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Purpose: To measure zirconia-to-zirconia microtensile bond strength (µTBS) using composite cements with and without primer. Materials and Methods: Two Initial Zirconia UHT (GC) sticks (1.8x1.8x5.0 mm) were bonded using four cements with and without their respective manufacturer's primer/adhesive (G-CEM ONE [GOne] and G-Multi Primer, GC; Panavia V5 [Pv5]), and Panavia SA Cement Universal [PSAu], and Clearfil Ceramic Plus, Kuraray Noritake; RelyX Universal (RXu) and Scotchbond Universal Plus [SBUp], 3M Oral Care). Specimens were trimmed to an hour-glass shaped specimen whose isthmus is circular in cross-section. After 1-week water storage, the specimens were either tested immediately (1-week µTBS) or first subjected to 50,000 thermocycles (50kTC-aged µTBS). The fracture mode was categorized as either adhesive interfacial failure, cohesive failure in composite cement, or mixed failure, followed by SEM fracture analysis of selected specimens. Data were analyzed using linear mixed-effects statistics (α = 0.05; variables: composite cement, primer/adhesive application, aging). Results: The statistical analysis revealed no significant differences with aging (p = 0.3662). No significant difference in µTBS with/without primer and aging was recorded for GOne and PSAu. A significantly higher µTBS was recorded for Pv5 and RXu when applied with their respective primer/adhesive. Comparing the four composite cements when they were applied in the manner that resulted in their best performance, a significant difference in 50kTC-aged µTBS was found for PSAu compared to Pv5 and RXu. A significant decrease in µTBS upon 50kTC aging was only recorded for RXu in combination with SBUp. Conclusion: Adequate bonding to zirconia requires the functional monomer 10-MDP either contained in the composite cement, in which case a separate 10-MDP primer is no longer needed, or in the separately applied primer/adhesive. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the color match and stability of single-shade resin-based composites (RBCs) in Class V restorations before and after ultra-violet light artificial aging. Methods: Acrylic resin teeth of A1 and A3 were randomly assigned into seven groups to be restored with single-shade RBCs and universal-shade RBCs, shades A1 and A3. Standardized Class V cavities were restored using RBC and underwent accelerated aging for 480 hours. The color differences between RBC and Class V restorations for A1 and A3 were evaluated before and after artificial aging using a spectrophotometer. Results: All single-shade RBCs better color-matched the A1 tooth (P= 0.10 to P= 0.32), while universal-shade RBCs color better matched the A3 tooth (P= 0.03 to P= 0.87). Omnichroma was the only single-shade RBC that also color-matched the A3 tooth (P= 0.03). There was a statistically significant difference when comparing measurements before and after the aging only for Vittra APS Unique (P= 0.047) and Omnichroma (P= 0.038) and the A3 tooth. [ABSTRACT FROM AUTHOR]

The use of dental ceramics on anterior teeth is associated with predictable and long-lasting esthetic results. However, treatment on darkened substrates is challenging. Various conservative options, including ceramic veneers, are available to change the shape and color of anterior teeth. The aim of this case report is to describe the esthetic rehabilitation of a darkened central incisor in a maxillary anterior region that had irregular gingival contours, multiple composite resin restorations, and unsatisfactory tooth shapes. Harmony was restored through periodontal recontouring surgery, placement of a lithium disilicate crown (consisting of a veneer cemented to a coping) on the darkened central incisor, and placement of lithium disilicate veneers on the other maxillary anterior teeth. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In spite of advances in materials and techniques for direct posterior composite restorations, some problems remain, such as occlusal wear rate, marginal breakdown, and marked operator technique sensitivity. To enhance longevity of these restorations, finishing and polishing procedures are commonly indicated. Although these procedures offer advantages, they also have some drawbacks, such as higher marginal breakdown and increased susceptibility to wear following finishing procedures. Faced with the disadvantages brought by finishing and polishing procedures, it seems reasonable to try and find a technique to omit them. This paper presents clinical cases exhibiting a restorative technique that prevents, or at least reduces, the need for instrumentation of the restoration. In cases when finishing procedures are necessary, the restorations should be sealed with a specific resinous agent to impart new strength to the instrumented surface and improve marginal integrity. In addition, the suggested technique promotes a better occlusal anatomy than that attained with the traditional technique. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the morphology of the resin-dentin interface formed in vivo with two posterior resin composite placement techniques (incremental and bulk). Method and materials: After approval from the patients, 12 Class II cavities with margins in enamel (2.5 x 2.5 x 4.5 mm) were prepared in caries-free premolars scheduled to be extracted for orthodontic reasons (n = 6). The cavities were restored with Single Bond + Filtek P60 as a bulk condensable technique or Single Bond + Filtek Z250 as an oblique incremental technique. After 1 week, the teeth were extracted with minimal trauma to the restored area. After the teeth were sectioned, a polyvinyl siloxane impression was taken from the resin-dentin interface to control for artifacts created during preparation for scanning electron microscopy. The specimens were subsequently processed for and observed under a scanning electron microscope to assess gap formation. Results: The mean percentage of gap formation was 6.1% for teeth restored with the incremental placement technique and 18.7% for teeth restored with the bulk placement technique. The difference was statistically significant. Conclusion: The incremental placement of posterior resin composites may still provide better seal than the new bulk condensable technique. [ABSTRACT FROM AUTHOR]

Enamel adhesion by means of acid etching has become an accepted technique in restorative dentistry. Adhesion to dentin, however, is still under investigation. At this time, two distinct adhesive techniques are prominent in the attempt to establish a strong bond to dentin: total-etch and self-etching primers. Total-etch bonding systems have been shown to be effective both in vitro and in clinical evaluations. The new total-etch one-bottle bonding systems, although exhibiting the same success on laboratory tests, still have to prove their clinical effectiveness. Self-etching primer systems are undergoing rapid evolution; their results are not yet sufficiently predictable overall, but some systems have achieved positive results in both enamel and dentin bonding. Further studies are necessary to confirm the long-term efficiency of these self-etching primers. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Enamel defects, such as white or yellow-brown spots, usually cause problems that are more esthetic than functional. Enamel hypoplasia may be the result of hereditary, systemic, or local factors. Dental trauma is a local etiologic factor. It is relatively common in the primary dentition and can cause defects on the surface of permanent successors. Treatment for such defects can differ, depending on the depth of the spots. For deeper white-spot lesions, a composite resin restoration may be necessary. This is an excellent mode of treatment, due to both its low cost and its conservation of healthy tooth structure. The objective of this case report is to describe composite resin restoration of a maxillary central incisor affected by enamel hypoplasia. [ABSTRACT FROM AUTHOR]

This paper aimed to review the current literature on the clinical effectiveness of two isolation methods (rubber dam vs cotton rolls) when used to restore Class V noncarious cervical lesions and to present one case report with the cotton roll technique. Literature published from October 1987 to April 2007 was reviewed. Thirteen clinical trials that tested the effectiveness of both isolation methods in Class V noncarious cervical lesions were identified. The guidelines of the American Dental Association for dentin and enamel adhesive materials were used as a reference. Only three clinical trials were found in the literature that compared both isolation approaches; however, these studies used older adhesive systems. Future studies using more contemporary adhesive systems should be conducted to evaluate the influence of the isolation method on the performance of Class V restorations. [ABSTRACT FROM AUTHOR]

The interest of patients in having tooth-colored restorations and the development of techniques and materials that make these restorations easier have contributed to make the esthetic restoration of posterior teeth popular. The direct use of composites in posterior teeth is a technique-sensitive procedure. Some difficulties, nevertheless, can be overcome or at least minimized by a heedful clinician by paying thorough attention to the various stages of the restorative technique. The present article seeks to review some concepts about this adhesive restorative procedure and to illustrate the possibilities of the technique with clinical reports. CLINICAL SIGNIFICANCE The direct posterior composite restorative technique offers the possibility of closely matching the natural optical characteristics of the lost tooth structure. Aimed at showing the potential of this technique, this article presents two step-by-step case reports and also reviews some concepts related to these clinical procedures. [ABSTRACT FROM AUTHOR]