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1.
Stephano Zerlottini ISAAC Ana Claudia Pietrobom BERGAMIN Cecília Pedroso TURSSI Flávia Lucisano Botelho do AMARAL Roberta Tarkany BASTING Fabiana Mantovani Gomes FRAN?A 《Journal of applied oral science : revista FOB》2013,21(5):452-459
Objective
The aim of this in vitro study was to evaluate the microtensile bond strength (µTBS) to dentin of two different restorative systems: silorane-based (P90), and methacrylate-based (P60), using two cavity models.Material and Methods
Occlusal enamel of 40 human third molars was removed to expose flat dentin surface. Class I cavities with 4 mm mesial-distal width, 3 mm buccal-lingual width and 3 mm depth (C-factor=4.5) were prepared in 20 teeth, which were divided into two groups (n=10) restored with P60 and P90, bulk-filled after dentin treatment according to manufacturer''s instructions. Flat buccal dentin surfaces were prepared in the 20 remaining teeth (C-factor=0.2) and restored with resin blocks measuring 4x3x3 mm using the two restorative systems (n=10). The teeth were sectioned into samples with area between 0.85 and 1.25 mm2 that were submitted to µTBS testing, using a universal testing machine (EMIC) at speed of 0.5 mm/min. Fractured specimens were analyzed under stereomicroscope and categorized according to fracture pattern. Data were analyzed using ANOVA and Tukey Kramer tests.Results
For flat surfaces, P60 obtained higher bond strength values compared with P90. However, for Class I cavities, P60 showed significant reduction in bond strength (p<0.05). No statistical difference between restorative systems was shown for Class I cavity model (p>0.05), or between Class I Cavity and Flat Surface group, considering P90 restorative system (p>0.05). Regarding fracture pattern, there was no statistical difference among groups (p=0.0713) and 56.3% of the fractures were adhesive.Conclusion
It was concluded that methacrylate-based composite µTBS was influenced by cavity models, and the use of silorane-based composite led to similar bond strength values compared to the methacrylate-based composite in cavities with high C-factor. 相似文献2.
SS Jalandar DS Pandharinath K Arun V Smita 《The journal of advanced prosthodontics》2012,4(3):127-133
PURPOSE
Many dentists use desensitizing agents to prevent hypersensitivity. This study compared and evaluated the effect of two desensitizing agents on the retention of cast crowns when cemented with various luting agents.MATERIALS AND METHODS
Ninety freshly extracted human molars were prepared with flat occlusal surface, 6 degree taper and approximately 4 mm axial length. The prepared specimens were divided into 3 groups and each group is further divided into 3 subgroups. Desensitizing agents used were GC Tooth Mousse and GLUMA® desensitizer. Cementing agents used were zinc phosphate, glass ionomer and resin modified glass ionomer cement. Individual crowns with loop were made from base metal alloy. Desensitizing agents were applied before cementation of crowns except for control group. Under tensional force the crowns were removed using an automated universal testing machine. Statistical analysis included one-way ANOVA followed by Turkey-Kramer post hoc test at a preset alpha of 0.05.RESULTS
Resin modified glass ionomer cement exhibited the highest retentive strength and all dentin treatments resulted in significantly different retentive values (In Kg.): GLUMA (49.02 ± 3.32) > Control (48.61 ± 3.54) > Tooth mousse (48.34 ± 2.94). Retentive strength for glass ionomer cement were GLUMA (41.14 ± 2.42) > Tooth mousse (40.32 ± 3.89) > Control (39.09 ± 2.80). For zinc phosphate cement the retentive strength were lowest GLUMA (27.92 ± 3.20) > Control (27.69 ± 3.39) > Tooth mousse (25.27 ± 4.60).CONCLUSION
The use of GLUMA® desensitizer has no effect on crown retention. GC Tooth Mousse does not affect the retentive ability of glass ionomer and resin modified glass ionomer cement, but it decreases the retentive ability of zinc phosphate cement. 相似文献3.
Ishihata H Finger WJ Kanehira M Shimauchi H Komatsu M 《Journal of applied oral science : revista FOB》2011,19(2):147-153
Objectives
To assess and to compare the effects of Gluma® Desensitizer (GDL) with an experimental glutaraldehyde and HEMA containing fumed silica dispersion (GDG) on dentin permeability using a chemiluminous tracer penetration test.Material and Methods
Twenty disc-shaped dentin specimens were dissected from extracted human third molars. The dentin specimens were mounted in a split chamber device for determination of permeability under liquid pressure using a photochemical method. Ten specimens were randomly selected and allocated to the evaluation groups Gluma® Desensitizer as aqueous solution and glutaraldehyde/HEMA as fumed silica dispersion, respectively. Dentin disc permeability was determined at two pressure levels after removal of smear with EDTA, after albumin soaking, and after application of the desensitizing agents. Two desensitizer-treated and rinsed specimens of each group were examined by scanning electron microscopy (SEM) for surface remnants.Results
Comparatively large standard deviations of the mean EDTA reference and albumin soaked samples permeability values reflected the differences of the dentin substrates. The mean chemiluminescence values of specimen treated with GDL and GDG, respectively, were significantly reduced after topical application of the desensitizing agents on albumin-soaked dentin. The effects of GDL and GDG on permeability were not significantly different. Treated specimens showed no surface remnants after rinsing.Conclusions
The experimental desensitizer gel formulation reduced dentin permeability as effectively as the original Gluma® Desensitizer solution. 相似文献4.
Carolina de Andrade Lima Chaves Renata Marques de Melo Sheila Pestana Passos Fernanda Pelógia Camargo Marco Antonio Bottino Ivan Balducci 《Journal of applied oral science : revista FOB》2009,17(3):155-160
Objectives:
To evaluate the microtensile bond strength (μTBS) of one- (Xeno III, Dentsply) and two-step (Tyrian-One Step Plus, Bisco) self-etching adhesive systems bonded to dentin and cemented to chemically cured (C&B Metabond) or light-cured paste of a dual-cure resin cement (Variolink II, Ivoclar) within a short (24 h) and long period of evaluation (90 days).Material and Methods:
Forty recently extracted human molars had their roots removed and their occlusal dentin exposed and ground wet with 600-grit SiC paper. After application of one of the adhesives, the resin cement was applied to the bonded surface and a composite resin block was incrementally built up to a height of 5 mm (n=10). The restored teeth were stored in distilled water at 37°C for 7 days. The teeth were then cut along two axes (x and y), producing beam-shaped specimens with 0.8 mm2 cross-sectional area, which were subjected to μTBS testing at a crosshead speed of 0.05 mm/min and stressed to failure after 24 h or 90 days of storage in water. The μTBS data in MPa were subjected to three-way analysis of variance and Tukey''s test (α= 0.05).Results:
The interaction effect for all three factors was statistically significant (three-way ANOVA, p<0.001). All eight experimental means (MPa) were compared by the Tukey''s test (p<0.05) and the following results were obtained: Tyrian-One Step Plus/C&B/24 h (22.4±7.3); Tyrian-One Step Plus/Variolink II/24 h (39.4±11.6); Xeno III/C&B/24 h (40.3±12.9); Xeno III/Variolink II/24 h (25.8±10.5); Tyrian-One Step Plus/C&B/90 d (22.1±12.8) Tyrian-One Step Plus/VariolinkII/90 d (24.2±14.2); Xeno III/C&B/90 d (27.0±13.5); Xeno III/Variolink II/ 90 d (33.0±8.9).Conclusions:
Xeno III/Variolink II was the luting agent/adhesive combination that provided the most promising bond strength after 90 days of storage in water. 相似文献5.
PURPOSE
Post surface conditioning is necessary to expose the glass fibers to enable bonding between fiber post and resin cement. The purpose of the present study was to evaluate the effect of different surface conditioning on tensile bond strength (TBS) of a glass fiber reinforced post to resin cement.MATERIALS AND METHODS
In this in vitro study, 40 extracted single canal central incisors were endodontically treated and post spaces were prepared. The teeth were divided into four groups according to the methods of post surface treatment (n=10): 1) Silanization after etching with 20% H2O2, 2) Silanization after airborne-particle abrasion, 3) Silanization, and 4) No conditioning (Control). Adhesive resin cement (Panavia F 2.0) was used for cementation of the fiber posts to the root canal dentin. Three slices of 3 mm thick were obtained from each root. A universal testing machine was used with a cross-head speed of 1 mm/minute for performing the push-out tests. Two-way ANOVA and Tukey post hoc tests were used for analyzing data (α=0.05).RESULTS
It is revealed that different surface treatments and root dentin regions had significant effects on TBS, but the interaction between surface treatments and root canal regions had no significant effect on TBS. There was significant difference among H2O2 + Silane Group and other three groups.CONCLUSION
There were significant differences among the mean TBS values of different surface treatments. Application of hydrogen peroxide before silanization increased the bond strength between resin cements and fiber posts. The mean TBS mean values was significantly greater in the coronal region of root canal than the middle and apical thirds. 相似文献6.
Kerem K?L?C Soley ARSLAN Goknil Alkan DEMETOGLU Gokmen ZARARSIZ Bulent KES?M 《Journal of applied oral science : revista FOB》2013,21(1):85-91
Objective:
The purpose of this study was to evaluate the effects of blood contamination and haemostatic agents such as Ankaferd Blood Stopper (ABS) and hydrogen peroxide (H2O2) on the microtensile bond strength between dual cured resin cement-dentin interface.Material and Methods:
Twelve pressed lithium disilicate glass ceramics were luted to flat occlusal dentin surfaces with Panavia F under the following conditions: Control Group: no contamination, Group Blood: blood contamination, Group ABS: ABS contamination Group H2O2: H2O2 contamination. The specimens were sectioned to the beams and microtensile testing was carried out. Failure modes were classified under stereomicroscope. Two specimens were randomly selected from each group, and SEM analyses were performed.Results:
There were significant differences in microtensile bond strengths (µTBS) between the control and blood-contaminated groups (p<0.05), whereas there were no significant differences found between the control and the other groups (p>0.05).Conclusions:
Contamination by blood of dentin surface prior to bonding reduced the bond strength between resin cement and the dentin. Ankaferd Blood Stoper and H2O2 could be used safely as blood stopping agents during cementation of all-ceramics to dentin to prevent bond failure due to blood contamination. 相似文献7.
Effect of the application time of phosphoric acid and self-etch adhesive systems to sclerotic dentin
Alexandra Patricia MENA-SERRANO Eugenio Jose GARCIA Miguel Mu?oz PEREZ Gislaine Cristine MARTINS Rosa Helena Miranda GRANDE Alessandro Dourado LOGUERCIO Alessandra REIS 《Journal of applied oral science : revista FOB》2013,21(2):196-202
Objectives:
To evaluate the effect of application time on the resin-dentin bond strength (µTBS) and etching pattern of adhesive systems applied on sclerotic dentine.Material and Methods:
A total of forty-two bovine incisors had their roots removed. The 1-step self-etch GO (SDI), the 2-step self-etch Adper SE Bond (3MESPE) and the 35% phosphoric acid (3MESPE) from the 2-step etch-and-rinse Adper Single Bond 2 (3MESPE) were applied on the bovine incisal surfaces according to the manufacturer''s instructions or duplicating the recommended conditioning time. After adhesive application, thirty teeth were restored with composite resin, stored for 24 h in distilled water at 37º C, and sectioned into resin-dentin bonded sticks (0.8 mm2) and tested according to the µTBS at 0.5 mm/min. The etching pattern of the remaining twelve teeth (n=4 for each material) was examined under scanning electron microscopy. Each tooth was divided into a buccal-to-lingual direction into three thirds, and each third randomly assigned to the groups: control (no treatment), according to the manufacturers'' instructions and duplicating the recommended application time. The µTBS and the relative percentage of the tubule area opening were evaluated by two-way repeated measures ANOVA and Tukey''s tests (α=0.05).Results:
The duplication of the conditioning time favored only the GO adhesive (p<0.05). Both application methods significantly increased the tubule area opening (p<0.05) compared to the controls.Conclusions:
The efficacy of duplicating the conditioning time was only effective for the 1-step self-etch adhesive system tested. 相似文献8.
Duygu Sara? Safak Külünk Y. Sinasi Sara? ?zlem Karakas 《Journal of applied oral science : revista FOB》2009,17(5):495-500
Objective:
The objective of this study was to evaluate the effect of desensitizing agents containing different amounts of fluoride on the shear bond strength of a dual polymerized resin cement and a resin-modified glass ionomer cement (RMGIC) to dentin.Material and Methods:
One hundred human molars were mounted in acrylic resin blocks and prepared until the dentin surface was exposed. The specimens were treated with one of four desensitizing agents: Bifluorid 12, Fluoridin, Thermoline and PrepEze. The remaining 20 specimens served as untreated controls. All groups were further divided into 2 subgroups in which a dual polymerized resin cement (Bifix QM) or a resin-modified glass ionomer cement (AVANTO) was used. The shear bond strength (MPa) was measured using a universal testing machine at a 0.5 mm/min crosshead speed. The data were analyzed statistically with a 2-way ANOVA, Tukey HSD test and regression analysis (α=0.05). The effect of the desensitizing agents on the dentin surface was examined by scanning electron microscopy.Results:
The fluoride-containing desensitizing agents affected the bond strength of the resin-based cements to dentin (p<0.001). PrepEze showed the highest bond strength values in all groups (p<0.001).Conclusion:
Regression analysis showed a reverse relation between bond strength values of resin cements to dentin and the amount of fluoride in the desensitizing agent (p<0.05). 相似文献9.
Fernanda Brand?o MOLLICA Carlos Rocha Gomes TORRES Sergio Eduardo de Paiva GON?ALVES ?Maria Nadir Gasparoto MANCINI 《Journal of applied oral science : revista FOB》2012,20(4):449-454
There are several methods for identifying carious dentinal tissue aiming to avoid
removal of healthy dentinal tissue.
Objectives
The purpose of this study was to test different methods for the detection of carious dentinal tissue regarding the amount of carious tissue removed and the remaining dentin microhardness after caries removal.Material and methods
The dentin surfaces of 20 bovine teeth were exposed and half of the surface was protected with nail polish. Cariogenic challenge was performed by immersion in a demineralizing solution for 14 days. After transverse cross-section of the crown, the specimens were divided into four groups (n=10), according to the method used to identify and remove the carious tissue: "Papacárie", Caries-detector dye, DIAGNOdent and Tactile method. After caries removal, the cross-sectional surface was included in acrylic resin and polished. In a microhardness tester, the removed dentin thickness and the Vickers microhardness of the following regions were evaluated: remaining dentin after caries removal and superficial and deep healthy dentin.Results
ANOVA and Tukey''s test (α=0.05) were performed, except for DIAGNOdent, which did not detect the presence of caries. Results for removed dentin thickness were: "Papacárie" (424.7±105.0; a), Caries-detector dye (370.5±78.3; ab), Tactile method (322.8±51.5; bc). Results for the remaining dentin microhardness were: "Papacárie" (42.2±10.5; bc), Caries-detector dye (44.6±11.8; abc), Tactile method (24.3±9.0; d).Conclusions
DIAGNOdent did not detect the presence of carious tissue; Tactile method and "Papacárie" resulted in the least and the most dentinal thickness removal, respectively; Tactile method differed significantly from "Papacárie" and Caries-detector dye in terms of the remaining dentin microhardness, and Tactile method was the one which presented the lowest microhardness values. 相似文献10.
Doglas CECCHIN Ana Paula FARINA Daniel GALAFASSI Jo?o Vicente Baroni BARBIZAM Silmara Aparecida Milori CORONA Bruno CARLINI-JúNIOR 《Journal of applied oral science : revista FOB》2010,18(4):385-389
Chemical substances used during biomechanical preparation of root canals can alter
the composition of dentin surface and affect the interaction with restorative
materials.
Objective
The purpose of this study was to evaluate the microtensile bond strength (µTBS) of a self-etching adhesive system to dentin irrigated with sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (eDTA).Material and Methods
Thirty human third molars were sectioned 3 mm below the occlusal surface, polished with 600- to 1200-grit silicon carbide papers, and randomly divided into 3 groups: G1 (control): no irrigating solution; G2: 1% NaOCl; and G3: 1% NaOCl followed by the application of 17% eDTA. The specimens received the self-etching adhesive system (XeNO III - Dentsply), restored with microhybrid composite resin (Z250 - 3M ESPE), sectioned and trimmed to create 4 hourglass-shaped slabs of each tooth. The slabs were tested in microtensile strength in a universal testing machine (emic DL 2000) at a crosshead speed of 0.5 mm/min until fracture. The results were analyzed statistically by ANOVA and Newman-Keuls test.Results
Mean µTBS values and standard deviations in MPa were: G1 = 11.89 ± 4.22; G2 = 19.41 ± 5.32; G3 = 11.34 ± 4.73. 1% NaOCl increased the adhesive resistance significantly (p<0.001/ F=22.5763). The application of 1% NaOCl/17% eDTA resulted in statistically similar µTBS to the control group.Conclusions
None of the irrigants affected negatively the µTBS of XeNO III to dentin. The use of 1% NaOCl alone resulted in higher bond strength than the other treatments. The combination of 1% NaOCl and 17% eDTA produced similar bond strength to that of untreated dentin. 相似文献11.
Caroline COTES Mayra CARDOSO Renata Marques de MELO Luiz Felipe VALANDRO Marco Antonio BOTTINO 《Journal of applied oral science : revista FOB》2015,23(1):71-78
Objective
The purpose of this study was to assess the influence of conditioning methods and thermocycling on the bond strength between composite core and resin cement.Material and Methods
Eighty blocks (8×8×4 mm) were prepared with core build-up composite. The cementation surface was roughened with 120-grit carbide paper and the blocks were thermocycled (5,000 cycles, between 5°C and 55°C, with a 30 s dwell time in each bath). A layer of temporary luting agent was applied. After 24 h, the layer was removed, and the blocks were divided into five groups, according to surface treatment: (NT) No treatment (control); (SP) Grinding with 120-grit carbide paper; (AC) Etching with 37% phosphoric acid; (SC) Sandblasting with 30 mm SiO2 particles, silane application; (AO) Sandblasting with 50 mm Al2O3 particles, silane application. Two composite blocks were cemented to each other (n=8) and sectioned into sticks. Half of the specimens from each block were immediately tested for microtensile bond strength (µTBS), while the other half was subjected to storage for 6 months, thermocycling (12,000 cycles, between 5°C and 55°C, with a dwell time of 30 s in each bath) and µTBS test in a mechanical testing machine. Bond strength data were analyzed by repeated measures two-way ANOVA and Tukey test (α=0.05).Results
The µTBS was significantly affected by surface treatment (p=0.007) and thermocycling (p=0.000). Before aging, the SP group presented higher bond strength when compared to NT and AC groups, whereas all the other groups were statistically similar. After aging, all the groups were statistically similar. SP submitted to thermocycling showed lower bond strength than SP without thermocycling.Conclusion
Core composites should be roughened with a diamond bur before the luting process. Thermocycling tends to reduce the bond strength between composite and resin cement. 相似文献12.
Livia Picchi COMAR Cristiane de Almeida Baldini CARDOSO Senda CHARONE Larissa Tercilia GRIZZO Marília Afonso Rabelo BUZALAF Ana Carolina MAGALH?ES 《Journal of applied oral science : revista FOB》2015,23(1):14-18
Objective
This study assessed the effect of fluoride varnishes on the progression of tooth erosion in vitro. Material and Methods: Forty-eight enamel and 60 root dentin samples were previously demineralized (0.1% citric acid, pH 2.5, 30 min), leading to a baseline and erosive wear of 12.9 and 11.4 µm, respectively. The samples were randomly treated (6 h) with a 4% TiF4 varnish (2.45%F-, pH 1.0), a 5.42% NaF varnish (2.45%F-, pH 5.0), a placebo varnish and no varnish (control). The samples were then subjected to erosive pH cycles (4x90 s/day in 0.1% citric acid, intercalated with artificial saliva) for 5 days. The increment of the erosive tooth wear was calculated. In the case of dentin, this final measurement was done with and without the demineralized organic matrix (DOM). Enamel and dentin data were analyzed using ANOVA/Tukey’s and Kruskal-Wallis/Dunn tests, respectively (p<0.05).Results
The TiF4 (mean±s.d: 1.5±1.1 µm) and NaF (2.1±1.7 µm) varnishes significantly reduced enamel wear progression compared to the placebo varnish (3.9±1.1 µm) and control (4.5±0.9 µm). The same differences were found for dentin in the presence and absence of the DOM, respectively: TiF4 (average: 0.97/1.87 µm), NaF (1.03/2.13 µm), placebo varnish (3.53/4.47 µm) and control (3.53/4.36 µm).Conclusion
The TiF4 and NaF varnishes were equally effective in reducing the progression of tooth erosion in vitro. 相似文献13.
FRACTURE RESISTANCE OF WEAKENED TEETH RESTORED WITH CONDENSABLE RESIN WITH AND WITHOUT CUSP COVERAGE
Rafael Francisco Lia Mondelli Sérgio Kiyoshi Ishikiriama Otávio de Oliveira Filho José Mondelli 《Journal of applied oral science : revista FOB》2009,17(3):161-165
Objectives:
This in vitro study evaluated the fracture resistance of weakened human premolars (MOD cavity preparation and pulp chamber roof removal) restored with condensable resin composite with and without cusp coverage.Material and Methods:
Thirty human maxillary premolars were divided into three groups: Group A (control), sound teeth; Group B, wide MOD cavities prepared and the pulp chamber roof removed and restored with resin composite without cusp coverage; Group C, same as Group B with 2.0 mm of buccal and palatal cusps reduced and restored with the same resin. The teeth were included in metal rings with self-curing acrylic resin, stored in water for 24 h and thereafter subjected to a compressive axial load in a universal testing machine at 0.5 mm/min.Results:
The mean fracture resistance values ± standart deviation (kgf) were: group A: 151.40 ± 55.32, group B: 60.54 ± 12.61, group C: 141.90 ± 30.82. Statistically significant differences were found only between Group B and the other groups (p<0.05). The condensable resin restoration of weakened human premolars with cusp coverage significantly increased the fracture resistance of the teeth as compared to teeth restored without cusp coverage.Conclusion:
The results showed that cusp coverage with condensable resin might be a safe option for restoring weakened endodontically treated teeth. 相似文献14.
Fernanda de Carvalho Panzeri Pires-De-Souza Fabíola Fiorezi de Marco Luciana Assirati Casemiro Heitor Panzeri 《Journal of applied oral science : revista FOB》2007,15(2):120-126
Objective:
The aim of this study was to assess the bond strength of indirect composite restorations cemented with a resin-based cement associated with etch-and-rinse and self-etching primer adhesive systems to dentin treated or not with a bioactive material.Materials and Method:
Twenty bovine incisor crowns had the buccal enamel removed and the dentin ground flat. The teeth were assigned to 4 groups (n=5): Group I: acid etching + Prime & Bond NT (Dentsply); Group II: application of a bioactive glass (Biosilicato®)+ acid etching + Prime & Bond NT; Group III: One-up Bond F (J Morita); Group IV: Biosilicato® + One-up Bond F. Indirect composite resin (Artglass, Kulzer) cylinders (6x10mm) were fabricated and cemented to the teeth with a dualcure resin-based cement (Enforce, Dentsply). After cementation, the specimens were stored in artificial saliva at 37oC for 30 days and thereafter tested in tensile strength in a universal testing machine (EMIC) with 50 kgf load cell at a crosshead speed of 1 mm/min. Failure modes were assessed under scanning electron microscopy. Data were analyzed statistically by ANOVA and Tukey''s test (95% level of confidence).Results:
Groups I, II and III had statistically similar results (p>0.05). Group IV had statistically significant higher bond strength means (p<0.05) than the other groups. The analysis of the debonded surfaces showed a predominance of adhesive failure mode for Group III and mixed failure mode for the other groups.Conclusion:
The use of desensitizing agent did not affect negatively the bonding of the indirect composite restorations to dentin, independently of the tested adhesive systems. 相似文献15.
Denise Sá Maia CASSELLI André Luis FARIA-E-SILVA Henrique CASSELLI Luis Roberto Marcondes MARTINS 《Journal of applied oral science : revista FOB》2013,21(1):68-73
Objective:
This study evaluated the effect of the margin location and an adhesive system on the marginal adaptation of composite restorations.Material and Methods:
Class V cavities were prepared in bovine teeth with the gingival margin on the dentin and the incisal margin on the enamel. The cavities were restored with a micro-hybrid composite resin using an etch-and-rinse [Single Bond 2 (SB)] or a self-etching adhesive [Clearfil SE Bond (CL)]. After finishing and polishing the restorations, epoxy replicas were prepared. The marginal adaptation was analyzed using scanning electronic microscopy (SEM, 500 x magnification). The higher gap width in each margin was recorded (T0). After the first evaluation, the samples were submitted to thermal cycling (2,000 cycles of 5ºC±2ºC followed by 55ºC±2ºC - T1) and mechanical cycling (100,000 cycles of 50 kN and 2 Hz - T2). Replicas of samples were rebuilt after each cycling and analyzed under SEM. The data were submitted to Mann-Whitney, Wilcoxon and Friedman testing (a=0.05).Results:
The SB presented higher gaps in the dentin than the enamel, while there was no difference between the substrate for the CL. In the dentin, the CL showed better marginal sealing than the SB. The opposite occurred in the enamel. There were no significant differences between the baseline, thermal and mechanical cycling for any experimental condition.Conclusions:
The outcomes of the present study showed that the adhesive system and margin location have an important effect on the marginal adaptation of composite restorations. 相似文献16.
Volkan Turp Deniz Sen Betul Tuncelli Mutlu ?zcan 《The journal of advanced prosthodontics》2013,5(3):226-233
PURPOSE
This study evaluated the adhesion of 10-MDP containing self-etch and self-adhesive resin cements to dentin with and without the use of etch-and-rinse technique.MATERIALS AND METHODS
Human third molars (N=180) were randomly divided into 6 groups (n=30 per group). Conventional (Panavia F2.0, Kuraray-PAN) and self-adhesive resin cements (Clearfil SA, Kuraray-CSA) were bonded to dentin surfaces either after application of 3-step etch-and-rinse (35% H3PO4 + ED Primer) or two-step self-etch adhesive resin (Clearfil SE Bond). Specimens were subjected to shear bond strength test using the universal testing machine (0.5 mm/min). The failure types were analyzed using a stereomicroscope and quality of hybrid layer was observed under a scanning electron microscope. The data (MPa) were analyzed using two-way ANOVA and Tukey''s tests (α=.05).RESULTS
Overall, PAN adhesive cement showed significantly higher mean bond strength (12.5 ± 2.3 - 14.1 ± 2.4 MPa) than CSA cement (9.3 ± 1.4 - 13.9 ± 1.9 MPa) (P<.001). Adhesive failures were more frequent in CSA cement groups when used in conjunction with two-step self-adhesive (68%) or no adhesive at all (66%). Hybrid layer quality was inferior in CSA compared to PAN cement in all conditions.CONCLUSION
In clinical situations where bonding to dentin substrate is crucial, both conventional and self-adhesive resin cements based on 10-MDP can benefit from etch-and-rinse technique to achieve better quality of adhesion in the early clinical period. 相似文献17.
Alaa Abdul MAHDI Victoria BOLA?OS-CARMONA Santiago GONZALEZ-LOPEZ 《Journal of applied oral science : revista FOB》2013,21(4):369-375
Objectives
To investigate the bond strength and seal ability produced by AH Plus/gutta-percha, EndoREZ and RealSeal systems to root canal dentin.Material and Methods
Sixty extracted single-root human teeth, instrumented manually to size 40, were divided into three groups (n=20) according to the sealer used; G1: AH Plus, G2: EndoREZ, and G3: RealSeal sealers. After filling using the lateral condensation technique, each sealer group was randomly divided into two subgroups according to the tests applied (n=10 for µPush-out test and n=10 for fluid filtration test). A fluid filtration method was used for quantitative evaluation of apical leakage. Four 1-mm-thick slices (cervical and medium level) were obtained from each root sample and a µPush-out test was performed. Failure modes were examined under microscopy at 40x, and a one-way ANOVA was applied to analyze the permeability. Non-parametrical statistics for related (Friedman''s and Wilcoxon''s rank tests) or unrelated samples (Kruskal-Wallis'' and Mann-Whitney''s tests) allowed for comparisons of µPush-out strength values among materials at the different levels. Statistical significance was accepted for p values <.05.Results
There are no significant differences among fluid filtration of the three sealers. The sealer/core material does not significantly influence the µPush-out bond strength values (F=2.49; p=0.10), although statistically significant differences were detected with regard to root level (Chi2=23.93; p<0.001). AH Plus and RealSeal obtained higher bond strength to intraradicular dentin in the medium root slices.Conclusions
There are no significant differences between the permeability and global µPush-out bond strength to root canal dentin achieved by AH Plus/gutta-percha, EndoREZ and RealSeal systems. 相似文献18.
Susan Hattar Muhanad M. Hatamleh Faleh Sawair Mohammad Al-Rabab’ah 《Saudi Dental Journal》2015,27(2):70-74
Objectives
The aim of this study was to evaluate the strength of the bond between newly introduced self-adhesive resin cements and tooth structures (i.e., enamel and dentin).Methods
Three self-adhesive cements (SmartCem2, RelyX Unicem, seT SDI) were tested. Cylindrical-shaped cement specimens (diameter, 3 mm; height, 3 mm) were bonded to enamel and dentin. Test specimens were incubated at 37 °C for 24 h. The shear bond strength (SBS) was tested in a Zwick Roll testing machine. Results were analyzed by one-way ANOVA and t-test. Statistically significant differences were defined at the α = 0.05 level. Bond failures were categorized as adhesive, cohesive, or mixed.Results
The SBS values ranged from 3.76 to 6.81 MPa for cements bonded to enamel and from 4.48 to 5.94 MPa for cements bonded to dentin (p > 0.05 between surfaces). There were no statistically significant differences between the SBS values to enamel versus dentin for any given cement type. All cements exhibited adhesive failure at the resin/tooth interface.Conclusions
Regardless of their clinical simplicity, the self-adhesive resin cements examined in this study exhibit limited bond performance to tooth structures; therefore, these cements must be used with caution. 相似文献19.
Jin-Hun Jeon Hae-Young Kim Ji-Hwan Kim Woong-Chul Kim 《The journal of advanced prosthodontics》2014,6(6):468-473
PURPOSE
This study aimed to evaluate the accuracy of digitizing dental impressions of abutment teeth using a white light scanner and to compare the findings among teeth types.MATERIALS AND METHODS
To assess precision, impressions of the canine, premolar, and molar prepared to receive all-ceramic crowns were repeatedly scanned to obtain five sets of 3-D data (STL files). Point clouds were compared and error sizes were measured (n=10 per type). Next, to evaluate trueness, impressions of teeth were rotated by 10°-20° and scanned. The obtained data were compared with the first set of data for precision assessment, and the error sizes were measured (n=5 per type). The Kruskal-Wallis test was performed to evaluate precision and trueness among three teeth types, and post-hoc comparisons were performed using the Mann-Whitney U test with Bonferroni correction (α=.05).RESULTS
Precision discrepancies for the canine, premolar, and molar were 3.7 µm, 3.2 µm, and 7.3 µm, respectively, indicating the poorest precision for the molar (P<.001). Trueness discrepancies for teeth types were 6.2 µm, 11.2 µm, and 21.8 µm, respectively, indicating the poorest trueness for the molar (P=.007).CONCLUSION
In respect to accuracy the molar showed the largest discrepancies compared with the canine and premolar. Digitizing of dental impressions of abutment teeth using a white light scanner was assessed to be a highly accurate method and provided discrepancy values in a clinically acceptable range. Further study is needed to improve digitizing performance of white light scanning in axial wall. 相似文献20.
André de Carvalho SALES-PERES Juliane Avansini MARSICANO Rudan Paraíso GARCIA Moacir Rossi FORIM Maria Fatima das Gra?as Fernandes da SILVA Sílvia Helena de Carvalho SALES-PERES 《Journal of applied oral science : revista FOB》2013,21(6):597-600