi Xue ; 29(1): 19-24, 2020 Feb.
Artículo en Chino | MEDLINE | ID: mdl-32524115

RESUMEN

PURPOSE: The purpose of this study was to observe the friction and wear characteristics of dental fluorapatite glass ceramics, feldspathic porcelain and natural tooth in dry friction and saliva lubrication. METHODS: Two kinds of veneering porcelain (IPS-emaxcream and Vita vm9) coated zirconia-decorative porcelain double-layer material sample were prepared (size 20 mm × 20 mm × 4.5 mm), each group had 20 specimens. Friction and wear tests were carried out on 2 kinds of zirconia-decorative porcelain sample under dry friction and saliva accompanying environment respectively by setting different sizes of vertical load and sliding frequency using MMV-1 friction and wear testing machine. SPSS 17.0 software package was used for one-way ANOVA and t test to determine whether there were differences in friction coefficient and wear amount between two groups. RESULTS: The dynamic friction coefficient and wear amount of fluorapatite glass ceramics under saliva lubrication condition were significantly greater than those under dry friction condition. On the contrary to fluorapatite glass ceramics, the dynamic friction coefficient and wear amount of feldspathic decorative ceramics under dry friction condition were significantly greater than those under saliva lubrication condition. Under dry friction and saliva lubrication, the wear amount of fluorapatite glass ceramics was significantly smaller than that of feldspathic decorative ceramics. Scanning electron microscopy showed that under saliva lubrication condition, fluorapatite glass ceramics and the corresponding natural teeth had more severe wear surface than dry friction. Under dry friction condition, feldspathic decorative porcelain and corresponding natural teeth wear more seriously than fluorapatite glass ceramic, and the difference in saliva lubrication condition was relatively small. CONCLUSIONS: Compared with feldspathic decorative porcelain, fluorapatite glass ceramics and natural teeth shows superior wear resistance under dry friction condition. The addition of saliva can reduce the difference between the friction and wear performance of the two decorative porcelains.


Asunto(s)
Cerámica , Porcelana Dental , Apatitas , Fricción , Ensayo de Materiales , Propiedades de Superficie , Circonio
14.
Shanghai Kou Qiang Yi Xue ; 29(1): 36-39, 2020 Feb.
Artículo en Chino | MEDLINE | ID: mdl-32524118

RESUMEN

PURPOSE: To investigate the effect of ultrasonic scaling on micro-leakage of all-ceramic crowns. METHODS: 48 first premolars of the similar shape and size were collected and prepared by one attending doctor. Two groups were randomly divided (zirconia crown group and glass ceramic crown group, with 24 in each group), and each group was randomly divided into two subgroups (resin cement group and resin modified glass cement subgroup, n=6). After the crowns were bonded and solidified for 24 h, 3 samples were randomly selected from each subgroup for ultrasonic scaling for 60 s, and the other 3 samples were used as the negative control group. After all samples were soaked in 5% fuchsin solution at room temperature for 48 h, buccal and lingual incisions were made, and double-blind scoring was performed for micro-leakage at the crown edge of each sample. SPSS 17.0 software package was used for statistical analysis. RESULTS: There were significant differences between the negative group and the ultrasonic group in micro-leakage of crowns which were cemented with resin modified glass cement(P<0.05), but there was no significant difference between the negative group and the ultrasonic group in micro-leakage of crowns which were cemented with resin cement(P>0.05). When the same adhesive was used, there was significant difference in microleakage between the zirconia crown and the glass-ceramic crown, whether ultrasonic supragingival scaling was performed or not(P<0.05). CONCLUSIONS: Ultrasonic scaling had significant effect on micro-leakage of crowns which were cemented with resin modified glass cement, and but had no significant effect on micro-leakage of crowns which were cemented with resin cement.


Asunto(s)
Filtración Dental , Cementación , Cerámica , Coronas , Cementos Dentales , Cementos de Ionómero Vitreo , Humanos , Ensayo de Materiales , Cementos de Resina , Ultrasonido
15.
Shanghai Kou Qiang Yi Xue ; 29(1): 46-50, 2020 Feb.
Artículo en Chino | MEDLINE | ID: mdl-32524120

RESUMEN

PURPOSE: To investigate the effect of dental varnish containing fluoride either with casein phosphopeptide-amorphous calcium phosphate(CPP-ACP) or bioglass on root caries. METHODS: The active roots collected in Peking University People's Hospital from April 2017 to October 2018 were randomly divided into group A, group B, group C, and group D, each with 18 teeth. All groups received toothbrushing containing fluoride, in addition, group B received another 5% sodium fluoride, group C added 5% sodium fluoride + CPP-ACP, and group D added 5% sodium fluoride + bioglass. The severity, surface roughness and mineral concentration of root caries before and after brushing were observed. SPSS 23.0 software package was used to determine the correlation between root severity and surface roughness. RESULTS: After 50 days of brushing, the hardness of group B, C and D was significantly improved (P<0.05), and was significantly better than that of group A (P<0.05). The hardness was the highest in group D after 50 days of brushing, followed by group C and B, with significant difference(P<0.05). The surface roughness scores of group B and C were significantly higher than those of group A and D after 7 days of brushing(P<0.05). The surface roughness scores of group B were significantly higher than those of group A, C and D after 14 days of brushing(P<0.05). The surface roughness scores of group D were significantly higher than those of group B and C after 50 days of brushing(P<0.05). The severity score of root caries in group A was negatively correlated with surface roughness (P<0.05). The mineral concentration of each group was increased 50 days after brushing (P<0.05). CONCLUSIONS: Application of dental varnish containing fluoride either with CPP-ACP or bioglass can effectively prevent root caries. Compared with CPP-ACP, bioglass is more stable, and can effectively improve the mineral concentration on tooth surface.


Asunto(s)
Caries Dental , Caries Radicular , Cariostáticos , Caseínas , Cerámica , Fluoruros , Humanos , Minerales , Pintura , Remineralización Dental
16.
J Environ Manage ; 268: 110710, 2020 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-32510444

RESUMEN

The electrochemical oxidation of the antibiotic Norfloxacin (NOR) in chloride media on different anodic materials was studied at two different electrochemical reactors. The results were compared with those obtained in sulphate media. The anodes under study were a commercial boron-doped diamond (BBD) and two different ceramic electrodes based on tin oxide doped with antimony oxide in the presence (CuO) and absence (BCE) of copper oxide as sintering aid. The reactors employed were a one-compartment reactor (OCR) and a two-compartment one with a membrane separating both electrodes (EMR). The use of the membrane clearly enhanced both NOR degradation and TOC mineralization for all the anodic materials studied since some parallel reactions were avoided. Additionally, two different pathways for NOR oxidation were observed as a function of the reactor employed. The EMR also favoured the ionic by-products generation and the electrolyte dechlorination. NO3- increased with the oxidation power of the anode employed and it was also enhanced by the EMR use. Chloride media favours ceramic electrodes performance independently of the reactor employed as they did not generate an excess of oxidants as BDD did. The BCE electrode is an interesting alternative to BDD since although its oxidative power was lower, it presented similar current efficiency with lower energy consumption.


Asunto(s)
Contaminantes Químicos del Agua , Boro , Cerámica , Diamante , Electrodos , Oxidación-Reducción
17.
Oral Health Prev Dent ; 18(3): 529-536, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32515424

RESUMEN

PURPOSE: To evaluate the effect of pre-treatment air abrasion of surfaces using bioactive glass 45S5 on the progression of erosion in bovine enamel induced by a common soft drink. MATERIALS AND METHODS: Twelve intact bovine incisors were selected and 24 enamel samples were prepared and randomly assigned to two groups (n = 12): 1. control group, no anti-erosive treatment; 2. experimental group: samples were air abraded with bioglass 45S5 before the erosive challenge. The enamel samples were submitted to erosive cycling using a common soft drink. Enamel surface loss was evaluated using optical profilometry; surface microhardness and roughness changes were determined using Vickers method and Vertical Scanning Interferometry, respectively. In addition, SEM observations and EDS analysis were performed to detect any alterations in surface morphology and mineral content. The data were statistically analysed using one-way ANOVA and Tukey's post-hoc test at a significance level of α = 0.05. RESULTS: The experimental group exhibited less (18.7%) surface loss than did the control group (p < 0.05), while also presenting a statistically significantly smaller decrease in surface microhardness compared to the control group after erosive cycling (p < 0.05). However, neither group showed a statistically significant change in surface roughness (p > 0.05). After the treatments, changes in surface morphology and mineral content of enamel were observed. CONCLUSIONS: Surface pre-treatment using air abrasion bioglass 45S5 may help prevent enamel erosion induced by excessive consumption of soft drinks. Further clinical trials are needed to confirm the effectiveness of this method and its clinical significance.


Asunto(s)
Erosión de los Dientes , Abrasión Dental por Aire , Animales , Bovinos , Cerámica , Esmalte Dental , Vidrio , Propiedades de Superficie
18.
Quintessence Int ; 51(7): 538-544, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32500861

RESUMEN

The prototyping protocol to evaluate and make the potential adjustments prior to finalization of the monolithic restorations was described by two clinical situations. In the first case report, following the digital impressions using an intraoral scanner (3Shape Trios, 3Shape) for an implant-supported four-unit fixed dental prosthesis, a digital design (3Shape Dental System, 3Shape) was performed and a prototype using subtractive CAM (milling) (PMMA, Telio CAD, Ivoclar Vivadent) was fabricated. The second case highlights the 3D-printed prototyping (additive CAM) (Sheraprint Model Plus UV, Shera) following digital impressions using an intraoral scanner and digital design in a patient requiring two opposing open-end three-unit fixed dental prostheses. By means of prototyping, the esthetic, fitting, and functional properties could be tested and the adjustments were completed on the prototypes. It is suggested that prototyping is an efficient tool that minimizes the clinical adjustment need for the final restoration while improving the communication between the dental practitioner and the technician.


Asunto(s)
Diseño Asistido por Computadora , Diseño de Prótesis Dental , Cerámica , Coronas , Porcelana Dental , Odontólogos , Humanos , Impresión Tridimensional , Rol Profesional
19.
Quintessence Int ; 51(7): 566-576, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32500864

RESUMEN

OBJECTIVES: Long-term retrospective evaluation of the survival rate and the technical and biologic outcomes of all-ceramic inlays and onlays in premolars and molars. METHOD AND MATERIALS: Fifty-four patients treated as part of a prospective clinical trial and having received 157 inlays and 27 onlays made out of a leucite-reinforced glass-ceramic (IPS Empress) in premolars and molars, were invited to the present follow-up examination. The survival of the restorations was evaluated. The biologic outcomes were assessed by measuring the pocket probing depth (PPD), the Plaque Index (PI), and the Sulcus Bleeding Index (SBI). The technical behavior was evaluated using modified US Public Health Service criteria (modUSPHS). Finally, patient satisfaction was recorded with a questionnaire. Data of patients and restored teeth were analyzed descriptively, and continuous variables were given in mean values and standard deviations. For the analysis of the restoration survival over time, the Kaplan-Meier survival estimate was calculated. The level of statistical significance was set at P < .05. RESULTS: Thirty-six patients (20 women, 16 men; mean age 50.9 years) with 132 restorations, 107 inlays and 25 onlays, were examined after a mean observation time of 11.2 ± 4.3 years. The overall 11-year survival rate of the 132 restorations was 80.3%. Inlays exhibited an 11-year survival rate of 80.4% and onlays of 80.0%. Twenty-two technical complications occurred. Ceramic fractures (10.6%) and chipping (2.3%) were the most frequent complications. Six biologic complications occurred (4.5%). CONCLUSION: Glass-ceramic inlays and onlays presented favorable long-term clinical survival and success rates. Technical complications were predominant, and biologic problems remained rare. More clinical long-term data are needed.


Asunto(s)
Porcelana Dental , Incrustaciones , Cerámica , Fracaso de la Restauración Dental , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Estudios Retrospectivos
20.
PLoS One ; 15(5): e0232906, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32459797

RESUMEN

Mediterranean Early Iron Age chronology was mainly constructed by means of Greek Protogeometric and Geometric ceramic wares, which are widely used for chronological correlations with the Aegean. However, Greek Early Iron Age chronology that is exclusively based on historical evidence in the eastern Mediterranean as well as in the contexts of Greek colonisation in Sicily has not yet been tested by extended series of radiocarbon dates from well-dated stratified contexts in the Aegean. Due to the high chronological resolution that is only achievable by (metric-scale) stratigraphic 14C-age-depth modelling, the analysis of 21 14C-AMS dates on stratified animal bones from Sindos (northern Greece) shows results that immediately challenge the conventional Greek chronology. Based on pottery-style comparisons with other sites, the new dates for Sindos not only indicate a generally higher Aegean Early Iron Age chronology, but also imply the need for a revised understanding of the Greek periodisation system that will foreseeably have a major impact on our understanding of Greek and Mediterranean history.


Asunto(s)
Arqueología/métodos , Cerámica/historia , Datación Radiométrica/métodos , Animales , Cerámica/análisis , Cronología como Asunto , Fósiles/historia , Grecia , Historia Antigua , Humanos , Sicilia
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