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Objective: To evaluate the microtensile bond strength of 2 adhesive systems (Adper Single Bond Plus [3M ESPE] and Clearfil SE Bond [Kuraray]) to carious or normal dentin, with or without previous treatment with Nd:YAG laser or Nd:YAG laser associated with fluoride. Method and Materials: Dentin surfaces of 60 human third molars were exposed. Teeth were divided into 12 groups; groups 1 to 6 were submitted to pH cycling for artificial caries, and groups 7 to 12 remained with normal dentin. Dentin surfaces received 3 treatments: laser Nd:YAG irradiation (60 mJ, 15 Hz, and 0.9 W) for 1 minute; laser Nd:YAG irradiation associated with fluoride in gel; and no treatment (controls). In experimental groups, adhesive systems were applied in accordance with the manufacturers' instructions, and a composite resin block (Filtek Z250, 3M ESPE) was made incrementally for the microtensile bond strength test. The teeth were sectioned serially in both x and y directions, and sticks were submitted to microtensile bond strength testing in a universal testing machine. Results: According to ANOVA and Tukey (P < .05), the highest mean bond strengths were obtained in groups of normal dentin treated with Clearfil SE Bond (40.65 MPa) and Single Bond (34.2 MPa). The presence of carious dentin significantly decreased the mean bond strengths of the 2 adhesive systems whether or not they were previously laser irradiated. Nevertheless, Clearfil SE Bond presented the best microtensile bond strength on an irradiated surface. Moreover, laser irradiation associated with fluoride also decreased the bond strength values of the 2 adhesive systems. Conclusion: After excavating a cavity with caries-affected dentin, the use of Nd:YAG laser followed by a self-etching adhesive system is the best clinical choice when considering bond strength, compared with the total etching- based system and laser. (Quintessence Int 2009;40:145-153). [ABSTRACT FROM AUTHOR]

Objective: To evaluate the in vitro influence of prior silane application on the microshear bond strength (μSBS) of Scotchbond Universal Plus to glass ceramic., Materials and Methods: Thirty blocks of lithium disilicate ceramic were etched with hydrofluoric acid for 20 s and distributed into Group 1 (no silane and no adhesive), Group 2 (adhesive), Group 3 (silane + adhesive). Three cylinders of resin cement were made on each ceramic block. Five blocks (n = 15 cylinders) were subjected to the μSBS test after 24 h, and the other five blocks (n = 15 cylinders) were tested after 6 months of water storage., Results: According to two-way ANOVA, followed by Tukey's test, the means of μSBS (MPa), denoted by different letters, show significant differences (p < 0.05): after 24 h-Group 1 (31.7) B , Group 2 (43.3) A , and Group 3 (31.3) B ; after 6 months-Group 1 (14.8) B , Group 2 (33.6) A , and Group 3 (30.3) A . After 6 months of storage, there was a significant decrease in μSBS for Groups 1 and 2, along with an increase in adhesive failures across all groups., Conclusions: Prior application of silane did not increase the μSBS between Scotchbond Universal Plus and ceramic, and there was degradation at the bond interface over time., Clinical Significance: Prior application of a silane agent is not necessary when using Scotchbond Universal Plus for bonding to glass ceramics. Regardless of the prior application of silane, there is degradation at the bond interface over time., (© 2024 Wiley Periodicals LLC.)

This laboratory study aimed to evaluate the effects of zirconium dioxide (ZrO2) slurry surface treatment on the bond strength of ultratranslucent zirconia to resin cement using different ceramic primers. The surface morphology was evaluated by scanning electron microscopy (SEM) and atomic force microscopy (AFM), and the interface was evaluated by SEM. Additionally, the phase composition was analyzed by X-ray diffraction (XRD). Specimens of zirconia (n=120) were obtained and divided into two groups according to the surface treatment: (1) airborne particle abrasion with 50-μm aluminum oxide (n=60) and (2) ZrO2 slurry (n=60). The 60 specimens were then further divided into three groups (n=20) according to the ceramic primer application: no primer (NP), Monobond N (MB), and Clearfil ceramic primer (CP). Four resin cement cylinders were built on each ceramic specimen. Half of the specimens (n=10) were subjected to a microshear bond strength (μSBS) test after 24 hours of storage in distilled water, and the other half (n=10) were subjected to a μSBS test after thermocycling. Additional specimens were prepared for SEM, AFM, and XRD analyses. According to the Kruskal-Wallis and Student-Newman-Keuls post hoc tests, the μSBS values were significantly higher for MB and CP than for NP (p<0.05), and there were no significant differences in μSBS for both surface treatments associated with MB and CP after 24 hours of storage (p>0.05). Thermocycling significantly decreased the μSBS values for all specimens, especially for the NP groups and ZrO2 slurry treatment groups, and gaps at the interface were observed by SEM. SEM and AFM analyses showed agglomerate-type irregularities on the ceramic surface for ZrO2 slurry treatment. XRD spectra showed that ZrO2 slurry did not cause phase transformation. It was concluded that ZrO2 slurry promoted irregularities on the ultratranslucent zirconia surface, not causing phase transformation; moreover, the values of μSBS were comparable to those of airborne particle abrasion with aluminum oxide. However, neither surface treatment nor ceramic primer prevented the degradation of the interface., (©Operative Dentistry, 2024.)

Objectives: This laboratory study evaluated the effect of three polishing systems on the surface roughness and gloss of resin composites., Materials and Methods: Thirty specimens (6 mm Ø × 8 mm) were fabricated from each of three resin composites: Z 350 XT (nanofill), Harmonize (nanohybrid), and Estelite Omega (supranonofill). All specimens were photopolymerized using a multi-peak LED curing unit (VALO-Standard mode), having a exitance irradiance of approximately 1000 mW/cm 2 against a polyester strip (PS). 2 mm was then removed from the irradiated end (finished) using #320 abrasive paper (F). Specimens were then randomly polished (P) using a one-step (1S) (OneGloss), two-step (2S) (EVE Diacomp Twist Basic CA), or 3-step (3S) (Astropol P) system (n = 10). For PS, F, and P groups, surface roughness (Ra) was measured using a surface roughness tester, and surface gloss was measured with a glossmeter. For each specimen, the percent recovery to the PS value (%R) of surface roughness and surface gloss were calculated. Data were analyzed using two-way ANOVA, followed by Tukey's test. Surface roughness and gloss values were submitted to Pearson's correlation test (α = 0.05). All statistical testing was performed using a pre-set alpha of 0.05., Results: The interaction term [resin composite × polishing system] was significant for both surface roughness (p = 0.001) and gloss (p = 0.0001). For all resin composites, the 2S and 3S systems provided a higher %R of surface roughness and gloss compared to those of the 1S system. There was a negative correlation between surface roughness and gloss, but only a few combinations showed strong correlations., Conclusions: The 2S and 3S polishing systems provided surfaces having greater smoothness and gloss compared to the 1S system. The ability to recover surface roughness and gloss was dependent on type of resin composite filler classification., Clinical Significance: The 3S and 2S polishing systems were more effective in achieving PS values than was the 1S system for all tested resin composites. However, individual polishing systems performed differently depending on type of resin composite., (© 2023 Wiley Periodicals LLC.)

Objectives: To compare, in vitro, resin cement excess removal techniques at the veneer-tooth interface., Materials and Methods: Anterior human teeth were restored with ceramic veneers and randomly divided according to the following techniques (n = 10): removal of excess resin cement with brush and dental floss, followed by light-curing with Valo (Group 1) or Elipar (Group 2) for 1 min and 40 s; tack-curing with Valo (Group 3) or Elipar (Group 4) for 1 s; and tack-curing with Valo (Group 5) or Elipar (Group 6) for 5 s. The tack-curing was followed by removal of excess with probe and dental floss and light-curing for 1 min and 40 s. The area of excess resin cement (mm 2 ) was measured in micro-CT images using AutoCAD program. The failures at the cervical margin in the X, Y, and Z axes (µm) of greater value were measured using the DataViewer program. The specimens were submitted to microleakage with 2% basic fuchsin., Results: According to the Kruskal-Wallis and multiple comparison test, the highest area of excess resin cement was found in Group 1 (5.06 mm 2 ), which did not differ statistically from Groups 2 (3.70 mm 2 ) and 5 (2.19 mm 2 ). Groups 2, 3 (1.73 mm 2 ), 4 (1.14 mm 2 ), and 5 (2.18 mm 2 ) did not differ statistically. Group 6 (0.77 mm 2 ) obtained the lowest value, which did not differ statistically from Groups 3 and 4. According to the Kruskal-Wallis and Dunn test, there was no significant difference in failures in X (p = 0.981), Y (p = 0.860), and Z (p = 0.638) axes and no significant difference in microleakage (p = 0.203) among the groups., Conclusions: Tack-curing for 1 s or 5 s, followed by removal of excess resin cement using a probe and a dental floss, tended to result in a lower amount of excess material around the margin., Clinical Relevance: The technique used for resin cement excess removal influences the amount of excess leaved at the veneer-tooth interface. Tack-curing for 1 s or 5 s is recommended to mitigate the excess resin cement., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: The bond capacity of universal adhesives should be comparable to a specific primer for zirconia. Thus, this study evaluated the bond strength to zirconia of four universal adhesives and a zirconia primer over long-term storage., Materials and Methods: The surfaces of 75 samples of zirconia were sandblasted with 50 µm aluminum oxide particles and then divided into groups ( n = 15): G1 - Single Bond Universal (SBU); G2 - All Bond Universal; G3 - Peak Universal Bond; G4 - Ambar Universal (AU), and G5 - Z-Prime Plus (ZP). A cone of resin composite was constructed on the applied materials. The samples were submitted to a tensile bond strength test after 24 h using a universal testing machine. Then, the remaining materials were removed from the sample surfaces, and the surfaces were polished and sandblasted again as previously described to obtain the same groups. These new samples were stored in distilled water at 37°C for 12 months and then submitted to a tensile bond strength test. The data were analyzed by two-way analysis of variance and Tukey's test ( α =0.05)., Results: The material factor ( P = 0.001) and the storage factor ( P = 0.001) were significant, and the interaction was not significant ( P = 0.117). According to Tukey's test, bond strength mean values (in MPa) followed by distinct letters were significantly different. After 24 h, G5 = 21.12 A, G1 = 20.55 A, G4 = 19.19 AB, G2 = 14.22 B, and G3 = 8.44 C. After 12 months, G1 = 7.37 A, G5 = 5.61 AB, G4 = 4.97 B, G2 = 3.32 C, and G3 = 1.93 D. After 12 months of storage, all groups' bond strength significantly decreased., Conclusions: SBU and AU had bond strengths comparable to ZP after 24 h. No material resisted water degradation., Competing Interests: There are no conflicts of interest., (Copyright: © 2023 Contemporary Clinical Dentistry.)

Purpose: To evaluate the fracture load of monolithic, single-tooth implant-supported crowns cemented on solid or Ti-base (Variobase C) abutments., Materials and Methods: Besides abutment types (solid and Ti-base abutments), two ceramic systems (IPS e.max CAD and Zirconia inCoris ZI) and two occlusal thicknesses (0.5 and 1.5 mm) were also investigated in this study. In total, eight groups (n = 8) with 64 maxillary second premolar crowns were fabricated. All the crowns were cemented with resin cement, and the screw accesses in Ti-base groups were sealed with composite resin. After mechanical cycling, the specimens were submitted to fracture load test with the maximum force recorded in Newtons (N). Three-way analysis of variance (ANOVA) and Tukey post hoc test were used for statistical analyses (α = .05)., Results: Both the abutment type (P = .0001) and the ceramic system (P = .0001) significantly affected the results. Screw-access channels reduced the fracture load of crowns by half compared to those cemented on solid abutments. The 1.5-mm and 0.5-mm zirconia crowns placed on solid abutments had similar highest fracture loads, while the e.max CAD groups positioned on Ti-base abutments showed significantly lower values compared with other groups., Conclusion: The screw access reduces the resistance of crowns supported by Ti-base abutments compared to crowns cemented on solid abutments. The inCoris ZI showed a higher fracture load than the IPS e.max CAD regardless of the abutment type and thickness.

The purpose of this in vitro study was to evaluate the effect of gastric acid on the surface roughness and biofilm formation of bulk-fill composite resins. Twenty-seven samples of each composite resin were obtained: G1: Filtek Z250 XT (Z250), G2: Filtek Bulk Fill (FTK), G3: Tetric N-Ceram Bulk Fill (TTC), and G4: Aura Bulk Fill (AUR). The samples were quantitatively analyzed for surface roughness (Ra) using a roughness tester (n=15) and for biofilm formation (Cn) by the counting of colony-forming units (CFUs/mL) (n=9) in three different moments: after polishing (Ra0 and Cn0), after gastric acid immersion (Ra1 and Cn1), and after gastric acid and simulated tooth brushing (Ra2 and Cn2). Qualitative analysis through surface topography (n=3) was evaluated by scanning electron microscopy (SEM). Ra values were subjected to two-way repeated measures ANOVA, followed by Tukey's test. Cn values were subjected to Kruskal-Wallis analysis, followed by multiple comparisons analysis (α=0.05). Z250 and FTK showed significant increases in surface roughness at Ra1. There were fewer CFUs/mL on TTC and AUR in relation to those of Z250 and FTK for Cn0, Cn1 and Cn2. The SEM images showed that gastric acid increased the formation of cracks, exposure of fillers and micro cavities for all composite resins. After tooth brushing, the topographical changes were more evident but did not influence biofilm formation. The gastric acid promoted both degradation of the surfaces and bacterial adhesion for all composite resins.

The rehabilitation of severely worn teeth is a complex challenge for dental practitioners. There are many different types of dental materials and restorative techniques, and there is not a single way to achieve the desired result. This clinical report demonstrates a complete oral rehabilitation with composite resins when using an indirect application and direct techniques, with the support of the Lucia Jig technique, the Willis technique, and diagnostic waxing for the vertical dimension correction. The wide clinical improvement was achieved with the recovery of the function, the esthetics, and the increase of vertical dimension of occlusion through the planned treatment. The proposed treatment maintained the natural teeth, without the intense wear by the application of the composite resins instead of ceramics, together with excellent conditions for the patient to control the posttreatment and extend the durability, with the correct follow-up of appointments. Young patients with extensive dental wear and the loss of vertical dimension should not be directly submitted to ceramic treatments, with preparations for full crowns. Oral rehabilitation using composite resins, either directly or indirectly, allows for the recovery of the function and esthetics, without the intense predictable dental wear, and reduced financial investment.

Objective: The objective of this laboratory study was to assess the effect of immediate dentin sealing (IDS) on the fracture strength of teeth restored with ultrathin occlusal veneers made of a polymer-infiltrated ceramic network (PICN - Vita Enamic) with different fissure/cusp thicknesses., Methods: Forty third molars were identically prepared in the dentin and allocated into four groups (n = 10) according to the fissure/cusp thickness of the occlusal veneers (0.3/0.6 mm or 0.6/0.9 mm) and the application or not of the IDS technique. Ten sound third molars were used as the control group. IDS was performed using a universal adhesive system (Single Bond Universal). The prepared teeth were scanned (Cerec software, version 4.1), and the occlusal veneers were shaped following the occlusal anatomy of a right second molar. Blocks of PICN were milled in the unit inLab MC XL. Following luting with Single Bond Universal and RelyX Ultimate, the fracture strength of the specimens was obtained with a universal testing machine. The fractures were classified as reparable or irreparable. Fracture strength values were analyzed with 2-way and 1-way ANOVA (α = 0.05) and Tukey's test., Results: Only the IDS factor was significant (p = 0.001). The teeth restored with IDS (2875 ± 508 N) achieved significantly higher fracture strength than the teeth restored without IDS (2263 ± 354 N) (p < 0.05). The fracture strength of the specimens with IDS did not differ significantly from that of the sound teeth (3230 ± 620 N). The fractures were predominantly reparable., Conclusion: IDS improved the fracture strength of ultrathin occlusal veneers made of PICN., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

This study aimed to evaluate the effect of three hydrofluoric acid (HF) etching periods on the micro-tensile bond strength between two CAD-CAM ceramic systems [Vita Suprinity (VS) and feldspathic CEREC blocs (CB)] and a composite resin. The ceramics were categorized into six groups based on the surface conditioning protocol used, as follows: G1: CB-HF 5% for 20 s; G2: CB-HF 5% for 40 s; G3: CB-HF 5% for 60 s; G4: VS-HF 5% for 20 s; G5: VS-HF 5% for 40 s; G6: VS-HF 5% for 60 s. Scotchbond Universal was applied onto the pretreated ceramic surfaces and covered with Filtek Z350 XT composite resin. After 24 h, the specimens were cut into microbars (n = 16) and a micro-tensile bond strength test (μTBS) was carried out. An optical microscope was used to examine the fractured microbars. The results showed statistically significant differences between the factors tested (p < 0.01). Moreover, the mean MPa of G1(17.27), G2(13.03), G3(12.82), G4(15.83), G5(21.66), and G6(14.50) was seen to significantly differ. The predominant failure type observed was adhesive, and all three periods of HF etching produced satisfactory bonding between the composite resin and CB. An etching time of 40 s provided the highest μTBS value for VS., (© 2021. The Society of The Nippon Dental University.)

Purpose: This systematic review and meta-analysis of in vitro studies compared the prepolymerized acrylic resin used for CAD/CAM complete denture manufacturing versus the heat-polymerized acrylic resin for conventional complete dentures in terms of surface roughness, wettability, hardness and flexural strength., Materials and Methods: An electronic search was performed in the PubMed, Embase, LILACS and Web of Science databases, without language or date restrictions. Gray literature and manual search tools were also used. The systematic review was carried out by two researchers independently, following the inclusion criteria: in vitro studies testing the CAD/CAM acrylic resin with a control group of heat-polymerized acrylic resin which compared at least one of the four material properties above. The meta-analysis was performed separately for each property, using a random effect model., Results: Of the 914 studies found by means of search strategies, 698 were selected for the systematic review. After applying the eligibility criteria, only 17 articles were selected for the qualitative analysis in the systematic review; among these, 14 were included in the quantitative meta-analysis. The CAD/CAM prepolymerized acrylic resin in blocks had similar properties when compared to heat-polymerized acrylic resin in almost all outcome measures, with the exception of a statistically significant reduction in surface roughness., Conclusions: Based on the findings of this systematic review and meta-analysis, equally satisfactory results can be expected from dental prosthesis manufactured by the CAD/CAM system when compared to conventional ones, with the additional potential of reducing the pigmentation and attached microorganisms due to the reduced surface roughness of the prepolymerized resin., (© 2021 by the American College of Prosthodontists.)

The purpose was to evaluate, in vitro, the fracture strength of teeth restored with 0.3- or 0.6-mm-thick occlusal veneers made of Vita Enamic® bonded to enamel or dentin. Fifty third molars were allocated into five groups (n=10): Group C - control (sound teeth); Group 0.3E - 0.3-mm-thick occlusal veneers bonded to enamel; Group 0.6E - 0.6-mm-thick occlusal veneers bonded to enamel; Group 0.3D - 0.3-mm-thick occlusal veneers bonded to dentin; Group 0.6D - 0.6-mm-thick occlusal veneers bonded to dentin. After luting with Single Bond Universal and Filtek Z-100, the samples were subjected to fracture strength test in a universal testing machine. The fractures were classified as irreparable and reparable. Data were analyzed with 2-way and 1-way ANOVA (α=.05) followed by Tukey's test. The teeth restored with 0.3-mm-thick occlusal veneers (2658 N) achieved significantly higher fracture strength compared to the teeth restored with 0.6-mm-thick occlusal veneers (2070 N) (p=0.017). The teeth restored with occlusal veneers bonded to enamel (2648 N) had significantly higher fracture strength compared to the teeth restored with occlusal veneers bonded to dentin (2049 N) (p=0.015). Group C (3355 N) and Group 0.3E (2965 N) did not differ significantly from each other, being the fracture strength significantly higher than the other groups (p<0.05). The fractures were predominantly reparable. The teeth restored with 0.3-mm-thick occlusal veneers achieved higher fracture strength compared to the teeth restored with 0.6-mm-thick occlusal veneers. The supporting substrate influenced the fracture strength, which was higher for the teeth restored with occlusal veneers bonded to enamel.

Objectives: To evaluate, in vitro, the fracture load of IPS e.max CAD occlusal veneers at thicknesses of either 0.3 or 0.6 mm luted to enamel or dentin., Materials and Methods: Fifty human molars were randomly distributed into five groups (n = 10): G1 - healthy teeth (control); G2-0.3-mm-thick veneers luted to enamel; G3-0.6-mm-thick veneers luted to enamel; G4-0.3-mm-thick veneers luted to dentin; and G5-0.6-mm-thick veneers luted to dentin. After the luting procedures, the specimens were immersed in distilled water at 37°C for 24 hours and then subjected to mechanical loading (10 6  cycles at 200 N load). The specimens were subjected to a fracture load test in a universal testing machine. Two-way ANOVA and Tukey's test (α = 0.05) were used to analyze data., Results: Only the thickness factor was significant (P = .002). Values of fracture load followed by distinct letters represent significant differences (P < .05): G1 (3204 N ± 730) ab ; G2 (3144 N ± 729) ab ; G3 (2489 N ± 606) b ; G4 (3591 N ± 776) a ; and G5 (2770 N ± 598) ab ., Conclusion: IPS e.max ultrathin occlusal veneers luted to enamel or dentin obtained fracture load comparable to that of the healthy tooth., Clinical Significance: IPS e.max CAD ultrathin occlusal veneers at 0.3 or 0.6-mm-thick seem to provide good perspectives in relation to the clinical use., (© 2020 Wiley Periodicals LLC.)

The aim was to evaluate the microtensile bond strength (mTBS) to dentin and interfacial stress in a class II cavity restored with bulk-fill or conventional composite resins and the margin interfaces. Vertical slot class II cavities in the mesial face, with the gingival end in dentin, were prepared in 72 third molars, being divided into groups (n=24): G1-Tetric N-Ceram; G2-Tetric N-Ceram Bulk-Fill; G3-SonicFill. Clearfil SE Bond adhesive system was used in all groups. Half of the teeth in each group (n=12) were submitted to thermo-mechanical cycling (TMC). Restored teeth (n=9) were cut perpendicular to obtain beams, which were submitted to a mTBS test in an EMIC machine. The cervical margins in dentin of the restored teeth (n=3) were assessed using SEM through epoxy resin replicas as well as the section of the restoration. Interfacial stresses after load application were calculated by 2D finite element analysis. The mTBS means-MPa followed by different letters represent statistical difference by ANOVA and Games-Howell's test (p<0.05): Without TMC: G1-15.68±6.10a; G2-10.08±5.21ab; G3-7.98±3.76b. With TMC: G1-9.70±5.52a; G2-5.79±1.42a; G3-4.37±1.87a. Interfacial stress (MPa) was 4.4 for SonicFill, 3.9 for Tetric N-Ceram, and 3.5 for Tetric N-Ceram Bulk-Fill. SEM images showed continuous margins for all composite resin restorations. It was possible to conclude that SonicFill obtained a slightly higher interfacial stress and lower bond strength to dentin in comparison with Tetric N-Ceram and Tetric N-Ceram Bulk-Fill. Continuous margin interfaces were obtained for Tetric N-Ceram, Tetric N-Ceram Bulk-Fill, and SonicFill. However, voids were observed in the SonicFill restorations.

The aim was to evaluate, in vitro, the influence of pH cycling on microtensile bond strength (µTBS) and percentage of nanoleakage (%NL) in the dentin-adhesive interface. Flat dentin surfaces were obtained in 56 extracted third molars. The teeth were randomly divided into four groups (n=14): G1- Single Bond Universal (etch-and-rinse mode); G2- Single Bond Universal (self-etch mode); G3- Scotchbond Multi-Purpose; G4- Clearfil SE Bond. A block of composite was built on the adhesive area. Eight tooth/resin sets were cut parallel to the tooth's long axis to obtain 48 beams (0.8 mm2) for each group. Half of the beams were submitted to four cycles of pH cycling (demineralizing solution for 6 h and remineralizing solution for 18 h). The samples were submitted to µTBS test in a universal testing machine. Six tooth/resin sets were cut parallel to the tooth's long axis to obtain three slices of the central region (1.0 mm thickness). Half of the slices were submitted to pH cycling. The nanoleakage methodology was applied to obtain the %NL at the adhesive interfaces. According to two-way ANOVA, the interaction between factors (adhesive system x storage) was significant (p=0.0001) for µTBS and %NL. After pH cycling, there was a significant decrease in µTBS and a significant increase in %NL for all adhesives. The adhesives applied in the self-etch mode obtained lower %NL, differing significantly from the etch-and-rinse adhesives. It was concluded that the pH cycling negatively influenced the µTBS and %NL for all adhesives evaluated. However, self-etch adhesives allowed less %NL.

The aim was to evaluate the effect of 2% grape seed extract (GSE) containing phosphoric acid (PhA) on the bond strength to enamel and dentin. The control group was 37% PhA. The following three PhA formulations with 2% GSE and 20% ethanol were obtained: GSE5 = 5% PhA; GSE10 = 10% PhA; and GSE20 = 20% PhA. The enamel and dentin surfaces of molars were etched with the acid solutions, followed by Scotchbond Multi-Purpose adhesive and composite resin application. The tensile bond strength (TBS) test evaluated the bond to enamel after 24 h, and the microtensile bond strength (μTBS) test evaluated the bond to dentin after 24 h and 12-month water storage. Etched enamel and dentin were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The TBS data were submitted to one-way ANOVA, while µTBS data were submitted to two-way ANOVA and Tukey's test (α = 0.05). The TBS (MPa) to enamel did not significantly differ among the control (48.1 ± 15.7), GSE5 (46.1 ± 9.6), GSE10 (49.8 ± 13.6) and GSE20 (44.1 ± 11.9) groups (p = 0.537). The µTBS (MPa) to dentin of the control (28.4 ± 14.4) and GSE20 (24.1 ± 8.1) groups were significantly higher than those of the GSE5 (16.8 ± 7.4) and GSE10 (17.5 ± 6.6) groups at 24 h (p < 0.006). After 12-month storage, only GSE5 (21.0 ± 7.8) and GSE10 (17.6 ± 8.0) did not show significantly decreased μTBS (p > 0.145). SEM micrographs showed a shallower enamel etching pattern for GSE5. AFM images showed the formation of collagenous globular structures for GSE5 and GSE10. The different acid solutions did not influence the TBS to enamel, and the µTBS to dentin was stable over time when dentin was etched with GSE5 and GSE10.

The aim was to evaluate the influence of different dentin preparation mode in the smear layer characteristics (SL), hybrid layer (HL), and microtensile bond strength (µTBS) to dentin with two resin cements. The occlusal dentin of 120 third molars was exposed. The teeth were divided into 4 groups (n=30) according to the dentin preparation mode: 1- fine grain diamond bur; 2- coarse grain diamond bur; 3- multi laminate carbide steel bur; and, 4- ultrasonic CV Dentus diamond bur. Each treated dentin group was divided into 2 sub-groups (n=15) according to the resin cement: (1) RelyX U200 and (2) RelyX ARC. Resin composite blocks were cemented on dentin. After storage at 37o C for 24 h, beams with a cross section area of 1.0 mm2 were obtained, and tested in a universal testing machine at a crosshead speed of 0.5 mm/min. Two additional teeth for each sub-group were prepared to analyze the SL and HL on a scanning electron microscopy. According to Kruskal-Wallis test and Dunn tests, there was no significant difference in µTBS among the rotary instruments within each resin cement group. RelyX ARC obtained higher µTBS values compared to RelyX U200 (p<0.05). RelyX ARC formed evident HL, which was not observed for RelyX U200. The dentin mode preparation did not influence the µTBS of the resin cements. The SL was different for all instruments. The cementing agent is more determinant in the hybrid layer formation and bond strength to dentin than the instruments applied on dentin.

The purpose of this study was to investigate the marginal adaptation and microleakage of SonicFill composite with different photopolymerization techniques. Class II cavities were prepared in 40 premolars and divided into groups according to the photopolymerization technique (n = 10): G1:1200 mW/cm 2 for 20 s; G2:1200 mW/cm 2 for 40 s; G3:Soft-start with 650 mW/cm 2 for 5 s and 1200 mW/cm 2 for 15 s; G4:Soft-start with 650 mW/cm 2 for 10 s and 1200 mW/cm 2 for 30 s. The cavities were restored with OptiBond FL adhesive and SonicFill. Epoxy resin replicas were obtained before and after thermocycling. The occlusal and cervical margins were analyzed with scanning electron microcopy and expressed as the percentage of continuous margins (%CM). The specimens were submitted to microleakage with silver nitrate. ANOVA and Tukey's test revealed that the %CM at the linguo-occlusal margin for group 1 (83.19%) was significantly different from groups 2, 3 and 4, which had values over 95%. At the cervical margin, there was no statistically significant difference between the groups. After thermocycling, there was a significant decrease in %CM. The predominant score of microleakage was 1 in enamel and 3 in dentin. The SonicFill composite led to gap formation and microleakage, especially in the dentin at the cervical margin, regardless of the photopolymerization technique employed.

The present study aimed to evaluate the microtensile bond strength (μTBS) of novel computer-aided design/computer-aided manufacturing (CAD/CAM) restorative materials to dentin using different adhesive strategies. Thirty-two crowns were milled using CAD/CAM materials (Vita Mark II as control, Vita Suprinity, Vita Enamic and Lava Ultimate) and luted to dentin using different resin cements (RelyX ARC, RelyX Unicem 2 and RelyX Ultimate). The specimens were stored in 100% relative humidity at 37°C for 24 h and sectioned. The samples (n = 16) with cross-sectional areas of approximately 0.90 mm2, were submitted to a μTBS test in a universal testing machine with a crosshead speed of 0.5 mm/min. The samples were analyzed with SEM to determinate the failure mode. According to 2-way ANOVA and Tukey's test (α=0.05), the interaction effect (material x luting strategy) was significant (p=0.001). Regardless of the luting strategy, a higher μTBS was obtained with Lava Ultimate and Vita Enamic, which were significantly different from Vita Mark II and Vita Suprinity (p<0.05). For Vita Mark II, Vita Suprinity, Vita Enamic, and Lava Ultimate, the μTBS obtained with RelyX Unicem 2 was not significantly different from that obtained with RelyX ARC or RelyX Ultimate. All groups obtained at least three types of failure. The adhesive strategy with self-adhesive resin cement was comparable to conventional resin cement with total-etch or self-etch adhesive techniques in the bond of novel CAD/CAM materials to dentin.

Purpose: The aim of this study was to evaluate the surface roughness and analyze the surface topography of five different CAD/CAM ceramics and one CAD/CAM composite resin for CEREC after milling and postmilling procedures., Materials and Methods: Blocks of the ceramics Mark II, IPS Empress CAD, IPS e.max CAD, Suprinity and Enamic, and blocks of the composite resin Lava Ultimate were milled at CEREC MCXL. Ten flat samples of each material were obtained. The surface roughness (Ra) test was performed before and after milling, crystallization, polishing, and glaze when indicated, followed by SEM and AFM analysis. Data were submitted to one-way ANOVA with repeated measures and the Tukey HSD test (α = 0.05)., Results: The milling step significantly increased the roughness of all the tested materials (P < .05). Lithium-based ceramics (IPS e.max CAD and Suprinity) were more suitable to roughness than the other tested materials (P < .05)., Conclusions: The polishing methods were able to reduce roughness to baseline values, except for lithium-based ceramics. Glaze reduced significantly the roughness of lithium-based ceramics without a difference from the baseline. SEM and AFM images revealed that glazed surfaces are smoother than polished surfaces., Clinical Significance: All hard-milling CAD/CAM materials, that is, fully sintered, should be only hand polished. The glaze step can be suppressed resulting in time saving. However, the glaze step in soft-milling lithium disilicate is imperative., (© 2017 Wiley Periodicals, Inc.)

Objective: The aim was to evaluate, in vitro , the tensile bond strength to dentin of Scotchbond Universal (SU), All-Bond Universal (AU) and One Coat 7 Universal (OC7) adhesives applied in self-etch mode, after 24 h of storage and after 500,000 loading cycles, using Clearfil SE Bond (SE) as a control., Materials and Methods: The adhesives were applied on the dentin of bovine teeth, followed by the application of a composite resin. Thirty specimens were obtained for each adhesive. Half of the specimens were submitted to cyclic loading for 500,000 cycles. All specimens were submitted to a tensile bond strength test in a universal testing machine at a crosshead speed of 0.5 mm/minute., Results: According to two-way ANOVA and Tukey's test (α=5%), the interaction between the adhesive and cyclic loading factors was significant (p=0.001). The means followed by the same letter represent no significant difference in the bond strength (MPa) after 24 h: OC7=7.86 A (±2.90), SU=6.78 AB (±2.03), AU=5.61 BC (±2.32), and SE=3.53 C (±1.89). After cyclic loading, SE, SU and AU maintained bond strength comparable to 24 h period. There was a significant decrease only for OC7., Conclusion: SU, AU and OC7 had bond strength to dentin comparable to that of SE. Only OC7 had decreased bond strength to dentin after cyclic loading.

Introduction: Material biodegradation that occurs in the mouth may interfere in the bonding strength between the bracket and the enamel, causing lower bond strength values in vivo, in comparison with in vitro studies., Objective: To develop a prototype to measure bracket debonding force in vivo and to evaluate, in vitro, the bond strength obtained with the prototype., Methods: A original plier (3M Unitek) was modified by adding one strain gauge directly connected to its claw. An electronic circuit performed the reading of the strain gauge, and the software installed in a computer recorded the values of the bracket debonding force, in kgf. Orthodontic brackets were bonded to the facial surface of 30 bovine incisors with adhesive materials. In Group 1 (n = 15), debonding was carried out with the prototype, while tensile bond strength testing was performed in Group 2 (n = 15). A universal testing machine was used for the second group. The adhesive remnant index (ARI) was recorded., Results: According to Student's t test (α = 0.05), Group 1 (2.96 MPa) and Group 2 (3.08 MPa) were not significantly different. ARI score of 3 was predominant in the two groups., Conclusion: The prototype proved to be reliable for obtaining in vivo bond strength values for orthodontic brackets.

Background: Because of the many possibilities for endodontically restoring the posterior teeth and the high prevalence of restoration failures, this topic continues to be of major concern. A composite resin (CR) restoration reinforced by a horizontal fiberglass post may improve the fracture resistance of endodontically treated teeth. The authors investigated this possibility by comparing the fracture resistance of molars restored with direct techniques with that of molars restored with indirect techniques., Methods: The authors divided 50 extracted sound third molars into 5 groups: sound teeth, onlay (ON), inlay (IN), direct CR, and transfixed fiberglass post (TFP) plus direct CR. The authors performed standardized mesio-occlusodistal cavity preparations and endodontic treatments. The authors cemented indirect restorations of Lava Ultimate (3M ESPE) adhesively in the ON and IN groups. The authors restored CR group teeth directly with Filtek Z230 XT (3M ESPE). In the TFP group, the authors transfixed 2 fiberglass posts horizontally and restored the teeth directly with CR. Thereafter, the authors submitted the teeth to cyclic fatigue loading with 500,000 cycles at 200 newtons. The authors tested fracture resistance in newtons in a universal testing machine. The authors analyzed data with 1-way analysis of variance and a Tukey test (P < .05)., Results: Sound teeth had the highest fracture resistance. ON had the highest recovery of resistance, followed by TFP. CR had the lowest recovery, which was similar to that of IN., Conclusions: Endodontically treated molars restored with TFP plus CR had fracture resistance similar to those restored with ON, which was higher than that for IN or CR only., Practical Implications: Horizontal TFPs placed inside a composite restoration had the same performance as did ON restorations., (Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to evaluate the thickness of resin cements in the root thirds when using conventional fiberglass posts (CP) and relined fiberglass posts (RP) in weakened roots and to evaluate the morphological characteristics of the dentin-resin interface. Forty human maxillary anterior teeth had the crown sectioned below the cemento-enamel junction. The canals were endodontically treated and weakened with diamond burs. Teeth were divided into four groups (n = 10): Group 1 - CP + RelyX ARC; Group 2 - CP + RelyX U200; Group 3 - RP + RelyX ARC; and Group 4 - RP + RelyX U200. Prior to luting, 0.1% Fluorescein and 0.1% Rhodamine B dyes were added to an adhesive and resin cement, respectively. Slices were obtained from the apical, middle, and cervical thirds of the root. Confocal laser scanning microscopy images were recorded in four areas (buccal, lingual, mesial, distal) of each third. In each area, four equidistant measures of the resin cement were made and the mean value was calculated. The interface morphology was observed. The data were submitted to three-way ANOVA and Tukey's test (α = 0.05). The interaction between fiberglass posts, resin cement, and root thirds was significant (p < 0.0001). The resin cement thicknesses were significantly lower for RP in comparison with CP, except in the apical third. There was no significant difference between the resin cements for RP. There was formation of resin cement tags and adhesive tags along the root for RP. RP favored the formation of thin and uniform resin cement films and resin tags in weakened roots.

Objective: The aim of the study was to evaluate the microtensile bond strength (µTBS) of Scotchbond Universal to dentin using the etch-and-rinse or the self-etch technique after 24 h and 6 months of storage., Materials and Methods: Flat dentin surfaces were obtained in 24 third molars. The teeth were divided into four groups: G1 - Scotchbond Universal applied in the etch-and-rinse mode; G2 - Scotchbond Universal applied in the self-etch mode; G3 - Scotchbond Multi-Purpose; G4 - Clearfil SE Bond. A block of composite was built on the adhesive area. The tooth/resin sets were cut parallel to the long axis to obtain 40 beams (~0.8 mm(2)) for each group. Twenty specimens were immediately submitted to the µTBS test, and the remaining 20 were stored in water for 6 months. Failures and the adhesive interface were analyzed by SEM., Results: According to two-way ANOVA, the interaction between adhesive and storage time was significant (p=0.015).The µTBS (MPa) means were the following: 24 h - G1 (39.37±10.82), G2 (31.02±13.76), G3 (35.09±14.03) and G4 (35.84±11.06); 6 months - G1 (36.99±8.78), G2 (40.58±8.07), G3 (32.44±6.07) and G4 (41.75±8.25). Most failures were mixed. Evidence of hybrid layer and numerous resin tags were noted for Scotchbond Universal applied with the etch-and-rinse mode and Scotchbond Multi-Purpose. A thinner hybrid layer and fewer resin tags were noted for Scotchbond Universal applied in the self-etch mode and Clearfil SE Bond., Conclusion: The results indicate that the µTBS for Scotchbond Universal is comparable to the gold-standard adhesives. Scotchbond Universal applied in the self-etch mode and Clearfil SE Bond revealed higher bond stability compared to the etch-and-rinse mode.

Purposes: (1) To evaluate in vitro the surface roughness of a resin composite covered with three surface sealants and submitted to simulated toothbrushing for different periods; (2) Verify, through scanning electron microscopy (SEM), the presence of surface sealants after simulated toothbrushing; and (3) To evaluate whether the type of dentifrice influences the maintenance of the surface sealant. The study hypothesis was that neither variable would influence the surface roughness of the composite and the maintenance of the surface sealant., Methods: 108 specimens were prepared with the resin Amelogen Plus, and divided into six groups (n = 18) according to the type of surface sealant [Fortify (F), BisCover LV (B) and Permaseal (P)] and toothpaste [Total 12 Clean Mint (CT) and Colgate Total 12 Professional Whitening (PW)]. The samples were subjected to brushing cycles, simulating periods of 6, 12, 18, and 24 months. After each period, the surface roughness of the samples was measured. An additional group of 48 samples was prepared for SEM analysis. The results were analyzed by ANOVA with three fixed variables (sealants, time and toothpaste) and by Tukey's test (α = 0.05)., Results: BisCover had the lowest mean surface roughness (0.06 µm) compared with the sealants Fortify (0.09 µm) and Permaseal (0.08 µm), which were not statistically different. Fortify, at 12 months of brushing, had the highest mean roughness (0.13 µm). The mean roughness for the dentifrice CT was lower (0.07 µm) when compared with PW (0.08 µm) and was statistically different. Roughness increased up to 12 months of simulated brushing (0.04 µm, 0.08 µm and 0.11 µm), decreasing from the 18th month (0.08 µm) to the 24th month of brushing (0.07 µm). None of the sealants was observed (with SEM) to be completely removed from the resin at 24 months of brushing.

Purpose: To evaluate the effect of different bonding strategies on short- and long-term bis-GMA-based resin cement bond strengths to zirconia., Materials and Methods: One hundred twenty samples of fully-sintered zirconia (Prettau Zirconia) were sandblasted and randomly distributed into 5 groups (n = 24): UA: Scotchbond Universal Adhesive; SZP: Signum Zirconia Bond I + II; ZPP: Z-Prime Plus; EXP: MZ experimental primer; CO: no primer application (control). After performing these surface treatments, translucent tubes (0.8 mm diameter and 1.0 mm height) were placed on the zirconia specimens, and bis-GMA-based cement (Duo-Link) was injected into them and light cured. Specimens were tested for microshear bond strength either 24 h or 6 months (m) after water storage (37°C) and surfaces were characterized by SEM and EDX. Two-way ANOVA and Tukey's post-hoc test (p < 0.05) were used to evaluate bond strength results., Results: The mean bond strengths (MPa ± SD) were: UA=14.6 ± 4.7a (24 h); 16.0 ± 4.8a (6 m); SZP = 14.0 ± 5.4ab (24 h); 11.9 ± 2.6ab (6 m); ZPP=8.0 ± 1.8b (24 h); 8.6 ± 3.3b (6 m); EXP = 1.2 ± 0.5c (24 h); 0.6 ± 0.7c (6 m); CO=1.0 ± 1.2c (24 h); 1.3 ± 1.2c (6 m). Bonding strategy significantly influenced bond strength (p = 0.0001), but storage time did not (p = 0.841). Groups UA and SZP showed a homogeneous layer covering the zirconia surface. In these groups, EDX demonstrated the presence of phosphorus. Group ZPP resulted in a nonhomogeneous layer, exposing the zirconia substrate underneath. EXP application resulted in an undetectable layer., Conclusion: Water storage did not affect resin cement bond strengths to zirconia irrespective of the surface treatment. Bis-GMA-based resin cement bond strengths to zirconia are affected by specific bonding strategies.

Purpose: To clinically evaluate the performance of indirect composite resin restorations cemented with conventional and self-adhesive resin cements over a 12-month period., Materials and Methods: Ten patients fulfilled all the inclusion criteria. Twenty-four composite resin restorations were performed using an indirect technique and cemented with a resin cement (RelyX ARC) or a self-adhesive resin cement (RelyX U100). Two independent evaluators analyzed the restorations using modified USPHS criteria after periods of two weeks and 6 and 12 months. Statistical significance between the cements at each timepoint was evaluated with the Wilcoxon test and between timepoints with the Mann-Whitney test, both at a significance level of 5%. Fisher's exact test was used to assess the occurrence of absolute failures., Results: No statistically significant differences were found between the groups at the same timepoint nor between groups at different timepoints. The only significant difference was found for color match for both groups after 12 months., Conclusion: After 12 months, indirect composite resin restorations cemented with self-adhesive resin cement performed similarly to those cemented with conventional resin cement.

Background: Because no information was found in the dental literature regarding the fracture resistance of all-ceramic crowns using CEREC (Sirona) computer-aided design and computer-aided manufacturing (CAD-CAM) system on solid abutments, the authors conducted a study., Methods: Sixty synOcta (Straumann) implant replicas and regular neck solid abutments were embedded in acrylic resin and randomly assigned (n = 20 per group). Three types of ceramics were used: feldspathic, CEREC VITABLOCS Mark II (VITA); leucite, IPS Empress CAD (Ivoclar Vivadent); and lithium disilicate, IPS e.max CAD (Ivoclar Vivadent). The crowns were fabricated by the CEREC CAD-CAM system. After receiving glaze, the crowns were cemented with RelyX U200 (3M ESPE) resin cement under load of 1 kilogram. For each ceramic, one-half of the specimens were subjected to the fracture resistance testing in a universal testing machine with a crosshead speed of 1 millimeter per minute, and the other half were subjected to the fractured resistance testing after 1,000,000 cyclic fatigue loading at 100 newtons., Results: According to a 2-way analysis of variance, the interaction between the material and mechanical cycling was significant (P = .0001). According to a Tukey test (α = .05), the fracture resistance findings with or without cyclic fatigue loading were as follows, respectively: CEREC VITABLOCKS Mark II (405 N/454 N) was statistically lower than IPS Empress CAD (1169 N/1240 N) and IPS e.max CAD (1378 N/1025 N) (P < .05). The IPS Empress CAD and IPS e.max CAD did not differ statistically (P > .05). According to a t test, there was no statistical difference in the fracture resistance with and without cyclic fatigue loading for CEREC VITABLOCS Mark II and IPS Empress CAD (P > .05). For IPS e.max CAD, the fracture resistance without cyclic fatigue loading was statistically superior to that obtained with cyclic fatigue loading (P < .05)., Conclusions: The IPS Empress CAD and IPS e.max CAD showed higher fracture resistance compared with CEREC VITABLOCS Mark II. The cyclic fatigue loading negatively influenced only IPS e.max CAD., Practical Implications: The CEREC VITABLOCS Mark II, IPS Empress CAD, and IPS e.max CAD ceramic crowns cemented on solid abutments showed sufficient resistance to withstand normal chewing forces., (Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.)

Background: The aim of the study was to evaluate, in vitro, the surface roughness of two composite resins submitted to simulated toothbrushing with three different dentifrices., Materials and Methods: Totally, 36 samples of Z350XT and 36 samples of Empress Direct were built and randomly divided into three groups (n = 12) according to the dentifrice used (Oral-B Pro-Health Whitening [OBW], Colgate Sensitive Pro-Relief [CS], Colgate Total Clean Mint 12 [CT12]). The samples were submitted to 5,000, 10,000 or 20,000 cycles of simulated toothbrushing. After each simulated period, the surface roughness of the samples was measured using a roughness tester., Results: According to three-way analysis of variance, dentifrice (P = 0.044) and brushing time (P = 0.000) were significant. The composite resin was not significant (P = 0.381) and the interaction among the factors was not significant (P > 0.05). The mean values of the surface roughness (µm) followed by the same letter represent no statistical difference by Tukey's post-hoc test (P <0.05): Dentifrice: CT12 = 0.269(a); CS Pro- Relief = 0.300(ab); OBW = 0.390(b). Brushing time: Baseline = 0,046ª; 5,000 cycles = 0.297(b); 10,000 cycles = 0.354(b); 20,000 cycles = 0.584(c)., Conclusion: Z350 XT and Empress Direct presented similar surface roughness after all cycles of simulated toothbrushing. The higher the brushing time, the higher the surface roughness of composite resins. The dentifrice OBW caused a higher surface roughness in both composite resins.

Purpose: To assess the fracture strength of cavity preparations, directly restored with resin composite, with and without the presence of fiberglass posts with different diameters., Methods: 84 extracted third molars were embedded in acrylic resin and divided into six groups (n = 14 per group): healthy (H); cavity preparation (P); cavity preparation + endodontic treatment (PE); PE + resin composite (R); PE + R + 2 horizontally transfixed fiberglass posts 1.1 mm in diameter (PERP1); PE + R + 2 fiberglass posts 1.5 mm in diameter (PERP2). The MOD cavity preparations were standardized with their width corresponding to 2/3 of the buccolingual distance and occlusogingival depth of 4 mm, with 2 mm remaining above the cemento-enamel junction. Endodontic treatments were performed in the PE, R, PERP1 and PERP2 groups. The buccal surface received two demarcations to create orifices for placement of the PERP1 and PERP2 posts. Once the fiberglass posts were placed, the teeth were restored with resin composite. In group R, only resin composite was used. After 24 hours, the teeth were subjected to the fracture toughness test on a universal testing machine. A 10 KN load cell and crosshead speed of 1 mm/minute was used until fracture occurred. After testing, the teeth were inspected for the type of fracture classified as: pulpal floor fracture (AP) or cuspal fracture (CP)., Results: The data were subjected to ANOVA and Tukey's test (P < 0.05%), demonstrating a statistical difference between groups: H 3830NA; P 778ND; PE 572.93ND; R 1782NC; PERP1 2988NB; PERP2 3100NAB. The fracture pattern was similar between the tested groups, showing 50% of fracture for cusps and pulpal floor.

The aim of this study was to evaluate the influence of different resin cements on the cuspal deflection of endodontically treated teeth restored with composite resin inlays. Sixty upper premolars were randomly divided into five groups (n=12): 1 - sound teeth; 2 - cavity; 3 - Rely X ARC; 4 - RelyX Unicem; 5 - SeT. The teeth from groups 2, 3, 4 and 5 received a MOD preparation and endodontic treatment. Impressions were made with vinyl polysiloxane and poured using type IV die stone in groups 3, 4 and 5. Inlays with composite resin were built over each cast and luted with the resin cements. A 200 N load was applied on the occlusal surface, and cuspal deflection was measured using a micrometer. After 24 h, cuspal deflection was measured again using a 300 N load. The Student t-test showed that there was no statistically significant difference between the 200 N and 300 N occlusal loads only for the sound teeth group (p = 0.389) and the RelyX ARC group (p = 0.188). ANOVA and Tukey'test showed that the sound teeth had the lowest mean cuspal deflection, differing statistically from the other groups (p<0.05). The highest cuspal deflections were obtained in the SeT group and the cavity group, with no statistical difference between them. Intermediate values were obtained in RelyX ARC group and RelyX Unicem group, which differed statistically. The self-adhesive resin cements RelyX Unicem and SeT showed less capacity to maintain the stiffness of the tooth/restoration complex than the conventional resin cement RelyX ARC.

Statement of Problem: The optimum time after pouring a dental impression before removing the dental cast is unknown with regard to the strength and roughness of the stone. Setting times and the commercial products used are important variables., Purpose: The purpose of this study was to evaluate the effect of postpouring time on the surface roughness, compressive strength, and diametric tensile strength of Type IV dental stone., Material and Methods: A total of 270 specimens were prepared from 3 commercial brands of dental stone (Durone, Fuji Rock, and Tuff Rock). Surface roughness, compressive strength, and diametric tensile strength were assessed at 1 hour, 24 hours, and 7 days after pouring. Specimens 6 mm in diameter and 3 mm in height were produced for roughness and diametric tensile strength tests. Specimens 3 mm in diameter and 6 mm in height were used to measure compressive strength. The results were analyzed with the general linear model and Tukey honestly significant difference test (α=.05)., Results: The surface roughness measured for the different types of dental stone tested varied from 0.3 μm (Durone, 1 hour) to 0.64 μm (Tuff Rock, 7 days). The diametric tensile strength ranged from 3.94 MPa (Tuff Rock, 1 hour) to 9.20 MPa (Durone, 7 days). The compressive strength varied from 26.67 MPa (Durone, 1 hour) to 65.14 MPa (Fuji Rock, 7 days)., Conclusions: Surface roughness (P=.005), diametric tensile strength (P=.001), and compressive strength (P=.001) increased significantly with time after pouring. The commercial brand used affected roughness (P=.001), diametric tensile strength (P=.004), and compressive strength (P=.001). Tuff Rock exhibited the highest surface roughness. The highest diametric tensile strength values were recorded for Durone and Fuji Rock. Fuji Rock exhibited the highest compressive strength., (Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Background: This in situ study evaluated the roughness and microhardness of enamel bleached with 10% carbamide peroxide (PC10) and brushed with different toothpastes., Materials and Methods: Two groups of volunteers received PC10 and placebo agents for 21 days in two phases in a crossover 2 × 3 study. Fragments of human enamel were distributed among intraoral removable appliances (IRA). Nine fragments, divided into three triplets, were used in each IRA, and these were brushed with toothpastes R (Colgate), W (Colgate Total 12 Whiteness Gel) or BS (Colgate Whitening Oxygen Bubbles Fluoride). Treatments agents were applied for 8 h overnight. After brushing, the volunteers used the IRA for about 16 h/day. After a washout period, new IRAs were distributed and the volunteers were crossed over to the alternate agent for 21 days. Roughness and microhardness were measured before and after each phase., Results: According to the paired Student's t-test, roughness of enamel increased and microhardness decreased (P < 0.05). According to analysis of variance generalized linear models, only the toothpaste factor was significant (P = 0.037) for roughness., Conclusion: Enamel microhardness and surface roughness are altered when PC10 bleaching is associated with tooth brushing using toothpastes BS, R, and W.

Objectives: The objective of the following study is to evaluate the interaction between the resin materials used in immediate dentin sealing (IDS) techniques and impression materials with two different techniques to eliminate the oxygen-inhibition layer., Materials and Methods: The occlusal dentin surface of 35 human molars was exposed. The teeth were used in two Groups: Group 1 - Impression with Express XT; Group 2 - Impression with Impregum. Groups 1 and 2 were divided into 14 subgroups: Groups 1a and 2a - Control groups; 1b and 2b - IDS with Clearfil SE Bond (CSE); 1c and 2c - IDS with CSE + additional polymerization with glycerin jelly; 1d and 2d - IDS with CSE + alcohol; 1e and 2e - IDS with CSE and Protect Liner F (PLF); 1f and 2f - IDS with CSE and PLF + additional polymerization with glycerin jelly; and 1g and 2g - IDS with CSE and PLF + alcohol. Five teeth were used in each experimental group, and the tooth surface was photographed using a digital camera., Results: Small quantity of unpolymerized impression material remained attached to the CSE or to the PLF in Groups 1b and 1e. Groups 1c and 1d prevented the interaction. Small quantity of polymerized impression material remained attached to the CSE or to the PLF for Groups 2b and 2e. The same interaction was observed for Groups 2c and 2d. For Groups 2c and 2f, no interactions were observed., Conclusion: Resin materials interacted with impression materials. The application of glycerin jelly and alcohol prevented the interaction of CSE with Express XT and PLF with Impregum; however, these treatments were not completely effective in preventing the interaction of CSE with Impregum and PLF with Express XT.

Background: This study evaluated in vivo the accuracy of metal (Smart®) and plastic (Triple Tray®) dual-arch trays used with vinyl polysiloxane (Flexitime®), in the putty/wash viscosity, as well as polyether (Impregum Soft®) in the regular viscosity., Materials and Methods: In one patient, an implant-level transfer was screwed on an implant in the mandibular right first molar, serving as a pattern. Ten impressions were made with each tray and impression material. The impressions were poured with Type IV gypsum. The width and height of the pattern and casts were measured in a profile projector (Nikon). The results were submitted to Student's t-test for one sample (α = 0.05)., Results: For the width distance, the plastic dual-arch trays with vinyl polysiloxane (4.513 mm) and with polyether (4.531 mm) were statistically wider than the pattern (4.489 mm). The metal dual-arch tray with vinyl polysiloxane (4.504 mm) and with polyether (4.500 mm) did not differ statistically from the pattern. For the height distance, only the metal dual-arch tray with polyether (2.253 mm) differed statistically from the pattern (2.310 mm)., Conclusion: The metal dual-arch tray with vinyl polysiloxane, in the putty/wash viscosities, reproduced casts with less distortion in comparison with the same technique with the plastic dual-arch tray. The plastic or metal dual-arch trays with polyether reproduced cast with greater distortion. How to cite the article: Santayana de Lima LM, Borges GA, Burnett LH Jr, Spohr AM. In vivo study of the accuracy of dual-arch impressions. J Int Oral Health 2014;6(3):50-5.

Purpose: To evaluate the influence of resin cements and aging on cuspal deflection, fracture resistance, and mode of failure of endodontically treated teeth restored with composite resin inlays., Materials and Methods: Seventy-two maxillary premolars were divided into 6 groups: 1: sound teeth as control (C); 2: preparations without restoration (WR); 3: inlays luted with RelyX ARC (ARC); 4: inlays luted with RelyX Unicem (RLXU); 5: inlays luted with Maxcem Elite (MCE); 6: inlays luted with SeT (ST). Groups 2 to 6 received mesio-occlusal-distal preparations and endodontic treatment. Stone casts were made for groups 3 to 6. Composite resin inlays were built over each cast and luted with the resin cements. A 200-N load was applied on the occlusal aspect and the cuspal deflection was measured using a micrometer before and after 500,000 cycles of fatigue loading (200 N; 500,000 cycles). The specimens were then submitted to an axial load until failure., Results: The median cuspal deflection (µm) and median fracture resistance (N) were calculated and statistically analyzed using Kruskal-Wallis and Mann-Whitney tests (p < 0.01). Values followed by the same letter represent no statistically significant difference. Cuspal deflection before cyclic loading: C = 3 µma; ARC = 4 µmab; RLXU= 5 µmab; MCE = 21 µmb; ST = 51 µmbc; WR = 69 µmc. Cuspal deflection after cyclic loading: ARC = 6 µma; RLXU = 19 µmab; MCE = 33 µmb; ST = 62 µmb. Fracture resistance in N: C = 1902a; ARC = 980b; RLXU = 670c; MCE = 533c; ST = 601c; WR = 526c. According to the Wilcoxon test, there was no statistical difference between the cuspal deflection before and after cyclic loading only for ARC (p = 0.015). There was a predominance of recovery fractures for the restored groups., Conclusion: Composite resin inlays luted with RelyX ARC maintained cuspal deflection stability and showed higher fracture resistance of the teeth than did inlays luted with the other cements tested.

Objectives: The objective of this study is to evaluate, in vitro, the thickness of immediate dentin sealing (IDS) materials on full crown preparations and its effect on the fracture load of a reinforced all-ceramic crown., Materials and Methods: SIXTY PREMOLARS RECEIVED FULL CROWN PREPARATION AND WERE DIVIDED INTO THE FOLLOWING GROUPS ACCORDING TO THE IDS TECHNIQUE: G1-control; G2-Clearfil SE Bond; and G3-Clearfil SE Bond and Protect Liner F. After the impressions were taken, the preparations were temporized with acrylic resin crowns. IPS empress 2 restorations were fabricated and later cemented on the preparations with Panavia F. 10 specimens from each group were submitted to fracture load testing. The other 10 specimens were sectioned buccolingually before the thicknesses of Panavia F, Clearfil SE Bond and Protect Liner F were measured in 10 different positions using a microscope., Results: According to analysis of variance and Tukey's test, the fracture load of Group 3 (1300 N) was significantly higher than that of Group 1 (1001 N) (P < 0.01). Group 2 (1189 N) was not significantly different from Groups 1 and 3. The higher thickness of Clearfil SE Bond was obtained in the concave part of the preparation. Protect Liner F presented a more uniform range of values at different positions. The thickness of Panavia F was higher in the occlusal portion of the preparation., Conclusions: The film thickness formed by the IDS materials is influenced by the position under the crown, suggesting its potential to increase the fracture load of the IPS empress 2 ceramic crowns.