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1.
J Esthet Restor Dent ; 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32955762

RESUMO

OBJECTIVE: To review the historical and current periodontal phenotype classifications evaluating methods and characteristics. Moreover, to identify and classify the methods based on periodontal phenotype components. OVERVIEW: Several gingival morphology studies have been frequently associated with different terms used causing confusion among the readers. In 2017, the World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions recommended to adopt the term "periodontal phenotype". This term comprises two terms, gingival phenotype (gingival thickness and keratinized tissue width) and bone morphotype (buccal bone plate thickness). Furthermore, gingival morphology has been categorized on "thin-scalloped", "thick-scalloped" and "thick-flat" considering the periodontal biotype. However, by definition, the term phenotype is preferred over biotype. Periodontal phenotype can be evaluated through clinical or radiographic assessments and may be divided into invasive/non-invasive (for gingival thickness), static/functional (for keratinized tissue width), and bi/tridimensional (for buccal bone plate thickness) methods. CONCLUSIONS: "Thin-scalloped," "thick-scalloped," and "thick-flat" periodontal biotypes were identified. These three periodontal biotypes have been considered in the World Workshop but the term periodontal phenotype is recommended. Periodontal phenotype is the combination of the gingival phenotype and the bone morphotype. There are specific methods for periodontal phenotype evaluation. CLINICAL SIGNIFICANCE: The term periodontal phenotype is currently recommended for future investigations about gingival phenotype and bone morphotype. "Thin-scalloped," "thick-scalloped," and "thick-flat" periodontal phenotypes can be evaluated through specific methods for gingival thickness, keratinized tissue width, and buccal bone plate thickness evaluation.

2.
J Appl Biomater Funct Mater ; 18: 2280800020930180, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32946316

RESUMO

Fiber-reinforced polyester composites have received significant attention in a variety of applications due to their considerable potential due to such characteristics as high strength, stiffness, and modulus. However, one of the most important concerns about polymeric composites is their sensitivity to moisture attack. This work has been conducted to investigate the effects of nanoclay addition on reinforcing glass/polyester composites against water absorption and the resultant deterioration of flexural strength. Therefore, chopped strand mat and woven fiberglass polyester specimens were fabricated by using the hand lay-up technique with varying weight percentages of Cloisite 20A nanoclays (0, 1.5, and 3 wt%) and immersion in water for a time duration of 21 days. The specimens were weighed for the water absorption test. The results showed a remarkable drop in water absorption of the composite samples with the increase of nanoclay content. Moreover, although all the pure and nanocomposite specimens underwent degradation in flexural strength due to the water absorption, the strength was found to significantly increase with increasing the percentage of nanoclay at all immersion periods. The experimental results were confirmed by scanning electron microscopy (SEM). SEM images indicated that the presence of nanoclay protected the fiber/matrix interfaces.

3.
J Esthet Restor Dent ; 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32959520

RESUMO

PURPOSE: To compare the shade matching capabilities between an intraoral scanner (IOS) and a spectrophotometer under different ambient light illuminance conditions. MATERIAL AND METHODS: The shade of three teeth of a patient was obtained using an IOS (IOS group) (TRIOS 3; 3Shape) and a spectrophotometer (DS group) (EasyShade V; Vita Zahnfabrik) at 4 ambient illuminances: 10000-, 1000-, 500-, and 0-lx. Ten shade measurements were documented using Vita Classical and 3D-Master guides per tooth at each lighting condition. Data was analyzed using the Kruskal-Wallis and Mann Whitney U tests (α = .05). RESULTS: Significant shade discrepancies were obtained between the groups in different lighting conditions (P < .05). The IOS group presented significant shade discrepancies in different lighting conditions when evaluated using either shade guide, with lower variation under the 0-lx condition. However, the DS group did not present significant shade discrepancies among the different lighting conditions with either shade guide, except for the maxillary lateral incisor measured under 10 000-lx condition using the 3D-Master guide. CONCLUSIONS: Lighting conditions influenced the shade matching competency of an IOS. The IOS tested obtained high variation in the different lighting conditions evaluated and provided a lower shade value than the spectrophotometer. The spectrophotometer revealed high consistency amongst the various lighting conditions evaluated. CLINICAL IMPLICATIONS: Ambient light illuminance conditions can impact the shade matching capabilities of IOSs. The results of this investigation suggest the use of a supplementary instrumental method for assessment of tooth shade.

4.
J Prosthodont ; 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32864812

RESUMO

PURPOSE: To evaluate the color stability of CAD/CAM complete denture resins. MATERIALS AND METHODS: A total of 176 resin specimens were manufactured from conventional heat-polymerizing (pink: CONHCP : n = 16; tooth-shade: CONHCT : n = 16), CAD/CAM subtractively manufactured (pink: WIMP : n = 16, AVMP : n = 16, MEMP : n = 16, POMP : n = 16; tooth-shade: AVMT : n = 16, MEMT : n = 16, POMT : n = 16), and additively manufactured (pink: NDRPP : n = 16; tooth-shade: NDRPT : n = 16) denture resins; four different aging processes (thermal cycling, distilled water, red-wine, and coffee) were used. A spectrophotometer evaluated the color change (ΔE) using two modes of measurements (specular component included (ΔESCI ) and specular component excluded (ΔESCE )) recorded at baseline (T0 ) and at day#30 (T30 ). ANOVA and post hoc tests were used for statistical analysis (alpha = 0.05). RESULTS: Additively manufactured resins (NDRPP and NDRPT ) demonstrated significant ΔE in comparison to the other groups in all aging media (p < 0.001). WIMP demonstrated higher ΔESCI in comparison to the other subtractively manufactured groups in distilled water (p < 0.001). In red-wine, AVMT revealed significantly more ΔESCE than POMT (p = 0.039). In coffee, the ΔESCE was higher for CONHCT than MEMT (p = 0.026) and POMT (p = 0.011). Similarly, in coffee the ΔESCE for AVMT was higher than POMT (p = 0.030). CONCLUSION: Additively manufactured denture resins demonstrated the maximum color change compared to conventional heat-polymerized and CAD/CAM subtractively manufactured denture resins. Furthermore, CAD/CAM subtractively manufactured denture resins were not inferior to conventional resins in terms of color stability.

5.
Clin Exp Dent Res ; 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32902165

RESUMO

OBJECTIVES: Creating a tooth-like appearance by use of dental ceramics is still a challenge. Opalescence is a unique property of dental enamel, attempted to be mimicked by dental restorative materials. This study aimed to assess the effect of ceramic thickness on opalescence. MATERIALS AND METHODS: Twenty-four discs were fabricated of feldspathic ceramic, IPS e.max, zirconia and Enamic ceramics with 10 mm diameter and 0.5 and 1 mm thicknesses (n = 12). The opalescence of ceramic specimens was calculated by measuring the difference in yellow-blue axis (CIE ∆b*) and red-green axis (CIE ∆a*) between the transmitted and reflected spectra. One-way ANOVA was applied to compare the opalescence of different ceramic specimens with variable thicknesses at .05 level of significance. RESULTS: The opalescence of feldspathic, IPS e.max, zirconia and Enamic ceramic specimens with 0.5 mm thickness was 1.06 ± 0.15, 3.39 ± 0.15, 1.98 ± 0.15 and 1.44 ± 0.15, respectively. By increasing the thickness to 1 mm, the opalescence of feldspathic, IPS e.max, zirconia and Enamic ceramics changed to 1.12 ± 0.15, 1.47 ± 0.15, 3.85 ± 0.15 and 2.00 ± 0.15, respectively. In all groups except for IPS e.max, the mean opalescence of 1-mm-thick specimens was higher than that of 0.5-mm-thick specimens. CONCLUSION: Type and thickness of ceramic affect its opalescence. The opalescence of all ceramic specimens tested in this study with 0.5 and 1 mm thicknesses was lower than that of the enamel.

6.
J Appl Biomater Funct Mater ; 18: 2280800020926615, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941094

RESUMO

OBJECTIVE: To evaluate the effects of surface treatment and repair material on the repair shear bond strength (SBS) of the bioactive restorative material. METHODS: A total of 240 Activa BioActive Restorative (Activa) discs were prepared, aged, and polished, and divided randomly into eight groups (n = 30). Groups 1-4 discs were repaired with bulk-fill flowable resin-based composite (Bulk-RBC), and Groups 5-8 discs with Activa. Surface treatment used for each repair material type were air abrasion with silica-coated 30-m Al2O3 particles (air abrasion) (Groups 2 & 6), Air abrasion with universal primer (Groups 3 & 7), and Air abrasion with universal adhesive (Groups 4 & 8). Groups 1 and 5 were controls without surface treatment. SBS test was performed, and the failure mode and surface topography were assessed. RESULTS: Surface treatment with air abrasion significantly improved the SBS for repair using both Activa and Bulk-RBC. Repair SBS using Activa was significantly higher compared with Bulk-RBC. Cohesive failure in substrate and mixed failures were most common in the surface-treated groups (2-4, 6-8). Air abrasion produced prominent surface topography changes compared with polishing. CONCLUSION: Air abrasion enhances the repair SBS of aged bioactive restorative material. The use of the same material (Activa) for repair affords a higher bond strength compared with the use bulk-RBC.

7.
J Prosthodont Res ; 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32938878

RESUMO

PURPOSE: Polymers are used in dentistry on a daily basis due to their mechanical, functional and aesthetic properties. However, such biomaterials are subject to deterioration in the oral environment. Thus, this study aimed to evaluate the structural properties of five commonly used dental polymers to determine their best clinical indications. METHODS: Four hundred-fifty samples of five dental polymers (polyethylenterephthalat - glycol modified (PG), polymethyl methacrylate (PA), ethylene vinyl acetate(E), polycarbonate (PC), polyetheretherketone (PK) were prepared to investigate their thermal, structural and chemical characteristics using energy dispersive spectroscopy (EDS), Fourier transform infrared analysis(FTIR), scanning electron microscopy (SEM), differential scanning calorimetry(DSC), thermogravimetric analysis(TGA), X-ray diffraction(XRD), and Shore D hardness test. Data were analyzed using one-way ANOVA, Tukey's HSD, and Levene's tests (α=0.05). RESULTS: PK (87.2) and PA (82.4) displayed the highest hardness values and smooth surfaces, as observed with SEM (p<0.001). Silica was detected in PK, PA, and E by EDS and XRD. The highest glass transition temperature was recorded for PC (145.00±2.00°C) and PK (143.00±1.87°C), while the lowest value was measured for E (50.00±2.12°C)(p<0.001).The highest mass loss was detected for PG (91.40±1.40%) by TGA. CONCLUSIONS: PA and PK polymers can be used for stress-containing treatments due to their mechanical properties. These two materials are also advantageous in terms of plaque accumulation as these polymers reveal smoother surfaces than other groups. Insufficient physical and thermal properties require the use of E with caution and only in limited clinical indications.

8.
Cranio ; : 1-11, 2020 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-32893748

RESUMO

OBJECTIVE: To investigate the effect of aromatherapy massage on pain intensity and maximal mouth opening (MMO) in patients with myogenous TMD. METHODS: Ninety-one patients were randomly assigned to three groups: Group L (aromatherapy massage with lavender oil, test), group P (massage with sweet almond oil, placebo), and group C (control). Participants were evaluated at T0 (before the intervention), T1 (immediately after the intervention), and T2 (2-month follow-up). Data were analyzed using one-way ANOVA, Tukey's HSD, and Kruskal-Wallis tests. RESULTS: For T1 and T2, group L showed the greatest MMO values (48.01 ± 0.85 mm; 45.67 ± 0.84 mm), while group C exhibited the lowest values (39.13 ± 0.49 mm; 39.66 ± 0.82 mm) (p < 0.001). For VAS, group L revealed the lowest pain values at T1 (2) and T2 (2) (p < 0.001). DISCUSSION: Aromatherapy massage with lavender oil was effective in the management of painful TMD conditions and limited mouth opening.

9.
J Mech Behav Biomed Mater ; 110: 103892, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32778529

RESUMO

AIM: Bioceramic-containing root canal sealers are the most recently introduced sealers in endodontics. The present work reported experiments on a bioceramic-based root canal sealer with the objective of improving its physiochemical properties via reinforcement with each one of the three different nanomaterials: multi-walled carbon nanotubes (MWCNTS), titanium carbide (TC) or boron nitride (BN) in two weight percentages (1 wt% and 2 wt%). METHODOLOGY: Each nanomaterial was added to a definite weight of BioRoot root canal sealer (BioRoot™ RCS, Septodont, Saint-Maur-des-Fossés, France). Three composite groups of each weight percentage were prepared for evaluation: BioRoot/MWCNTS, BioRoot/TC and BioRoot/BN. The initial and final setting times, solubility, elution and pH values of the freshly-mixed and set samples were evaluated and compared to pristine BioRoot™ RCS. Setting times were evaluated using Gilmore needles. Solubility and elution were determined after immersion in water for 24 h. Scanning electron microscopy was used to examine the microstructure of the composite materials. RESULTS: The 1-wt. % composites possessed significantly shorter initial and final setting times compared with the pristine BioRoot™ RCS (p < 0.05). The 2-wt.% composites exhibited longer initial setting times but significantly shorter final setting times than BioRoot RCS (p < 0.05). Most of the composites had relatively lower solubility and elution profiles, with BioRoot/1-wt.% TC and BioRoot/1-wt.% BN being the lowest (p < 0.05). BioRoot™ RCS and all composites exhibited an alkaline pH profile over a period of 4 weeks and a significantly higher alkaline pH (p < 0.05) was recorded for BioRoot/1-wt.% and Bioroot/2-wt.% TC. CONCLUSIONS: A bioceramic-containing root canal sealer (BioRootTM RCS) with a shorter setting time, an alkaline pH profile, and a relatively lower solubility may be developed by incorporation of nanomaterials.

10.
Int J Comput Dent ; 23(3): 225-233, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32789310

RESUMO

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.


Assuntos
Porcelana Dentária , Falha de Restauração Dentária , Cerâmica , Desenho Assistido por Computador , Coroas , Planejamento de Prótese Dentária , Análise do Estresse Dentário , Humanos , Teste de Materiais , Impressão Tridimensional
11.
Clin Oral Investig ; 2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32785851

RESUMO

OBJECTIVES: To evaluate the clinical performance of partial glass-ceramic (IPS e.max Press) posterior restorations. MATERIALS AND METHODS: A total of 765 restorations in 158 patients were placed between 2008 and 2018 and evaluated in a prospective study during regular dental care visits between 2015 and 2018. The restorations were luted with a conventional photo-polymerized resin composite (HFO) in conjunction with an Immediate Dentin Sealing procedure (IDS). Intra-oral photographs and radiographs were made and evaluated using USPHS criteria. RESULTS: The mean observation time was 53.3 months (range 3-113 months). Three absolute failures occurred (tooth fractures, n = 2; apical re-infection, n = 1) all leading to the loss of the restored tooth. Repairable and salvageable failures occurred in 9 teeth (endodontic complications, n = 7; secondary caries, n = 1; debonding, n = 1). The survival and success rates according to Kaplan-Meier after 5 years cumulated to 99.6% and 98.6%, respectively. Location (premolar/molar and mandibula/maxilla), pre-restorative endodontic status (vital/devitalised) and extension of the indirect ceramic restoration (number of sides and cusps involved) did not significantly affect the cumulative success rate (log rank test, p > 0.05). The condition of the vast majority of the restorations remained unaffected for 5 years. CONCLUSIONS: Partial glass-ceramic posterior restorations (pressed lithium disilicate (IPS e.max press, Ivoclar Vivadent) luted by means of a conventional photo-polymerized resin composite in conjunction with the use of an IDS procedure have an excellent medium-term prognosis. CLINICAL RELEVANCE: Partial glass-ceramic posterior restorations can be considered as a highly reliable treatment option. Location and extension of the restoration and pre-restorative endodontic status do not affect success rate.

12.
Minerva Stomatol ; 69(3): 148-152, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32610723

RESUMO

BACKGROUND: To compare the image quality of two different digital imaging systems; one photostimulable phosphor plate system (PSP) and a direct digital radiography system with CMOS imaging sensor; via evaluating contrast resolution among four different exposure times. METHODS: Endodontically treated incisor teeth embedded in paraffin blocks are aligned next to a 99.5% Al wedge and exposed for 0.8, 0.1,0.125 and 0.16 seconds using both the CMOS and PSP systems. Using ImageJ software, 5 isometric and isogridded ROI from each root filling area and isometric ROI from the Al stepwedge were calculated. RESULTS: Evaluation of the total of 120 images displayed that PSP system produced significantly higher contrast resolution (P<0.05) in regard to pixel values than the CMOS. The CMOS system was non- responsive to increasing dose (P=0.000). Regarding the EqAl values, no significant difference was determined between groups (P>0.05). CONCLUSIONS: The contrast resolution was higher using the PSP system. It can be estimated that, filling material will be more obvious under lower doses using PSP.


Assuntos
Radiografia Dentária Digital
13.
Eur J Dent ; 2020 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-32645732

RESUMO

OBJECTIVE: The aim of this study was to assess the impact of implant platform diameters on ultimate force to failure of zirconia abutments with different angulation. MATERIALS AND METHODS: Forty-two zirconia abutments with either 0 degree (ST) or 15-degree (AN) angulation were assembled on tapered internal connection titanium implants (Direct's Legacy; 13 mm Implant Direct, LLC, Las Vegas, United States) with a platform diameter of Ø3.0, Ø3.5, and Ø4.5 mm (14 per group). Zirconia crowns (Ceramill Zolid; Amann Girrbach GmbH) were fabricated and cemented using self-adhesive resin cement (MaxCem Elite, Kerr). The specimens were thermomechanically loaded (TCML= 6,000 cycles of 5 to 50°C for 2 minutes/cycle followed by cyclic loading 600,000 cycles) followed by static loading until fracture. The data of load (N) at which fracture occurred were statistically analyzed by using Kruskal-Wallis analysis of variance and Mann-Whitney U tests at 5% significance level. RESULTS: Higher load to fracture was reported for zirconia crowns in straight abutments groups and a platform of 4.5, 3.5, and 3 mm diameter was 438.2± 85.4, 345.5± 71.3, and 331.1± 59.1 N, respectively. However, the groups restored with zirconia crowns in angulated abutments groups and a platform of 4.5, 3.5, or 3 mm diameter showed a fracture load of 411.4 ± 49.8, 354.2 ± 52.5, and 302.8 ± 52.5 N, respectively. CONCLUSION: Straight and angulated zirconia abutments presented similar load to fracture on 3 and 3.5 mm platform diameters yet being significantly less for 4.5 mm diameter.

14.
Braz Dent J ; 31(3): 272-280, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32667522

RESUMO

The purpose of this study was to evaluate the influence of the application mode of three universal adhesive systems on interfacial physical properties of indirect composite restorations adhesively cemented to dentin cavities. Seventy-eight bovine lower incisors were selected and a slice of dentin (thickness: 2 mm) between the buccal surface and pulp chamber was obtained for each tooth. Conical cavities were made on this surface. The internal walls of the cavities were then coated with a hydrophilic gel, filled with composite resin and photopolymerized. The dentin/cone sets were divided into 6 groups (n=10) according to type of universal adhesive (TETRI: Tetric N Bond, FUT: Futura Bond U, SBU: Single Bond Universal) and acid etching on dentin (A: with acid etching; WA: without acid etching). The acid etching and the adhesive systems were applied to the surface of the dentin. All composite resin cones were sandblasted (Al2O3, 20 s) and silanized. After surface treatment, the cones were cemented (RelyX Ultimate) into the dentin cavity and photopolymerized. After thermocycling (10,000 cycles), samples were submitted to marginal adaptation analysis (using caries detector dye), push-out test (0.5 mm/min), and failure mode analysis. Additional samples were prepared for nanoleakage analysis (SEM). The data (MPa) were analyzed by two-way ANOVA and Tukey's post-test (5%). The groups in which the dentin was acid etched showed significantly lower bond strength values in the push-out test (p<0.01). Dentin acid etching significantly reduced the bond strength between universal adhesive systems and dentin in indirect restorative procedures.


Assuntos
Colagem Dentária , Adesivos Dentinários , Animais , Bovinos , Resinas Compostas , Cimentos Dentários , Cavidade Pulpar , Dentina , Teste de Materiais , Cimentos de Resina , Propriedades de Superfície , Resistência à Tração
15.
J Prosthet Dent ; 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32694021

RESUMO

STATEMENT OF PROBLEM: Materials possessing fluorescent properties are assumed to emit sufficient visible light to change tooth color under daylight illumination. Fluorescent and nonfluorescent glaze pastes are available to finish the surface of a pressed lithium disilicate restoration. However, the effect of a fluorescent-glaze layer on the final color of the restoration remains unclear. PURPOSE: The purpose of this in vitro study was to measure the color dimensions of lithium disilicate glass ceramic with different thicknesses and different surface treatments under daylight (D65) illumination conditions. MATERIAL AND METHODS: A total of 120 pressed lithium disilicate glass ceramic disks were fabricated with 4 different thicknesses: 0.7, 1.2, 1.7, and 2.2 mm. In each thickness, 3 different subgroups were created based on the surface treatment performed (n=10): polished (NG), clear glaze (CG), and fluorescent glaze (FG). For the NG group, disks were polished with 180-, 320-, 600-, 800-, and 1400-grit SiC papers and a polishing machine. For the glazed groups, the CG and FG groups, the specimens were polished with 180-grit SiC papers and the same polishing machine. After the polishing sequence, the final thickness was verified in all groups by using digital calipers (0.5, 1.0, 1.5, and 2.0 mm). Additionally, 20 µL of clear glaze or fluorescent glaze was applied on the CG and FL groups by using an electronic positive displacement repeating pipette. The glaze layer was crystallized in a furnace according to the manufacturer recommendations. Color measurements in the CIELab coordinates were made with a spectrometer coupled to an integrating sphere and a standardized photography gray card as a background. Color difference (ΔE) values were calculated by using the CIE76 and CIEDE2000 formulas. The Shapiro-Wilk test revealed that the data were normally distributed. Two-way ANOVA and the Bonferroni test for multiple comparisons were used to analyze the data (α=.05). RESULTS: Statistically significant differences were found among the groups for the L∗, a∗, and b∗ values for the different ceramic thicknesses and surface finishing treatments evaluated (P<.001), except for the b∗ value between the FG and CG groups (P=.988). The L∗ value on the polished group was significantly higher than that on the glazed specimens, followed by the fluorescent-glazed and then by the clear-glazed specimens (P<.001). The ΔE values using the CIE76 formula varied from 0.87 to 2.76 among specimen groups and from 0.32 to 2.34 using the CIEDE2000 among the tested groups. CONCLUSIONS: Ceramic thickness and surface finishing treatment affected all color dimensions (L∗, a∗, and b∗ values) of lithium disilicate ceramic under daylight conditions. These differences resulted in a perceptible but acceptable color mismatch. The value (L∗ color dimension) of the lithium disilicate ceramic was higher on fluorescent-glazed than on not-fluorescent-glazed specimens.

16.
J Adhes Dent ; 22(4): 343-351, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32666060

RESUMO

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).


Assuntos
Resinas Compostas , Adaptação Marginal Dentária , Restauração Dentária Permanente , Adulto , Dente Pré-Molar , Seguimentos , Humanos , Polimerização , Estados Unidos , United States Public Health Service
17.
Minerva Stomatol ; 2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32698563

RESUMO

BACKGROUND: This study evaluated the effect of different polymerization modes and duration on the degree of conversion (DC) of resin cement under different types of ceramics. METHODS: Ceramic materials were divided into 3 groups (n=60): Group 1; CERASMART, Group 2; Vita Enamic and Group 3; Vita MARK II. Each group was then divided into three subgroups (n=20) according to the polymerization mode (A; low-intensity, B; high-intensity, and C; soft-start). Subgroups were then divided into two further groups according to the polymerization time (I; 10 s and II; 20 s). DC of light-cured resin cement beneath different kinds of ceramics was tested using FTIR spectroscopy. Results were compared to a control group cured without overlying ceramic. RESULTS: While the type of ceramic and mode of polymerization showed a significant effect on the DC of resin cement, polymerization duration did not. Vita Mark II group showed significantly the highest DC of resin cement, followed by Vita Enamic and Cerasmart. High and low intensity polymerization modes did not show significant difference but both showed significantly lower DC when compared to soft start mode. CONCLUSIONS: Type of ceramic and polymerization mode showed a direct effect on the DC of resin cement.

18.
J Mech Behav Biomed Mater ; 109: 103855, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32543415

RESUMO

PURPOSE: The objectives of this study were to evaluate the load bearing capacity of RBFDPs made of different materials after cyclic loading, and classify the failure types after loading. MATERIALS AND METHODS: Sound human mandibular first premolars and first molar pairs (N = 60 per tooth type, n = 10 per group) were randomly divided into six experimental groups to receive one of the following inlay-retained RBFDP types: RC: Resin composite only, DFRC: Direct E-glass fiber-reinforced composite (FRC), IFRC: Indirect E-glass FRC, LS: Lithium disilicate glass-ceramic, ZR: Yttria-stabilized tetragonal zirconia, MC: Metal-ceramic. Box preparations were made in abutment teeth using diamond burs followed by standardized ultrasonic burs. The teeth were conditioned employing an etch-and-rinse adhesive system and the indirect RBFDPs were cemented adhesively. The specimens were subjected to cyclic loading for x1.200.000 in distilled water alternating between 5 and 55 °C (Zurich Chewing Simulator). They were then loaded to failure from the occlusal surface in the Universal Testing Machine (cross-head speed: 1 mm/min). Failure types were classified as repairable or irreparable depending on the location and size. Data were analyzed using Welch and Tamhane's T2 post-hoc tests (α = 0.05). Weibull modulus for each group was calculated based on parametric distribution analysis of censored data for maximum fracture load. RESULTS: Mean load bearing capacity (N) of Groups LS (1274 ± 270), ZR (1567 ± 363) and MC (1544 ± 787) were significantly higher than those of other groups (p < 0.05). RC, DFRC, IFRC (601 ± 130 - 819 ± 270) and MC did not show significant difference (p > 0.05). Weibull modulus (m) was the highest in Group LS (m = 5.3) followed by Group RC (m = 5.1). Other groups presented Weibull moduli ranging between 1.4 and 3.3. Only in Group ZR, 2 early debonding occurred during cyclic loading. While in this group predominantly irreparable failures (debonding with without tooth fracture) were observed (8 out of 10), all other groups presented mainly single or a combination of repairable failures (chipping in the veneering material). DFRC, IDRC and MC did not show any debonding from the abutment teeth. CONCLUSION: Considering load bearing capacity, repairable failure types and Weibull moduli, lithium disilicate seem to be more durable than those of other material options for posterior inlay-retained RBFDPs. Due to early debondings and catastrophic irreparable failure types, zirconia RBFDPs should be indicated with caution in the posterior region.

19.
J Oral Sci ; 62(3): 288-292, 2020 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-32475863

RESUMO

The purpose of this study was to determine the depth of cure and the type and amount of monomers released from bulk-fill composites in different curing protocols. Five different composite resins Filtek Bulk-Fill Posterior, Filtek Bulk-Fill Flowable, SureFil SDR, X-tra Fil, and X-tra base, were used. A light-emitting diode (LED) device was used in 3 different modes (standard, high power, and extra power mode), and a halogen light device was also used as a control. Surface hardness was measured and the depth of cure was calculated. Monomer analysis was performed using high performance liquid chromatography (HPLC). The data were analyzed using Tamhane's T2 post-hoc test (α = 0.05). The cure depth for all materials except for Filtek Bulk-Fill Posterior (extra power mode) and Filtek Bulk-Fill Flowable (high power and extra power modes) was over 80%. Under the conditions of this study, the amount of monomer released from composite resins changed according to the type of composite resin and the light mode used.


Assuntos
Resinas Compostas , Materiais Dentários , Dureza , Teste de Materiais , Polimerização , Propriedades de Superfície
20.
J Prosthodont ; 2020 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-32548890

RESUMO

PURPOSE: To review the primary additive manufacturing (AM) technologies used to fabricate metals in implant dentistry and compare them to conventional casting and subtractive methods. METHODS: The literature on metal AM technologies was reviewed, and the AM procedures and their current applications in implant dentistry were collated and described. Collection of published articles about metal AM in dental field data sources: MEDLINE, EMBASE, EBSCO, and Web of Science searched. All studies related to AM technology description, analysis, and evaluation of applications in implant dentistry, including AM titanium (Ti) dental implants, customized Ti mesh for bone grafting techniques, cobalt-chromium (Co-Cr) frameworks for implant impression procedures, and Co-Cr and Ti frameworks for dental implant-supported prostheses were reviewed. RESULTS: Literature has demonstrated the potential of AM technologies to fabricate dental implants, root-analog implants, and functionally graded implants; as well as the ability to fabricate customized meshes for bone grafting procedures. Metal AM technologies provide a reliable method to manufacture frameworks for implant impression procedures. Co-Cr and Ti AM frameworks for implant-supported prostheses provide a clinically acceptable discrepancy at the implant-prostheses interface. CONCLUSIONS: Additional clinical studies are required to assess the long-term clinical performance, biological and mechanical complications, and prosthetic restoration capabilities of additively manufactured dental implants. Moreover, further studies are needed to evaluate their long-term success and survival rates and biological and mechanical complications of AM implant-supported prostheses.

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