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The esthetic treatment of anterior teeth with porcelain veneers is a conservative and lasting treatment option. When the tooth is severely discolored, the clinician must choose a ceramic system very carefully, because translucent materials, such as hot-pressed ceramic, require excessive reduction of the dental structure to mask the discoloration. This article describes a technique in which discolored teeth were masked in a conservative and esthetically pleasing way with feldspathic porcelain veneers. [ABSTRACT FROM AUTHOR]

This in situ study evaluated the influence of two home-use tooth bleaching regimes (1 hour/day and 7 hours/day) using 10% carbamide peroxide (Nite White Excel 2Z) on the surface microhardness of dentin over a 21-day period. Nine blocks of dentin derived from the teeth of subjects, each with at least two thirds molar in need of extraction, were obtained from the cervical region and submitted to surface-hardness analysis (Shimadsu HMV/2000), fixed to an intraoral palate device fabricated for each subject, and positioned (3 left side, 3 right side, 3 center) according to experimental group. During the bleaching period, casts bearing the whitening agent were applied to the blocks for 7, 1, and 0 hours, respectively (7 left side, 3 right side, 0 center). After the treatment period, the specimens were once again submitted to microhardness analysis, using the same equipment as before, and then analysis of variance and the Scheffé test were applied to the mean differences between the initial and final evaluations. The results demonstrated that the statistical difference between the 1-hour and 7-hour groups was not significant. However, the 7-hour group, when compared with the control group, demonstrated statistically significant differences with a reduction in microhardness. Despite the occurrence of mineral loss in the 1-hour and 7-hour groups, this difference was only 3.1% and 5.4%, respectively, which allows one to conclude that these values probably have no clinical significance. [ABSTRACT FROM AUTHOR]

Coronal fractures must be approached in a methodical and clinically indicated way to achieve successful restoration. One option for treatment is reattachment of the dental fragment. Reattachment creates a very positive emotional response in the patient and simplifies the maintenance of the patient's original occlusion. This article discusses dental fragment reattachment techniques and presents clinical cases of coronal fracture involving enamel, dentin, and pulpal exposure. [ABSTRACT FROM AUTHOR]

A technique for manufacturing direct resin composite veneers is presented. Described are the advantages of using an acrylic resin matrix, made before the preparation is begun, to copy anatomic details. An additional step to mask previously prepared dark enamel with opaquers is also described. The advantages and limitations of the procedures are discussed. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The purpose of this project was to evaluate the performance of a dentin adhesive system on carious and noncarious primary dentin in vivo. METHOD AND MATERIALS: Forty-eight primary molars with carious lesions were randomly assigned to 2 different treatments: group 1 (control, n = 24)--All identifiable, irreversibly infected dentin was removed prior to the application of the bonding agent and restorative material; group 2 (experimental, n = 24)--Irreversibly infected dentin was partially removed prior to the application of the bonding agent and restorative material. The control and experimental teeth were clinically monitored every 3 months and evaluated 12 months after restoration. The teeth were extracted around the time of exfoliation and processed for scanning electron microscopy. RESULTS: Retention rate, marginal integrity, and pulpal symptoms were identical in both groups. Radiographically, the radiolucent area associated with the experimental restorations did not increase with time in 75% of the cases. For the control group, the adhesive system formed a hybrid layer. In the experimental group, there was morphologic evidence of the formation of an acid-resistant 'altered hybrid layer.' An acid-resistant tissue, resulting from the interdiffusion of adhesive resin within the area of carious dentin, was observed adjacent to and under the altered hybrid layer. CONCLUSION: Application of an adhesive restorative system to irreversibly infected dentin did not affect the clinical performance of the restoration. [ABSTRACT FROM AUTHOR]

This study compared the shear bond strengths (SBS) to dentin achieved with six self-etching systems and one total-etch one-bottle adhesive system. Seventy freshly extracted bovine incisors were mounted in acrylic molds and the facial surfaces ground to expose middle dentin, which was polished by 600-grit sand paper. The incisors were randomly assigned to groups (n=10): Adper Prompt Self-Etch Adhesive, 3M-ESPE (ADP) and One-Up Bond F, Tokuyama (OU) as self-etching adhesives; AdheSE, Ivoclar-Vivadent (ADH), Clearfil SE Bond, Kuraray (SE), Optibond Solo Plus-Self-Etch, Kerr (OP) as self-etching primers, Tyrian SPE, BISCO (TY) as a self-priming etchant and Single Bond, 3M-ESPE (SB), a total-etch one-bottle adhesive served as a control. All adhesives were applied according to the manufacturers' instructions with the respective hybrid composites. The specimens were thermocycled for 500 cycles (5°C to 55°C), then loaded to failure in an Instron Universal Testing Machine at a crosshead speed of 0.5 mm/minute. Mean bond strengths were analyzed with one-way ANOVA, followed by a Duncan's post hoc test. SBS (mean ±SD) were: ADH = 13.2 (±5.3)b ADP = 6.8 (±4A)c OP = 18.2 (±3.8)a OU = 3.5 (±1.5)c SB = 12.2 (±4.2)b SE = 12.4 (±4.0)b TY = 5.5 (±1.4)c. Superscript letters indicate Duncan's homogeneous subsets. The self-etching adhesives OU and ADP and the self-priming etchant TY resulted in lower dentin SBS. OP resulted in the highest mean dentin SBS, while the other materials tested in this study (SE and ADH) presented similar dentin SBS to a total-etch one-bottle bonding system (SB). [ABSTRACT FROM AUTHOR]

This study compared the shear bond strength (SBS) to enamel of five self-etching primer/adhesive systems and one total-etch, one-bottle adhesive system. Sixty freshly extracted bovine incidence were mounted, polished to 600-grit and randomly assigned to six groups (n=10): Adper Prompt Self-Etch (AD), OptiBond Solo Plus Self-Etch (OP), AdheSE (AS), Tyrian (TY) and Clearfil SE Bond (SE) as self-etching systems; and Single Bond (SB) as a total-etch system (control). The respective hybrid composite was applied in a #5 gelatin capsule and light-cured. After 500 thermal cycles (5°C-55°C), the specimens were loaded in shear using an Instron at 5 mm/minute. Mean bond strengths were analyzed with one-way ANOVA, followed by a Duncan's post-hoc test (p 0.05). SBS (mean ± SD) were: AD=13.0(±2.5); OP=5.6(±2.3); AS=12.6(±3.7); TY=7.6(±2.6); SE=17.6(±4.5) and SB=17.9(±4.4). ANOVA showed a significant difference at p<0.0001. Duncan's post-hoc test ranked this difference in three homogeneous subsets. Only SE showed similar enamel SBS compared to the total-etch system tested (SB). AD and AS were ranked in the intermediary Duncan's subset, while TY and OP resulted in the lowest SBS. SBS to enamel with self-etching primers may depend on its specific composition. [ABSTRACT FROM AUTHOR]

Objective: Comparison of soft tissue replication between conventional and digital impressions for definitive single unit implant rehabilitation in the esthetic zone., Materials and Methods: Six patients were recruited according to inclusion criteria for this cross-over pilot study and submitted to a conventional silicone implant impression with customized coping and a digital impression with an intraoral scanner. Stereolithography files obtained from the same patient were superimposed with appropriate software and trueness evaluated between methods at predetermined locations (56 in hard and soft tissues and 18 in the emergence profile, per patient). Results were presented as mean root mean square (RMS) ± 95% confidence interval and effect size calculated with Hedges' g ± 95%. Mann-Whitney and Kruskal-Wallis were performed when appropriate and α was set at .05., Results: Trueness between methods equated to 51.08[45.68;56.47] μm and 60.46[52.29;68.62] μm in hard and soft tissues, respectively. Soft tissue replication by intraoral scanner acquisition corresponded to a statistically significant RMS of 243.89[209.15;278.63] μm equating to a Hedges' g of 1.52[1.22;1.82] which corresponded to a large effect size., Conclusions: The proposed method could be considered for soft tissues assessment and the results suggest that intraoral impression techniques produce statistically significant changes in peri-implant soft tissue replication, although below the clinically detectable threshold., Clinical Significance: The proposed technique allows for the 3D determination of peri-implant tissues changes in digital models with higher sensitivity than visual techniques, thus presenting itself as a promising alternative in clinical studies and that the use of an intraoral scanner obtained significant differences in the soft tissue emergence profile replication when compared with the gold standard., (© 2019 Wiley Periodicals, Inc.)

The aim of this study was to evaluate whether the compressive strength of lithium dissilicate ceramic inlays is influenced by the substrate (dentin or composite resin build-up) and to compare it to nonrestored teeth. Thirty freshly extracted human maxillary third molars were selected and randomly ascribed to three groups (n=10). Standardized Class II MOD preparations were made (bucco-palatal width = 2/3 of the intercuspal width and 2/3 of the width at the tooth equator for the proximal boxes), varying the extension of the preparations (Group 2: preparation limited to tooth structure; Group 3: pulpal floor of the preparation rebuilt with composite resin, IPS Empress Direct, restored with lithium dissilicate CAD/CAM ceramic inlays (e.max CAD) and cemented with a resin cement (Variolink II)). All groups were subjected to compressive strength test (1mm/min crosshead speed). The results showed that the fracture strength of G1 (control group) was significantly higher than G2 and G3, while within these groups there were no statistically significant differences. Both groups restored with lithium dissilicate restorations did not reach the fracture strength of the sound teeth but were statistically equivalent and sufficient to withstand physiologic masticatory forces.

Context: Studies have been conducted to measure the fracture resistance of restored teeth with the current restorative materials. However, most of those studies disregard the cavity size as an influencing variable., Aims: To evaluate the fracture resistance of prepared and restored maxillary premolars with medium and large preparations., Materials and Methods: Seventy superior and sound premolars were randomly divided: G1 (control) - sound tooth; G2, G3, and G4 received a Class II mesial-occlusal-distal (MOD) preparation with an occlusal box width 1/3 of the intercuspal distance, and were restored with Filtek Z350 XT, IPS Empress Direct, and Charisma Diamond, respectively; G5, G6, and G7 received a Class II MOD preparation with an occlusal box width 2/3 of the intercuspal distance, and were restored with Filtek Z350 XT, IPS Empress Direct, and Charisma Diamond, respectively. After storage in water, at 37°C, the specimens were subjected to a fracture test under compression in a universal testing machine where the loads were applied vertically and at a speed of 0.5 mm/min., Statistical Analysis Used: Data were analyzed with two-way ANOVA and Tukey's multiple comparison post hoc test (P < 0.05)., Results: G1 presented a fracture resistance significantly higher (P = 0.005) than any other experimental groups. Among the experimental groups, only G5 showed a significantly low fracture resistance (P = 0.019) when compared to the other groups. For the other resins, the change in intercuspal distance from 1/3 to 2/3 the intercuspal distance did not significantly reduce the fracture resistance (P > 0.05)., Conclusions: The cavity preparation weakens the remaining tooth structure; however, its resistance could be partially restored using direct adhesive restorations., Competing Interests: There are no conflicts of interest

Objective: The treatment of fractured teeth has become a great opportunity to investigate new approaches in the field of restorative dentistry. Restoring teeth with ceramic fragments is a great challenge, however, the computer aided design/computer aided manufacturing (CAD/CAM) technology allows the fabrication of both laminate veneers and ceramic fragments., Materials and Methods: Thus, the aim of this article was to report a clinical case where anterior teeth, fractured due to a sport practice, were restored with CAD/CAM ceramic fragments., Conclusions: It was observed that with this kind of restoration optimum esthetic results might be achieved when treating anterior fractured teeth., Clinical Significance: Ceramic fragments using CAD/CAM systems are a viable clinical alternative to composites for the reconstruction of fractured teeth. Function and esthetics can be restored with the use of this treatment quickly and efficiently., (© 2017 Wiley Periodicals, Inc.)

Statement of Problem: Controlled clinical trials comparing the effectiveness of the walking bleaching (WB) technique and the inside-outside (I-O) technique used in a short daily regimen are lacking., Purpose: The purpose of this randomized clinical trial was to investigate the effectiveness of WB with that of the I-O technique conducted over 4 weeks and to compare color changes after 1 year., Material and Methods: Discolored and endodontically treated anterior teeth received a cervical seal and were randomly divided into groups according to the technique. In the WB group (n=9), a mixture of sodium perborate and 20% hydrogen peroxide was applied in the pulp chambers and replaced weekly up to 4 weeks. For the I-O group (n=8), participants applied 10% carbamide peroxide in the pulp chambers and wore custom-fitted trays for 1 hour per day over 4 weeks. CIELab parameters were obtained using a spectrophotometer at baseline, during bleaching (1, 2, 3, and 4 weeks) and after 1 year. Changes in color (ΔE), lightness (ΔL*), green-red axis (Δa*), blue-yellow axis (Δb*), and absolute color parameters (L*, b*, and a*) for each evaluation time were calculated and analyzed by repeated measures analysis of variance (ANOVA) and post hoc Bonferroni test (α=.05)., Results: No significant differences between WB and I-O techniques were observed for ΔE, ΔL*, Δa*, Δb*, L*, a*, or b* values (P>.05); however, significant differences were observed among the evaluation times (P<.05). Color changes observed after 2 weeks were stable after 1 year; ΔL* and Δa* values after 1 year were not significantly different from the 1-week evaluation, and significant changes in Δb* after 3 weeks were maintained at the 1-year follow-up. The same trend was observed for the absolute CIELab color parameters., Conclusions: Both WB and I-O regimens were similarly effective as shown by significant ΔE after 2 weeks and no color regression after 1 year., (Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Objective: This study aimed to evaluate the ability of the proposed technique in producing restorations that exhibit mimesis with tooth structure and to define a restorative clinical protocol., Materials and Methods: For this study a typodont was used. The right upper central incisor with Class IV lesion was restored with the layering technique (reference tooth, RT). For the left upper central incisor with Class IV lesion, six teeth were restored monochromatically (test teeth, TT), using DA3.5 (n = 3) and DA4 (n = 3) composite resins-resulting in six unsatisfactory color restorations. TT were divided into six groups depending on the color of unsatisfactory restoration and preparation depth. First, a preparation was realized on the labial surface with 0.5 mm, 0.7 mm or 1.0 mm of depth. A second preparation was then performed to reproduce the dentinal mamelons. Next, adhesive procedures were performed and the teeth restored. Opaque halo, opalescent halo and vestibular enamel were then reproduced by the addition of different composite resins. The RT and TT were photographed side by side in typodont to obtain six photographic prints. The photographs of the groups were subjected to visual evaluation by 120 volunteers via a questionnaire. Data were analyzed by the prevalence of answers, and Chi-square test was used to investigate the association between variables at .05 significance. Furthermore, ΔE of groups was evaluated in comparison RT., Results: The results demonstrated that the moderate intensity restorations (DA3.5) with depths of 0.5 mm and 0.7 mm had the highest prevalence of acceptance. For severe intensity restorations (DA4), the preparation depth of 1.0 mm obtained better acceptance., Conclusions: The technique was able to modify the final color of Class IV restorations, producing satisfactory color restorations., Clinical Significance: This technique can be used for color correction in cases of Class IV restorations, in situations where there is no time for immediate layered restoration, and as a restorative technique., (© 2017 Wiley Periodicals, Inc.)

The polishing step of teeth preparations for crowns is a step often performed, so that there is an increased time during the clinical procedure. The aim of this study is to evaluate the marginal and internal adaptation of all-ceramic CAD/CAM lithium disilicate crowns in polished preparations for crown and nonpolished preparations for crowns. For this purpose, 20 first molars were selected, which were divided into two groups ( n = 10) G1, teeth that received surface roughening similar to preparation without polishing, and G2 (control), polished preparations. After the preparations were completed the teeth were scanned (Cerec Bluecam, Sirona, Bensheim, Germany), and the crowns were designed and machined using CAD/CAM technology (Sirona, Bensheim, Germany). The adaptation of the pieces was evaluated using polyvinyl siloxane replicas and stereomicroscope photographs with 70x magnifications. The normality test indicated a nonnormal result, so a Man-Whitney nonparametric test was performed. One out of the 24 measured regions showed a statistically significant difference ( p = 0.0494). With this study it can be concluded that crowns fabricated by CAD/CAM technology performed on unpolished preparations are not influenced by the internal marginal adaptation and the ceramic part and are different from polished preparations.

Statement of Problem: The influence of different compositions of desensitizing agents in whitening gels should be evaluated., Purpose: The purpose of this clinical trial was to compare the effectiveness of 4 carbamide peroxide (CP)-based bleaching gels containing desensitizing agents regarding the degree of bleaching, tooth sensitivity, degree of participant satisfaction, and gingival irritation., Material and Methods: The maxillary arch of the 50 participants was bleached using a split mouth, home-bleaching technique. The participants were divided into 2 groups: G1, 10% CP (Opalescence PF; Ultradent Products, Inc) (right) and 10% CP (Power Bleaching 10%; BM4) (left); and G2, 15% CP (Opalescence PF) (right) and 16% CP (Power Bleaching 16%) (left). Each gel was used in a 2-hour daily regimen for 45 days. The shade of the 6 maxillary anterior teeth was recorded with a shade guide and spectrophotometer at baseline, and after 15, 30, 45, and 180 days of treatment. Statistical differences were analyzed with ANOVA for repeated measures followed by the Bonferroni and Student t tests (α=.05). Tooth sensitivity was evaluated with a visual analog scale (rated on a 0 to 10 scale). Participant satisfaction was evaluated by using participant reports of their personal satisfaction or dissatisfaction with the shade. Gingival irritation was evaluated using the Löe index scores., Results: Color change was found to be statistically significant for all treatment periods evaluated, both by the objective and the subjective analyses, regardless of the composition and the concentration of the bleaching agent (P<.001). After 45 days, all participants were satisfied with the shade obtained. No clinically diagnosed gingival irritation was noted. Neither of the 10% CP products caused sensitivity during treatment, and 16% CP containing 3% potassium oxalate showed lower sensitivity than 15% CP containing potassium nitrate., Conclusion: The association of 3% potassium oxalate with fluoride was effective in reducing tooth sensitivity during and after bleaching, particularly with the 16% CP product, and did not compromise the effectiveness of treatment., (Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

The purpose of this study was to evaluate the µTBS (microtensile bond strength) of currently available self-etching adhesives with an experimental self-etch adhesive in normal and caries-affected dentin, using a portable hardness measuring device, in order to standardize dentin Knoop hardness. Normal (ND) and caries-affected dentin (CAD) were obtained from twenty human molars with class II natural caries. The following adhesive systems were tested: Mega Bond (MB), a 2-step self-etching adhesive; MTB-200 (MTB), an experimental 1-step self-etching adhesive (1-SEA), and two commercially available one-step self-etching systems, G-Bond Plus (GB) and Adper Easy Bond (EB). MB-ND achieved the highest µTBS (p<0.05). The mean µTBS was statistically lower in CAD than in ND for all adhesives tested (p<0.05), and the 2-step self-etch adhesive achieved better overall performance than the 1-step self-etch adhesives.

Statement of the Problem: There are different approaches and treatment times to achieve tooth whitening., Purpose: The purpose of this study was to evaluate the efficacy of different agents and the treatment time required to achieve participant satisfaction with at-home and in-office tooth whitening., Material and Methods: Thirty participants were selected based on the shade of the anterior teeth (between A2 and A3.5; Vita Classic Shade Guide). Each participant received both in-office and at-home bleaching agents in a split-mouth design at both arches. In-office bleaching was performed in the maxillary quadrants, applying 35% hydrogen peroxide (HP35%) (right) and 35% HP with calcium (HP35%Ca) (left) for 40 minutes/week. Home bleaching was performed in mandibular quadrants using carbamide peroxide 10% (CP10%) (right) and CP22% (left) for 2 hours/day. Bleaching treatments were performed until participant satisfaction was achieved (maximum 6 sessions [S] in the dental office or 6 weeks [W] in the home). The shade was measured with a spectrophotometer before treatment, then at 2 and 4 weeks, and at the last week for at-home bleaching; and 1 week after the second, fourth, and last sessions for in-office bleaching. Student t and Tukey-Kramer tests were used (α=.05)., Results: All bleaching agents were effective for vital tooth whitening. No significant differences were observed for color changes between CP10% and CP22% or between HP35% and HP35%Ca for all periods. Treatment times required to achieve patient satisfaction for the in-office bleaching technique were 4S (12 participants), 5S (10 participants), and 6S (8 participants); and 4W (6 participants), 5W (8 participants), and 6W (16 participants) for the at-home bleaching technique., Conclusions: Treatment time to participant satisfaction ranged from 4 to 6 weeks regardless of the bleaching agent used in at-home and in-office therapy., (Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Aim: The aim of this study was to evaluate the influence of the subject's age and dentin etching time on the clinical performance of a two-step etch-and-rinse adhesive in class V non-carious cervical lesions (NCCLs)., Materials and Methods: Forty patients with NCCLs (classified as degrees 2 and 3 of dentin sclerosis) were enrolled in this study. The lesions were selected and assigned into two groups (n = 70/group) according to the subject's age: (G1) between 21-35 years old and (G2) between 40-54 years old. Each group was randomly divided into two subgroups (n = 35/group) according to dentin etching time using recommended application time (15 s) and an extended application time (30 s). A total of 140 restorations with XP Bond (Dentsply DeTrey, Germany) were placed. The composite resin Esthet X (Dentsply) was placed incrementally. All restorations were evaluated using the modified USPHS criteria. Data was analyzed by the McNemar and chi-square tests (p < 0.05)., Results: At the end of 2 years, 132 restorations (94.2% recall rate) were evaluated. The 24-month retention rates (%) were 93.5 for G1(15), 97.1 for G1(30), 93.9 for G2(15), and 97.0 for G2(30). There were no statistical differences in the retention rates in each recall period among groups., Conclusion: For the selected age groups, neither the subject's age nor the etching time had any influence on the clinical performance of XP Bond adhesive in NCCLs over a 24-month period., Clinical Relevance: The clinical effectiveness of the XP Bond was excellent after 2 years of clinical service. Long-term clinical evaluations are necessary to confirm this finding.

The purpose of this study was to determine the effect of cavity depth, ceramic thickness, and resin bases with different elastic modulus on von Mises stress patterns of ceramic inlays. Tridimensional geometric models were developed with SolidWorks image software. The differences between the models were: depth of pulpal wall, ceramic thickness, and presence of composite bases with different thickness and elastic modulus. The geometric models were constrained at the proximal surfaces and base of maxillary bone. A load of 100 N was applied. The stress distribution pattern was analyzed with von Mises stress diagrams. The maximum von Mises stress values ranged from 176 MPa to 263 MPa and varied among the 3D-models. The highest von Mises stress value was found on models with 1-mm-thick composite resin base and 1-mm-thick ceramic inlay. Intermediate values (249-250 MPa) occurred on models with 2-mm-thick composite resin base and 1-mm-thick ceramic inlay and 1-mm-thick composite resin base and 2-mm-thick ceramic inlay. The lowest values were observed on models restored exclusively with ceramic inlay (176 MPa to 182 MPa). It was found that thicker inlays distribute stress more favorably and bases with low elastic modulus increase stress concentrations on the internal surface of the ceramic inlay. The increase of ceramic thickness tends to present more favorable stress distribution, especially when bonded directly onto the cavity without the use of supporting materials. When the use of a composite base is required, composite resin with high elastic modulus and reduced thickness should be preferred.

The purpose of this study was to evaluate the influence of buccal and lingual wall thickness on the fatigue resistance of molars restored with CAD/CAM ceramic inlays. Forty human third molars were selected and divided into 4 groups, according to the remaining surrounding wall thickness chosen for inlay preparation (n=10): G1, 2.0 mm; G2, 1.5 mm; G3, 1.0 mm; G4, 0.5 mm. All inlays were made from feldspathic ceramic blocks by a CAD/CAM system, and cemented adhesively. After 1 week stored in distilled water at 37 °C, the specimens were subjected to fatigue testing under the following protocol: 5Hz; pre-load of 200 N for 5,000 cycles, followed by increasing loads of 400, 600, 800, 1000, 1200 and 1400 N for 30,000 cycles each. The specimens were cycled until failure or completion of 185,000 cycles. The survival rate of the groups was compared using the Kaplan-Meier survival curves (p>0.05). All specimens withstood the fatigue protocol (185,000 cycles), representing a 100% survival rate. The Kaplan-Meier survival curves showed no difference between groups. It can be concluded that the remaining tooth wall thickness did not influence the fatigue resistance of molars restored with CAD/CAM ceramic inlays.

Silorane-based composite resin requires a specific adhesive system: a 2-step self-etching adhesive. Clinical protocols are well established and are based on the principles of adhesion to mineralized dental tissues. In this paper, we present a clinical application of the silorane adhesive system in a class-II restoration using silorane-based composite resin.

Objectives: The purposes of this study were to investigate the effects of thermal residual stresses on the reliability and lifetime of zirconia-veneer crowns., Methods: One hundred and twenty eight second upper premolar zirconia-veneer crowns were manufactured for testing the initial strength (n=64) and under cyclic fatigue (n=64). Zirconia copings (YZ Cubes, VITA Zahnfabrik, CTE: alphac=10.5 ppm/°C) were milled using a Cerec3 InLab (Sirona) machine and sintered to a final thickness of 0.7 mm. Sixty-four copings were sandblasted with 105 μm alumina particles (15 s, 3 cm distance, 45° angle, 0.4 MPa pressure) in order to trigger a tetragonalmonoclinic transformation and to produce a rough surface. The copings were veneered using two different porcelains (VM9, VITA Zahnfabrik, CTE: alphaVM9=9.1 ppm/°C, Lava Ceram, 3M ESPE, CTE: alphaLava=10.2 ppm/°C) so to result in crowns with either high thermal mismatch (+1.4 ppm/°C with VM9) and low thermal mismatch (+0.3 ppm/°C with Lava Ceram). The porcelains were applied by the same operator and fired (VITA Vacumat 4000) according to the firing schedules defined by the manufacturers to a final thickness of 1.4mm (total crown thickness=2.1mm, core/veneer ratio=0.5). After the last glaze firing the crowns were cooled following a fast (600°C/min) or a slow (30°C/min) cooling protocol. The glazed crowns were submitted to a sliding-motion (0.7 mm lateral movement) cyclic fatigue in a chewing simulator (SD Mechatronik) under 20 kg (~200 N load) weight until failure (chipping) (n=16). The other half of the crowns were subjected to a compressive loading test in an universal testing machine (Instron model 4240) until failure at a cross-head speed of 0.75 mm/min (n=16). The failure probability for initial strength and cyclic fatigue was performed using a Weibull distribution approach at a scale factor of n=16., Results: The compressive strength test showed a low sensitivity to detect reliability variations regarding thermal stresses created within the veneer layer of tested crowns. For cyclic fatigue, slow cooling resulted in statistically higher cycles to failure only for the crowns that presented a high thermal mismatch between core and veneer (VM9 group). Comparisons between veneers with high or low thermal mismatches showed statistically higher sigma0 for Lava Ceram-veneered crowns only when the groups were fast-cooled., Significance: Minimizing the thermal residual stresses within the veneer through the use of a veneer with a closer CTE to the zirconia delays the failure of zirconia-veneer crowns. Slow-cooling increases the lifetime of crowns presenting large differences in CTE between the zirconia core and the veneering porcelain., (Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Objectives: To evaluate the influence of tooth bleaching on the opalescence properties of enamel., Methods: Color of 38 specimens was determined by colorimetric analysis before and after bleaching in the reflectance and transmittance modes. The results were described as CIELab color coordinates. The Opalescent Parameter (OP) was calculated as the difference in yellow-blue color coordinate (CIE Δb*) and red-green color coordinate (CIE Δa*) between the reflected and transmitted colors., Results: Mean OP value of the specimens was 18.9 (±1.6) before bleaching and 16.1 (±1.0) after bleaching., Conclusions: Bleaching decreases the OP of the specimens (p>0.001). OP decrease was correlated with differences in b* color coordinate in the transmittance mode., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The aim of this research is to evaluate bond strength between translucent fibre posts (White Post DC, FGM or FRC Postec Plus, Ivoclar/Vivadent) and intraradicular dentin at three different levels (cervical, middle and apical) using a dual-cure (AllCem, FGM) or self-curing (Multilink, Ivoclar/Vivadent) resin cement. Also, the fracture type after push-out test was analysed under SEM. Thirty-two extracted single-root teeth were selected. After undergoing endodontic therapy, they were randomly divided into four groups according to their post type and resin cement. Root canals were etched using 37% phosphoric acid, and Excite DSC adhesive (Ivoclar/Vivadent) was applied in all groups. The root was sectioned to obtain nine 1-mm-thick slices (three per third: coronal, middle, apical). All slices were subjected to push-out tests. Data were analysed using two-way anova. The mean bond strengths vary from 6.6 (4.6) MPa [apical] to 11.9 (5.9) MPa [cervical]. There were no significant differences between groups. Pearson χ(2)-test revealed significant differences in fracture types for all groups (P < 0.0001). The apical third had the lowest bond strengths and it was also shown to be the most critical region for luting fibre posts., (© 2010 The Authors. Australian Endodontic Journal © 2010 Australian Society of Endodontology.)

Residual stresses within the veneer are linked to the high prevalence of veneer chipping observed in clinical trials of zirconia prostheses. We hypothesized that the thermal mismatch between the zirconia infrastructure and the veneer porcelain, as well as the rate used for cooling zirconia-veneer crowns, would be directly proportional to the magnitude of residual stresses built within the veneer layer. Two porcelains with different coefficients of thermal expansion were used to veneer zirconia copings, to create high or low thermal mismatches. The crowns were cooled according to a fast- or a slow-cooling protocol. The retardation of polarized light waves was used to calculate the residual stress magnitude and distribution across the veneer, according to the photoelasticity principle, in 1.0-mm-thick crown sections. While thermal mismatch was an important factor influencing the maximum stress development in the veneer, cooling rate had a minor role. Curved surfaces were preferential sites for stress concentration regardless of thermal mismatch or cooling rate.

Purpose: To evaluate the effect on bond strength of 1, 2, or 3 coats of two one-step self-etching adhesives on dentin covered with two different smear layer thicknesses., Materials and Methods: Flat dentin surfaces from recently extracted third molars were wet ground with 60- or 600-grit SiC paper to produce smear layers of different thicknesses. Adper Easy Bond (3M ESPE) and Clearfil S3 Bond (Kuraray) were applied in 1, 2, or 3 consecutive coats after air drying each coat. ScotchBond Multi Purpose (3M) and Clearfil SE Bond (Kuraray) were used as controls. Composite resin crowns (Filtek Z250, 3M ESPE) were built up, stored for 24 h, and cut in x and y directions. Eight to twelve sticks (0.65 ± 0.05 mm2 of area) from the central area of each tooth were fractured in tension (0.5 mm/min). Sticks from each group were processed for interfacial micromorphological evaluation with SEM., Results: Three-way ANOVA revealed a significant interaction between factors (p < 0.05). Tukey's post-hoc test showed that only when Adper Easy Bond was applied on dentin prepared with 600-grit SiC paper, microtensile bond strength was not significantly affected by the number of coatings. However, the effect of smear layer thickness was only statistically significant when the adhesives were applied in one coat, for both adhesives. When they were applied in two or three coats, smear layer thickness did not significantly affect bond strength (p > 0.05)., Conclusions: The thickness of the smear layer affected the bond strength of both all-in-one adhesives. Additional coats can be beneficial to bond strength, especially with Clearfil S3 Bond.

Purpose: To evaluate whether the use of a desensitizing agent before at-home vital bleaching decreased this sensitivity., Methods: After informed consent, 60 subjects, 18-31 years of age, participated in the study and were divided into desensitizer and placebo groups. Before bleaching treatment with 16% carbamide peroxide (CP), a placebo or desensitizer gel (DG; 5% potassium nitrate and 2% sodium fluoride) was applied in the tray and used by patients for 10 minutes. Color was evaluated at the baseline, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. The subjects recorded their perception of tooth sensitivity on a 0-4 scale. The bleaching treatment at each week recall was evaluated by repeated measures ANOVA. The percentage of patients with tooth sensitivity was evaluated by Chi-square test. The tooth intensity ratio (% of days with tooth sensitivity) as well as the tooth sensitivity intensity between groups were analyzed using chi-square and the Mann-Whitney tests, respectively (alpha = 0.05)., Results: The use of DG did not affect the bleaching efficacy of the CP (P > 0.05). The prevalence and intensity of tooth sensitivity was similar for both groups (P > 0.05). However, participants from the placebo group had sensitivity in 33.6% of the bleaching days, which was significantly higher than the DG experimental group (20.1%) (P < 0.05).

The aim of this in vitro study was to evaluate the microtensile bond strength (µTBS) of a low-shrink silorane-based composite (Filtek Silorane) and a methacrylate-based composite (Filtek Z250) to the bottom dentin of a Class I cavity using different placement techniques. Twelve third molars were used. Standard, box-type Class I cavities (6.0 x 4.0 x 2.5 mm) were prepared at the occlusal crown center, with the pulpal floor ending approximately at the midcoronal dentin. The teeth were then randomly divided into four groups, according to each placement technique: ZI--Filtek Z250 placed incrementally; ZB--Filtek Z250 placed in bulk; SI--Filtek Silorane placed incrementally; and SB--Filtek Silorane placed in bulk. Each restored third molar was subjected to microtensile bond testing after 24 hours of storage in distilled water at 37 degrees C. After storage, each molar was longitudinally sectioned in both axes to obtain rectangular sticks with an approximate 0.49 mm2 cross-sectional area. Data were analyzed by one-way ANOVA followed by a Tukey post hoc test (P = 0.05). After debonding, the failure modes were analyzed using a stereomicroscope. The ZI group (72.6 MPa) showed the highest µTBS, followed by the ZB group (60.2 MPa), while the SI (34.4 MPa) and SB (42.6 MPa) groups demonstrated statistically significant lower bond strengths. The type of placement technique did not influence the µTBS of silorane-based composites to the bottom dentin of Class I cavities. The methacrylate-based composite showed superior performance, regardless of the placement technique.

Dental erosion is a contemporary disease, mostly because of the change of the eating patterns that currently exist in society. It is a "silent" and multifactorial disease, and is highly influenced by habits and lifestyles. The prevalence of dental erosion has considerably increased, with this condition currently standing as a great challenge for the clinician, regarding the diagnosis, identification of the etiological factors, prevention, and execution of an adequate treatment. This article presents a dental erosion review and a case report of a restorative treatment of dental erosion lesions using a combination of bonded ceramic overlays to reestablish vertical dimension and composite resin to restore the worn palatal and incisal surfaces of the anterior upper teeth. Adequate function and esthetics can be achieved with this approach., (© 2011 Wiley Periodicals, Inc.)

Objectives: To evaluate the toothbrush wear resistance of infiltrated artificial white spot lesions following two infiltration strategies, and to assess their ultramorphology., Methods: Flat enamel surfaces from freshly extracted bovine teeth were polished and immersed in a Buskes demineralising solution for 30 days to create incipient caries-like lesions (white spots). Two experimental regions on the surface of each tooth were infiltrated with an infiltrant and a commercial etch-and-rinse adhesive. Toothbrush abrasion was applied for 20,000 cycles. Vertical wear loss of the infiltrated areas was measured after 10,000 and 20,000 cycles against unabraded and abraded enamel using confocal laser scanning microscopy (CLSM; multiple t-tests, α=0.05). Each lesion's surface and cross-section were evaluated under CLSM and scanning electron microscopy after etching and infiltration to assess ultramorphology., Results: After 20,000 abrasion cycles, a statistically non-significant difference in vertical wear loss was measured for the infiltrant versus the adhesive compared with the original enamel (42.6±20.7 μm vs. 40.4±18.5 μm, p>0.05). Irregular surface profiles were common for the adhesive-infiltrated group as a result of peeling and blistering of the resin-covering layer. Ultramorphology of the infiltrated lesions revealed different patterns of penetration regarding density and depth., Conclusions: Although both infiltration strategies had equivalent wear resistance to toothbrush abrasion, surface and morphological aspects pointed to improved surface stability and infiltration quality for the infiltrant material., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Statement of Problem: Ultra-thin bonded posterior occlusal veneers represent a conservative alternative to traditional inlays and complete coverage crowns for the treatment of severe erosive lesions. There is a lack of data regarding selection of the most appropriate material and its influence on fatigue resistance, which may affect restoration longevity., Purpose: The purpose of this study was to assess the influence of CAD/CAM restorative material (ceramic vs. composite resin) on fatigue resistance of ultra-thin occlusal veneers., Material and Methods: A standardized nonretentive tooth preparation (simulating advanced occlusal erosion) was applied to 40 extracted molars including removal of occlusal enamel, and immediate dentin sealing (Optibond FL). All teeth were restored with a 0.6 mm-thick occlusal veneer (Cerec3 chairside CAD/CAM system). Reinforced ceramics (Empress CAD and e.max CAD) and composite resins (Paradigm MZ100 and XR (experimental blocks)) were used to mill the restorations (n=10). The intaglio surfaces were HF-etched and silanated (reinforced ceramics) or airborne-particle abraded and silanated (composite resins). Preparations were airborne-particle abraded and etched before restoration insertion. All restorations were adhesively luted with preheated Filtek Z100. Cyclic isometric loading was applied at 5 Hz, beginning with a load of 200N (x5,000), followed by stages of 400, 600, 800, 1000, 1200 and 1,400N at a maximum of 30,000 cycles each. The number of cycles at initial failure (first cracks) was recorded. Specimens were loaded until catastrophic failure (lost restoration fragment) or to a maximum of 185,000 cycles. Groups were compared using the life table survival analysis (α=.008, Bonferroni-method)., Results: Empress CAD and e.max CAD initially failed at an average load of 500N and 800N, respectively with no specimen withstanding all 185,000 load cycles (survival 0%); with MZ100 and XR the survival rate was 60% and 100%, respectively., Conclusions: Both composite resins (MZ100 and XR) increased the fatigue resistance of ultra-thin occlusal veneers (P<.001) when compared to the ceramics evaluated (Empress CAD and e.max CAD)., (Copyright © 2011 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.)

Objectives: The aim of this study was to evaluate the fatigue limits of the dentin-composite interfaces established either with an etch-and-rinse or an one-step self-etch adhesive systems under tensile and bending configurations., Methods: Flat specimens (1.2 mm×5 mm×35 mm) were prepared using a plexiglass mold where dentin sections from human third molars were bonded to a resin composite, exhibiting the interface centrally located. Syntac Classic and G-Bond were used as adhesives and applied according to the manufacturer's instructions. The fluorochrome Rhodamine B was added to the adhesives to allow for fractographic evaluation. Tensile strength was measured in an universal testing machine and the bending strength (n=15) in a Flex machine (Flex, University of Antwerp, Belgium), respectively. Tensile (TFL) and bending fatigue limits (BFL) (n=25) were determined under wet conditions for 10(4) cycles following a staircase approach. Interface morphology and fracture mechanisms were observed using light, confocal laser scanning and scanning electron microscopy. Statistical analysis was performed using three-way ANOVA (mod LSD test, p<0.05)., Results: Tensile and bending characteristic strengths at 63.2% failure probability for Syntac were 23.8 MPa and 71.5 MPa, and 24.7 MPa and 72.3 MPa for G-Bond, respectively. Regarding the applied methods, no significant differences were detected between adhesives. However, fatigue limits for G-Bond (TFL=5.9 MPa; BFL=36.2 MPa) were significantly reduced when compared to Syntac (TFL=12.6 MPa; BFL=49.7 MPa). Fracture modes of Syntac were generally of adhesive nature, between the adhesive resin and dentin, while G-Bond showed fracture planes involving the adhesive-dentin interface and the adhesive resin., Significance: Cyclic loading under tensile and bending configurations led to a significant strength degradation, with a more pronounced fatigue limit decrease for G-Bond. The greater decrease in fracture strength was observed in the tensile configuration., (Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Objectives: To evaluate the dentin bond durability of simplified adhesives after one-year (1 y) under water storage and simulated pulpal pressure., Methods: Class I cavities were prepared in sixty human third molars with the pulpal wall located in mid-coronal dentin. The roots were cut off to expose the pulpal chamber, and the teeth were assembled in a pulpal pressure simulator device. A two-step etch-and-rinse adhesive (Single Bond 2/SB), a two-step self-etch adhesive (Clearfil SE Bond/CSE), a three-step self-etch adhesive (Adper Scotchbond SE/SSE) and three all-in-one adhesives (Adper Easy Bond/EB, Clearfil S(3) Bond/S3 and Adhese One/AO) were applied according to manufacturers instructions. No enamel pre-etching was used for the self-etch systems. The cavities were filled with a composite (Z250, 3M ESPE) in four to five horizontal increments and individually cured. Immediately after the final cure, pulpal pressure was set to 15 cm H(2)O. After 24 h and 1 y under simulate pulpal pressure the teeth were cut following a 'nontrimming' microtensile test technique (n=30) and tested in tension. Kruskall-Wallis and post hoc multiple comparisons were used at alpha=0.05. Weibull statistics was applied to SB, CSE and EB. Fractographic analysis of debonded specimens was performed using scanning electron microscopy., Results: At 24 h and 1 y periods, SB showed higher bond strength means than all the others adhesives tested. CSE was not statistically different from EB at 24 h and from EB and SB at 1 y. EB showed bond strength statistically higher than the other three self-etch adhesives, which were not statistically different from each other at 24 h. AO showed significantly lower bond strength than all tested materials after 1 y. For all adhesives the mean bond strength at 1 y were not statistically different from the values measured at 24 h (p>0.05). Shifts in failure mode patterns and Weibull modulus decrease indicate some degree of bond degradation after the 1 y storage period., Conclusion: One-year of simulated pulpal pressure did not affect dentin bond strength of simplified adhesives in Class I restorations. Signs of degradation were only revealed by fractographic analysis and reliability parameters., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Background: The daily application time for 10 percent carbamide peroxide (CP) typically is between four and eight hours. However, to the authors' knowledge, no investigators in clinical studies have compared different application times; this is the aim of this study., Methods: The authors recruited 60 patients and categorized each of them into one of four groups. All participants used 10 percent CP in a bleaching tray. The daily application times were 15 minutes, 30 minutes, one hour or eight hours. Participants bleached their teeth for 16 days and those who were not satisfied with the results extended the bleaching time until they were satisfied. Patients recorded their tooth sensitivity on a 0 to 4 scale. The authors measured the shade changes by using a digital spectrophotometer and shade guide. They performed appropriate statistical analysis of the data (α = .05)., Results: Participants in the one- and eight-hour groups bleached their teeth for 18 and 16 days, respectively (P > .05), while statistically longer periods were required for participants in the other two groups (P < .001) to be satisfied with the results. Participants' tooth sensitivity ratings were similar for the 15-minute, 30-minute and one-hour application times (P > .05), and they were statistically lower than those for participants in the eight-hour group., Conclusions: The eight-hour bleaching protocol yielded faster bleaching; however, participants experienced higher sensitivity levels. The one-hour group most closely approached the eight-hour group with regard to bleaching speed, while those in the one-hour group experienced lower sensitivity levels., Clinical Implications: In this study, the difference in bleaching speed between the eight- and one-hour application times after 16 days was small, and the results showed less tooth sensitivity for patients in the one-hour group.

Statement of Problem: Thin, bonded, posterior occlusal veneers constitute a conservative alternative to traditional complete coverage crowns. Information regarding selection of the appropriate material and its influence on fatigue resistance, which may affect the longevity of the restoration, is missing., Purpose: The purpose of this study was to assess and compare the fatigue resistance of composite resin and ceramic posterior occlusal veneers., Material and Methods: Thirty extracted molars received a standardized nonretentive tooth preparation (simulating advanced occlusal erosion), including removal of occlusal enamel, exposure of dentin, and immediate dentin sealing (Optibond FL). All teeth were restored with a 1.2-mm-thick occlusal veneer (Cerec 3 chairside CAD/CAM system). The restorations (n=10) were milled from leucite-reinforced and lithium disilicate ceramics (IPS Empress CAD and IPS e.max CAD, respectively) and a composite resin (Paradigm MZ100). The intaglio surfaces of the ceramic restorations were conditioned by hydrofluoric acid etching and silane. Airborne-particle abrasion and silane were used to condition the composite resin restorations. Preparations were airborne-particle abraded and etched. All restorations were bonded with preheated luting material and submitted to cyclic isometric loading at 5 Hz, starting with a load of 200 N (x5000 cycles), followed by stepwise loading of 400, 600, 800, 1000, 1200, and 1400 N at a maximum of 30,000 cycles each. The number of cycles at initial failure (first cracks) was recorded. Specimens were loaded for a maximum of 185,000 cycles. Groups were compared using the life table survival analysis (alpha=.016, Bonferroni method)., Results: IPS Empress CAD failed at an average load of 900 N, with no specimen withstanding all 185,000 load cycles (survival 0%), while IPS e.max CAD and Paradigm MZ100 demonstrated survival rates of 30% and 100%, respectively. None of the specimens exhibited catastrophic failure, but only cracks limited to the restorative material., Conclusions: Posterior occlusal veneers made of composite resin (Paradigm MZ100) had significantly higher fatigue resistance (P<.002) compared to IPS Empress CAD and IPS e.max CAD., (Copyright © 2010 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.)