A practical, predictable, and reliable method to select shades for direct resin composite restorations.

OBJECTIVE: This article describes a practical, predictable, and reliable method to select shades for direct composite restorations using custom shade guides made of resin composite at hand using a process of elimination CLINICAL CONSIDERATIONS: Esthetics in direct resin composite restorations depends on the clinician's ability to reproduce the shape and shade of natural teeth, thus appropriate shade selection is a must. This method presented in this article simplifies the process of shade selection for direct resin composite restorations. The use of custom shades tabs made of commecially available resin composites, its arrangment and a process of elimination of tabs during shade selection allows the practitioner to obtain the best possible resin composite shade available for every case. CONCLUSIONS: The use of custom shade guide tabs and an elimination protocol facilitates and expedites the process of shade selection for direct resin composites CLINICAL SIGNIFICANCE: The article presents a practical, predictable, and reliable method to select shades for direct resin composite restorations for daily practice.

A systematic approach to contouring and polishing anterior resin composite restorations: A checklist manifesto.

PURPOSE: This article presents a systematic, step-by-step checklist approach to be used for contouring and polishing anterior resin composite restorations to achieve maximum esthetics efficiently. CLINICAL CONSIDERATIONS: This checklist is intended to be used to take the guesswork out and streamline the process to predictably, practically, and repeatedly contour and polish anterior resin composite restorations. The practitioner's knowledge of basic dental anatomy combined with this step-by-step checklist facilitates identifying and modifying the final restoration to an anatomically correct form, thus satisfying the most esthetically demanding patients. This approach is demonstrated with case presentation of direct resin veneers in a young female, which resulted in an improved smile that satisfied her esthetic desires. CONCLUSIONS: The use of standardized protocols facilitates and expedites daily procedures in dentistry. Specifically, this checklist protocol, which is geared towards contouring and polishing anterior direct resin composite restorations. CLINICAL SIGNIFICANCE: The clinical technique presented in this article shows the advantages of using a step-by-step checklist approach to predictably and efficiently obtain ideal esthetics when performing anterior resin composite restorations.

Microtensile bond strength to dentin and enamel of self-etch vs. etch-and-rinse modes of universal adhesives.

PURPOSE: To compare the immediate microtensile bond strengths (µTBSs) of four mild self-etch universal adhesives applied to dentin and enamel with self-etch and etch-and-rinse techniques. METHODS: Flat middle dentin surfaces from 104 human teeth and two enamel fragments from another 104 human teeth were randomly distributed into eight groups according to the various adhesive systems used: Scotchbond Universal (SBU) [etch-and-rinse mode vs. self-etch mode]; Optibond XTR (OPT) [ etch-and-rinse mode vs. self-etch mode]; Clearfil Universal Bond Quick (CL) [ etch-and-rinse mode vs. self-etch mode]; and Adhese Universal (ADH) [etch-and-rinse mode vs. self-etch mode]. After 24 hours of water storage, the bonded sticks were tested for µTBS. The differences in the pre-test failure and fracture-failure modes were tested by a two-way ANOVA and GEE model analysis. Bond-strength data were analyzed with a two-way ANOVA and mixed-model analysis. RESULTS: : For dentin, the mean µTBS was statistically different among the four adhesives, but not different between the self-etch and etch-and-rinse modes. For enamel, the mean µTBS was statistically different among the four adhesives, as was the application mode. GEE model analysis revealed a statistically significant adhesive failure rate proportion among the four types of adhesives for both enamel and dentin. CLINICAL SIGNIFICANCE: Etching enamel prior to the application of a universal adhesive can be recommended as an approach to enhance bond strength.

Ceramic materials for porcelain veneers: part II. Effect of material, shade, and thickness on translucency.

STATEMENT OF PROBLEM: Information regarding the differences in translucency among new ceramic systems is lacking. PURPOSE: The purpose of this study was to compare the relative translucency of the different types of ceramic systems indicated for porcelain veneers and to evaluate the effect of shade and thickness on translucency. MATERIAL AND METHODS: Disk specimens 13 mm in diameter and 0.7-mm thick were fabricated for the following 9 materials (n=5): VITA VM9, IPS Empress Esthetic, VITA PM9, Vitablocks Mark II, Kavo Everest G-Blank, IPS Empress CAD, IPS e.max CAD, IPS e.maxPress, and Lava Zirconia. VITA VM9 served as the positive control and Lava as the negative control. The disks were fabricated with the shade that corresponds to A1. For IPS e.maxPress, additional disks were made with different shades (BL2, BL4, A1, B1, O1, O2, V1, V2, V3), thickness (0.3 mm), and translucencies (high translucency, low translucency). Color coordinates (CIE L∗ a∗ b∗) were measured with a tristimulus colorimeter. The translucency parameter was calculated from the color difference of the material on a black versus a white background. One-way ANOVA, the post hoc Tukey honestly significant difference, and the Ryan-Einot-Gabriel-Welsch multiple range tests were used to analyze the data (α=.05). RESULTS: Statistically significant differences in the translucency parameter were found among porcelains (P<.001) according to the following rank: VM9>PM9, Empress Esthetic>Empress CAD>Mark II, Everest, e.max CAD>e.max Press>Lava. Significant differences also were noted when different shades and thickness were compared (P<.001). CONCLUSIONS: Different ceramic systems designed for porcelain veneers present varying degrees of translucency. The thickness and shade of lithium disilicate ceramic affect its translucency. Shade affects translucency parameter less than thickness.

Ultrathin Feldspathic Ceramic Veneers: A Pilot SEM Evaluation of Etched Intaglio Surfaces.

Ultrathin ceramic veneers are a viable therapeutic option to manage esthetic challenges in the anterior zone. Proper conditioning of the intaglio surface of porcelain veneers is essential to achieve an adequate bonding. In clinical practice, this is typically done with chemical etching using an acid-containing agent, such as hydrofluoric acid. While it is well established that the etching effect is dependent on etching time and the acid concentration, little is known about the impact of etching time and the veneer fabrication method. The purpose of this pilot study was to evaluate, using scanning electron microscopy (SEM), the effect that different etching-time protocols have on the intaglio surface characteristics of ultrathin ceramic veneers fabricated with either the platinum foil technique or the refractory die technique. Several replicas of an ultrathin feldspathic ceramic veneer for a maxillary central incisor were fabricated. Individual specimens were processed according to different intaglio surface-etching protocols: no etching, etching for 90 seconds, etching for 120 seconds, and etching for 150 seconds (9.6% hydrofluoric acid used for all etching groups). It was observed that the 120-second etching protocol resulted in a favorable microroughness surface pattern in the platinum foil group. This pattern was comparable to that obtained by etching for 90 seconds with hydrofluoric acid the intaglio surface of veneers fabricated with the refractory die technique. Increasing the etching time to 150 seconds did not result in a more favorable roughness pattern.

A Comparative Study of Shade-Matching Reproducibility Using an Intraoral Scanner and a Spectrophotometer.

BACKGROUND: We compared the repeatability of the shade determination of resin composite restorations and acrylic teeth in light and darker shades at baseline and after an aging process through two digital tooth color-matching methods: using a Trios 3Shape intraoral scanner and using a Vita Easyshade Compact spectrophotometer. MATERIAL AND METHODS: Forty upper central incisor acrylic teeth in the shade A1 (n = 10) and A3 (n = 10) were randomly assigned to be restored with Filtek Bulk Fill in the shade A1 (n = 10) or A3 (n = 10). Subsequently, 20 Class V cavities were prepared in a standardized manner (mesio-distal = 3.0 mm, cervical-occlusal = 2.0 mm, depth = 1.5 mm). Cavities were restored using an universal adhesive system and resin composite in two increments and were light-cured. The shade difference between the resin composite Class V restorations in acrylic teeth of the A1 and A3 shades was evaluated at baseline and after aging. Aging was simulated using ultraviolet light for 120 h. An Easyshade device and an intraoral scanner were used under D65 illumination. Measurements were taken five times, on top of the restoration and on the acrylic teeth, in a randomized manner. RESULTS: Data analysis was on the calculation of the arithmetic mean for the percentage of repeatability conducted by the Trios scanner and the Easyshade device. There was no statistically significant comparison between the shade measurement devices (p > 0.05). At baseline, the repeatability for both the Trios intraoral scanner and the Vita Easyshade Compact device for artificial teeth in the shades A1 and A3 was 100%. After aging, the trueness recorded by the intraoral scanner and the Easyshade device for artificial teeth in the shade A1 was 80%. For Class V restoration with shade A1, the intraoral scanner recorded 80% trueness and the Easyshade device recorded 60% trueness at baseline. For shade A3, the intraoral scanner recorded 60% trueness and the Easyshade device recorded 60% trueness. CONCLUSIONS: The intraoral scanner and Easyshade device are reliable for baseline shade selection, but their accuracy decreases after aging, particularly for darker shades.

Effect of polishing direction on the marginal adaptation of composite resin restorations.

PROBLEM: Polishing composite resin restorations may lead to marginal defects and gap formation. PURPOSE: To assess the effect of polishing direction on the marginal adaptation of composite resin restorations using two composite resins and two polishing systems. MATERIALS AND METHODS: Forty extracted human molars were sectioned along their mesio-distal axis. Buccal and lingual enamel was flattened and a triangular preparation, 0.87-mm deep and 3-mm wide, representing two 60° bevels, was performed. Specimens were randomly assigned to eight groups (N = 20) and restored with two composite resins: a nanofilled (Filtek Supreme Ultra, 3M ESPE, St. Paul, MN, USA) or a microhybrid (Point 4, Kerr, Orange, CA, USA) and finished with two polishing techniques: polishing discs (Sof-Lex XT, 3M ESPE) or rubber polishers (HiLuster Plus, Kerr, Bioggio, Switzerland). On each specimen, both margins were polished with the same technique, one margin from composite resin to tooth and the other from tooth to composite resin. Replicas were made for field emission scanning electron microscope observation (200×) and quantitative margin analysis was performed based on four criteria. Data were analyzed with a paired-sample t-test, a two-sample t-test, and one-way analysis of variance or their nonparametric analog. RESULTS: Significant differences were found in most groups between polishing directions with better marginal adaptation from composite resin to tooth than from tooth to composite resin. Differences between composite resins and polishing techniques seemed to be dependent on certain combinations of composite resin, polishing technique, and polishing direction. CONCLUSION: Polishing from composite resin to tooth leads to better marginal adaptation than polishing from tooth to composite resin. CLINICAL SIGNIFICANCE: The results obtained from this in vitro study suggest that polishing direction influences the marginal adaptation of composite resins and that polishing from composite resin to tooth structure should be clinically performed whenever possible on accessible margins to preserve marginal integrity and esthetics.

Ceramic materials for porcelain veneers. Part I: Correlation between translucency parameters and contrast ratio.

STATEMENT OF PROBLEM: Different parameters are used in the literature to describe translucency, making it difficult for clinicians to find clear information on ceramic translucency and compare studies. PURPOSE: The purpose of this study was to assess the correlation between the contrast ratio (CR) and translucency parameter (TP) when the translucency of different types of ceramic systems is compared. MATERIAL AND METHODS: Disks 13 mm in diameter and 0.7 mm thick were fabricated for the following materials (n=5): VITA VM9, VITA PM9, IPS Empress CAD, IPS e.max CAD, IPS e.maxPress, and Lava Zirconia. VITA VM9 served as positive control, while Lava Zirconia served as negative control. The luminous reflectance (Y) and color coordinates (CIE L* a* b*) of the specimens were measured with a tristimulus colorimeter. The CR (CR=Yb/Yw) was calculated from the reflectance of the light of the material on a black backing (Yb) to the reflectance on a white backing (Yw). The TP (TP=[(Lb*Lw*)(2+)(ab*-aw*)(2+)(bb*-bw*)(2) ](1/2)) was calculated from the color difference of the material on a black versus a white background. One-way ANOVA based on ranked data and the Pearson and Spearman rank correlation tests were used to analyze the data (α=.05). RESULTS: A significant correlation between CR and TP was found when all specimens were included (P<.001). The coefficient of -0.99 indicated a strong decreasing relationship between the 2 variables. CONCLUSIONS: Either CR or TP can be used to evaluate the relative translucency of ceramic systems.

Fracture resistance of defective amalgam restorations repaired with a resin-based composite material.

BACKGROUND: Repair is used to increase the longevity of defective restorations, such as large amalgams. The aim of this study was to investigate the fracture resistance and fracture modes of mesio-occlusodistal (MOD) amalgam molar restorations with extensive cuspal fracture repaired or replaced using a bulk-fill resin-based composite material. METHODS: Amalgam restorations were placed in 84 permanent extracted molars and randomly assigned (n = 14) to groups: (1) MOD amalgam, (2) composite repair of 1-cusp fracture and adjacent proximal box, (3) composite repair of 1-cusp fracture, (4) composite repair of 2-cusp fracture, (5) replacement of 1-cusp defect and existing MOD amalgam, (6) replacement of 2-cusp defect and MOD amalgam. Each molar was prepared to simulate the assigned fracture and either repaired or replaced. Specimens were aged and then loaded to fracture. Fracture resistance and fracture modes were recorded. RESULTS: The authors found significant differences (P < .001) between group 4 (1,652.3 N) and groups 5 (3,095.0 N), 1 (2,669.8 N), 6 (2,658.6 N), and 2 (2,442.9 N) as well as between group 3 (2,133.5 N) and group 5 (3,095.0 N). The results of the Fisher exact test showed differences among groups (P < .001), with group 5 having the highest number of nonrestorable fractures as well as higher fracture resistance on average. CONCLUSIONS: Composite material is a viable option for the repair and replacement of cuspal defects, especially in the case of a 1-cusp fracture and 1-cusp fracture involving the adjacent proximal box. PRACTICAL IMPLICATIONS: Within the limitations of this study, the repair of cusp fractures in existing MOD amalgam-restored molars is an appropriate treatment option, although replacement of the defect and existing restoration with resin-based composite will withstand higher forces.

Dentin adhesives application deviations: Effects on permeability and nanoleakage.

The purpose was to evaluate the effect that deviations from the recommended protocol of a two-step etch-and-rinse adhesive system has on permeability and nanoleakage. One hundred and twenty dentin disks were treated with a two-step etch-and-rinse adhesive system, according to the manufacturer's instructions, or using five simulated deviations from the recommended protocol: applying potassium oxalate, reducing the application time of the adhesive, avoiding adhesive drying, aggressively drying the adhesive, and double application of adhesive. Kruskal-Wallis and Tukey's post hoc comparisons were used to evaluate the permeability reduction (α=0.05). Twelve additional dentin disks were prepared for transmission electron microscope (TEM) analysis of nanoleakage. Aggressive drying, adding additional layers of adhesive or using oxalate reduced dentin permeability and yielded a better infiltration of the hybrid layer, whereas reducing the application time or less drying the adhesive did not to reduce dentin permeability, caused extensive nanoleakage, showing immediate compromised dentin sealing.

Human perception of dental porcelain translucency correlated to spectrophotometric measurements.

PURPOSE: This study evaluated the relationship between instrumental measurements and subjective visual assessment of differences in dental porcelain translucency. MATERIALS AND METHODS: Unshaded feldspathic porcelain was used with controlled amounts of tin oxide to create two groups of 12-mm diameter disks with incremental changes in opacity. Contrast ratio (CR = Yb/Yw) was determined with a spectrophotometer, and used as a measure of porcelain translucency (Group A = 0.20 to 0.40; Group B = 0.6-0.8). Within each group, there were 14 specimens with 11 CRs. Three observer groups (first year dental students, residents, faculty with >10 years of shade matching experience) were recruited to assess the translucency between porcelain disks under two lighting conditions (reflected light, transmitted light). Each subject's ability to distinguish between specimens of differing translucency was determined. Descriptive statistics and three-way ANOVA followed by a post-hoc Tukey-Kramer test were used to evaluate the translucency perception threshold (TPT) of subjects (alpha= 0.05). RESULTS: The overall mean TPT (DeltaC) was 0.07, while 50% of the subjects could perceive a 0.06 CR difference between porcelain specimens. Three-way ANOVA revealed a significant difference in translucency perception among the observer groups (p < 0.0001), whereas the main effects for porcelain opacity (p= 0.3038) and lighting condition (p= 0.0645) were not significant, and no significant interactions were found. Post-hoc Tukey-Kramer test indicated that the mean TPT observed in the faculty group (DeltaC = 0.04) was significantly lower than those observed in student (DeltaC = 0.09) and resident groups (DeltaC = 0.08), while there was no significant difference between students and residents. CONCLUSIONS: The overall mean TPT of all subjects was 0.07, and 50% of the study population perceived a 0.06 CR difference in translucency. Increased shade matching experience (> or =10 years) significantly improved the ability to perceive differences in translucency; however, neither the viewing condition nor porcelain opacity affected the perceived translucency threshold.

Bio-additive and enameloplasty technique for restoring anterior esthetics: 54-month clinical follow-up.

Teeth with altered size and shape, incisal wear, and inadequate position affect the smile and dentofacial harmony. The aim of this article was to describe a simple and safe protocol for an additive technique with composite resin and cosmetic enameloplasty to improve a patient's smile. A 24-year-old man complained about the appearance of his smile regarding color, shape, and position of the maxillary anterior teeth. Relevant dental history included previous orthodontic treatment with inadequate completion. The clinical examination revealed a disharmony of the smile caused by size and shape alterations of the incisors, a white spot on the right central incisor, incisal wear of the canines, and uneven incisal edges between the maxillary anterior teeth. Treatment with direct composite restoration and enameloplasty was performed in line with the current conservative approach in dentistry. The patient was recalled for 54 months. The use of appropriate techniques in enameloplasty allowed the desired outcome to be observed over the 54 months of follow-up. With this method, it is possible to perform future repair and/or modification, and it may increase the longevity of the restoration. Esthetic and functional results were achieved by careful planning and execution as well as periodic recalls. This conservative approach is a useful alternative to conventional restorations, reducing invasive treatments, chairside time, and costs.

Masking and Penetration Ability of Various Sealants and ICON in Artificial Initial Caries Lesions In Vitro.

PURPOSE: The purpose of the present in vitro study and survey was to compare the masking ability and the penetration capacity of three resin composite sealers as well as a resin infiltrant in shallow artificial caries lesions. MATERIALS AND METHODS: Panels of artificial initial caries lesion with an average depth of 200 µm were created on buccal and lingual surfaces of 75 extracted human molars. Specimens were randomly assigned to 5 groups: ICON (DMG America), Biscover LV (Bisco), Optiguard (Kerr Hawe), Permaseal (Ultradent), and control (no treatment). Teeth were hemi-sectioned yielding two halves, each with a panel of artificial caries lesion. Lesions on one hemi-section were used to assess the esthetic improvement following caries lesion penetration with the 4 resins based on photographs evaluated using a 100-mm visual analogue scale (VAS) by 17 raters. Lesions on opposite hemi-sections were used to measure the resin penetration area percentage (PA%) and the resin penetration depth percentage (PD%) visualized using a confocal laser scanning microscope (CLSM, Leica). RESULTS: ICON, Optiguard, and Permaseal yielded significantly greater average VAS scores compared to Biscover. The mean PA% and PD% were significantly higher for ICON, intermediate for Optibond and Permaseal, and significantly lower for Biscover. A moderately large positive correlation was noticed between the average VAS scores and the penetration measures. CONCLUSION: All the resin sealers (Biscover, Optiguard, and Permaseal) penetrated the artificial initial caries lesions. However, ICON resulted in the deepest penetration and the largest penetration area percentages. The masking ability of Optiguard and Permaseal of the artificial caries lesions was similar to ICON.

Fracture toughness comparison of six resin composites.

OBJECTIVES: This study investigated the Mode I and II fracture toughness values of resin composites used for the restorations of anterior teeth by the Brazilian disk test method. METHODS: The Brazilian disk test was performed on six commercially available dental resin composites, Venus (hybrid resin composite), Durafill (micro-filled resin composite), Gradia (micro-filled/hybrid resin composite), Point4 (hybrid resin composite), Supreme (nano-particle resin composite) and Filtek Z250 (resin composite with zirconia particles). Five resin composite disks of 25 mm in diameter and 2mm in thickness with chevron notches were prepared for each fracture mode per material. The specimens were stored in distilled water for 24h at 37 degrees C, and then tested by a Zwick testing machine under compression mode with a constant crosshead speed of 0.25 mm/min at room temperature. The stress intensity factors under combined Modes I and II fracture toughness were calculated by the formula presented by Atkinson et al. The fracture patterns of two specimens randomly selected from each test group were examined using a scanning electron microscope. A one-way analysis of variance (ANOVA) was performed for the statistical evaluations followed by the post-hoc Tukey's Student Range (HSD) test. RESULTS: The highest mean Mode I and II fracture toughness values were found in Filtek Z250 and Filtek Supreme and they were significantly higher than other materials (comparisons significant at the 0.05 level). The intermediate group consisted of Point4, Venus and Gradia ANTERIOR, whereas Durafill, statistically, had the lowest mean value for fracture toughness. SIGNIFICANCE: Fracture toughness values of hybrid and nano-particle resin composites are significantly higher than those of micro-filled resin composites. This suggests that the latter should be used for non-stress bearing areas.

Effects of oxalate on dentin bond after 3-month simulated pulpal pressure.

OBJECTIVES: Application of an acidic oxalate solution forms calcium oxalate within dentinal tubules and has been used to desensitize dentin and may also improve performance by reducing internal dentin wetness during bonding. The hypothesis tested was that oxalate restriction of dentinal fluid transudation when using an etch-and-rinse two-step adhesive will improve microtensile bond strength (muTBS) and reduce nanoleakage. METHODS: Occlusal dentin of 60 human molars were bonded (Adper Single Bond Plus, 3M ESPE) while one-half of each tooth received either a liquid (SuperSeal, Phoenix Dental) or gel (BisBlock, Bisco) oxalate treatment after acid etching. The restored teeth were placed under pulpal pressure for 3 months before forming cylindrical dumbbell specimens for muTBS and failure pathway determination. Additional teeth were prepared and stored in a similar manner for transmission electron microscopy (TEM) examination of nanoleakage after tracer immersion. RESULTS: The mean bond strength in the group with oxalate liquid and the control group was 27.06+/-7.14 and 36.18+/-9.07 MPa, respectively, and for the gel form of oxalate was 25.34+/-13.09 and 33.09+/-14.25 MPa, respectively. The control groups were significantly stronger than either oxalate group using t-tests (liquid p<0.00001; gel p=0.0032) or Weibull (liquid p=0.0002; gel p=0.0029) statistics. Oxalate groups also demonstrated more adhesive failure modes and nanoleakage. CONCLUSIONS: Under the conditions of this study, the application of oxalate with an etch-and-rinse two-step bonding system produced significantly lower long-term muTBS and enhanced nanoleakage.

Flexural and fatigue strengths of denture base resin.

STATEMENT OF PROBLEM: Mechanical properties of denture acrylic resins are important for the clinical success of multiple types of prostheses. Acrylic resins must be strong and resilient so as to withstand impact. Few studies utilize cyclic loads to characterize material response to repeated stress. PURPOSE: The purpose of this study was to evaluate static and dynamic flexure properties of a variety of acrylic resins utilized in the fabrication of prostheses: (1) heat-polymerized polymethyl methacrylate (PMMA), powder-liquid type, and (2) a newly introduced, visible light-polymerized urethane dimethacrylate dough type. MATERIAL AND METHODS: Twenty rectangular bars each of 4 PMMA acrylic resin materials (Diamond D, Fricke HI-I, Lucitone 199, Nature-Cryl Hi-Plus) and 1 urethane dimethacrylate (Eclipse) were fabricated and stored in 100% humidity for 30 days. Half of the specimens for each group were submitted to a static 3-point flexure test. The other half was submitted to cycling loading at 5 Hz for 10(4) cycles. Data were analyzed using 1-way ANOVA and 2-way ANOVA, followed by Tukey HSD or Bonferroni post hoc tests when necessary (alpha=.05). RESULTS: Mean static flexure strength (SDs) in MPa were: Eclipse, 127.11 (5.83); Diamond D, 84.92 (5.10); Lucitone 199, 83.96 (11.96); HI-I, 79.54 (5.84); and Nature-Cryl Hi-Plus, 75.82 (6.96). Mean flexural strengths (SDs) in MPa postcycling were: Eclipse, 113.36 (31.29); Diamond D, 88.26 (5.46); Nature-Cryl Hi-Plus, 81.86 (4.93); HI-I, 79.18 (6.60); and Lucitone 199, 74.34 (4.95). CONCLUSIONS: The visible light-polymerized urethane dimethacrylate resin (Eclipse) showed greater flexure strength than all PMMA heat-polymerized resins for both static and cycled groups (P<.001). Yet the Eclipse material had lower load limits, and demonstrated brittle-type behavior and greater standard deviations. The heat-polymerized PMMA materials did not significantly differ from each other after static or cyclic testing.

State of the Art of Dental Adhesive Systems.

BACKGROUND: The large dependence on a dental substrate type to bond strength has leveraged the research on materials and techniques that perform different clinical behavior, promoting a stable bonding over time. Bonding to tooth structure has different clinical behaviors and is dependent on several factors. OBJECTIVE: The aim of this paper is to reflect on the state of the art of adhesive systems after the emergence of Buonocore's experiments in current days. METHODS: An electronic search was conducted on PubMed databases and supplemented with a manual study of relevant references. RESULTS: The choice of the ideal adhesive system remains under discussion, housing a range of studies that highlight its potential characteristics, suggesting techniques that enable improvement to boost clinical outcomes. CONCLUSION: It is important to know all different types of adhesive systems, as well as their indications and limitations. An attentive consideration of several factors is crucial to achieve clinical success on the restorative procedures.

Performance of 5 different displays in the detection of artificial incipient and recurrent caries-like lesions.

OBJECTIVES: The aim of this study was to assess whether auto-calibrating medical-grade monitors perform better than off-the-shelf monitors and tablet computers in detecting artificial incipient and recurrent caries-like lesions. STUDY DESIGN: Sixty extracted teeth (30 premolars and 30 molars) were selected. All molars received class II amalgam and composite restorations. A 7-mm2 area on the crowns of half of the teeth was demineralized. Phantoms consisting of 4 teeth were created. Three observers using a 5-point scale evaluated digital periapical radiographs for the presence of caries on 5 displays: 2 autocalibrating medical-grade monitors, 2 tablets, and 1 off-the-shelf monitor. Sensitivity, specificity, accuracy, and receiver operating curve data were calculated and verified through analysis of variance and Tukey tests. Observer agreements were assessed using Cohen's κ test. RESULTS: Intraobserver agreement ranged from 0.347 to 0.612 (molars) and 0.617 to 0.811 (premolars). Interobserver agreement ranged from 0.239 to 0.559 (molars) and 0.657 to 0.858 (premolars). The performances of tablets and the off-the-shelf monitor were similar to medical monitors when the same tooth groups were compared. Medical-grade monitors presented fewer statistically significant differences when different lesions where compared within the same display and restorative material. CONCLUSIONS: Evaluations of similar lesions were not significantly different among the 3 types of displays. However, the autocalibrating medical-grade monitors performed better when incipient and recurrent lesions were compared.

Microleakage of porcelain veneer restorations bonded to enamel and dentin with a new self-adhesive resin-based dental cement.

UNLABELLED: Cementation technique of bonded ceramic restorations is a time-consuming and technique-sensitive procedure critical to long-term success. OBJECTIVE: Evaluate the performance of a self-adhesive, modified-resin dental cement (Rely-X UniCem, 3M-ESPE) for the cementation of ceramic veneer restorations without previous conditioning of the tooth surface, and in combination with a one-bottle adhesive and a self-etching adhesive. METHODS: Thirty-six premolars received a veneer preparation that extended into dentin. Leucite-reinforced pressed glass ceramic (Empress 1) veneers were cemented following manufacturers' instructions, according to the following treatment groups (n=9): (1) Variolink-Excite Ivoclar-Vivadent (V+E control), (2) Unicem+Single Bond 3M-ESPE (U+SB), (3) Unicem+Adper Prompt L-Pop 3M-ESPE (U+AP), (4) Unicem 3M-ESPE (U). After 24h storage at 37 degrees C, teeth were thermocycled (2000 cycles) at 5 and 55 degrees C, immersed in ammoniacal silver nitrate for 24h, placed in a developer solution overnight and sectioned using a slow-speed saw. Three 1mm longitudinal sections were obtained from each tooth and evaluated for leakage with a microscope (1x to 4x). Imaging software was used to measure stain penetration along the dentin and enamel surfaces. RESULTS: ANOVA with SNK (alpha=0.05) revealed that on dentin, U had significantly less leakage than U+SB and U+AP, but no different than V+E; on enamel U had leakage values that were significantly greater than the groups with adhesives. SIGNIFICANCE: The self-adhesive cement U gave low leakage on dentin that was comparable to the cement that employed an adhesive for sealing dentin, whereas this cement benefits from use of an adhesive when cementing to enamel.