ABSTRACT
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.
Subject(s)
Checklist , Dental Polishing , Composite Resins , Dental Restoration, Permanent , Esthetics, Dental , Female , Humans , PolandABSTRACT
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.
Subject(s)
Ceramics/chemistry , Dental Materials/chemistry , Dental Porcelain/chemistry , Dental Veneers , Aluminum Silicates/chemistry , Color , Colorimetry/instrumentation , Humans , Light , Materials Testing , Potassium Compounds/chemistry , Prosthesis Coloring , Surface PropertiesABSTRACT
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.
Subject(s)
Composite Resins/chemistry , Dental Marginal Adaptation , Dental Materials/chemistry , Dental Polishing/methods , Dental Restoration, Permanent , HumansABSTRACT
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.
Subject(s)
Ceramics/chemistry , Dental Porcelain/chemistry , Dental Veneers , Aluminum Silicates/chemistry , Color , Colorimetry/instrumentation , Computer-Aided Design , Dental Materials/chemistry , Dental Polishing/methods , Humans , Light , Materials Testing , Potassium Compounds/chemistry , Prosthesis Coloring , Surface Properties , Zirconium/chemistryABSTRACT
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.
Subject(s)
Dental Porcelain/chemistry , Spectrophotometry , Visual Perception/physiology , Aluminum Silicates/chemistry , Dental Polishing , Differential Threshold/physiology , Faculty, Dental , Humans , Internship and Residency , Light , Potassium Compounds/chemistry , Students, Dental , Surface Properties , Tin Compounds/chemistryABSTRACT
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.
Subject(s)
Dental Caries , Dental Enamel , Composite Resins , Dental Materials , Humans , MolarABSTRACT
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.
Subject(s)
Composite Resins/chemistry , Dental Restoration Failure , Analysis of Variance , Dental Stress Analysis , Hardness , Materials Testing , Statistics, NonparametricABSTRACT
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.
Subject(s)
Dental Bonding , Dental Leakage/etiology , Dentin Permeability/drug effects , Dentinal Fluid/physiology , Oxalates/pharmacology , Acid Etching, Dental/methods , Bisphenol A-Glycidyl Methacrylate , Composite Resins , Dental Bonding/adverse effects , Dental Pulp/physiology , Dental Stress Analysis , Dentin , Dentin-Bonding Agents , Humans , Materials Testing , Molar , Proportional Hazards Models , Survival Analysis , Tensile StrengthABSTRACT
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.
Subject(s)
Acrylic Resins , Denture Bases , Analysis of Variance , Composite Resins , Dental Stress Analysis , Materials Testing , Methacrylates , Pliability , Polymethyl MethacrylateABSTRACT
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.
Subject(s)
Dental Caries/diagnostic imaging , Diagnosis, Computer-Assisted/instrumentation , Image Processing, Computer-Assisted , Bicuspid , Data Display , Dental Restoration, Permanent , Diagnosis, Differential , Humans , In Vitro Techniques , Molar , Predictive Value of Tests , Recurrence , Sensitivity and SpecificityABSTRACT
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.
Subject(s)
Dental Bonding , Dental Enamel/ultrastructure , Dental Leakage/classification , Dental Porcelain/chemistry , Dental Veneers , Dentin/ultrastructure , Resin Cements/chemistry , Acid Etching, Dental , Aluminum Silicates/chemistry , Bisphenol A-Glycidyl Methacrylate/chemistry , Cementation , Dentin-Bonding Agents/chemistry , Humans , Image Processing, Computer-Assisted , Materials Testing , Methacrylates/chemistry , Silver Staining , Temperature , Time FactorsABSTRACT
PURPOSE: To evaluate in vitro the effect of clinical primer application errors on human dentin permeability. The null hypothesis is that there is no difference in dentin permeability reduction with the use of a total-etch three-step (TE3) dentin adhesive system among the treatment groups. MATERIALS AND METHODS: Seventy extracted noncarious human third molars were sectioned to obtain 0.7-mm-thick midcoronal dentin disks. The specimens were randomly assigned to 5 groups and treated with a total-etch three-step (TE3) ethanol/water-based dentin adhesive system, Optibond FL (Kerr; Orange, CA, USA), according to manufacturer's instructions using 4 simulated application errors: short application of primer by immediate drying; no primer application; no drying of primer; aggressive drying of primer. Permeability of dentin was measured as fluid filtration at baseline and after adhesive polymerization. Kruskal-Wallis and Tukey's post-hoc comparisons were used to evaluate permeability reduction differences among groups (alpha = 0.05). RESULTS: The null hypothesis was rejected (p < 0.0001). The data provided strong evidence that the distribution of percentage permeability reduction differed among the 5 treatment groups (p < 0.0001). All possible pairwise comparisons of the groups were statistically significant. The highest mean percentage of permeability reduction was observed in the group where manufacturer's instructions were followed (99.4+/-1.0), followed by the aggressive drying primer group (86.7+/-11.1), the shortened primer application group (73.01+/-12.0), the no-drying primer group (48.44 +/-19.9), and, finally, the no-primer group (22.33+/-7.7). CONCLUSION: The incorrect primer application allowed significant dentin permeability. Strict adherence to recommended clinical application of dentinal adhesives is fundamental to achieve good dentin tubule sealing.
Subject(s)
Dental Bonding/methods , Dentin Permeability/drug effects , Dentin-Bonding Agents/pharmacology , Acid Etching, Dental/methods , Desiccation , Ethanol/pharmacology , Humans , Materials Testing , Phosphoric Acids/pharmacology , Resin Cements/pharmacology , Solvents/pharmacology , Time FactorsABSTRACT
PURPOSE: The purpose of this work was to determine microtensile dentin bond strengths (microTBS) of dentin-resin composite bonds after three-month storage in artificial saliva containing either collagenase (COL) or cholesterol esterase (EST). The null hypothesis tested is that the resin-dentin bond strength is equivalent for each storage medium at the tested storage times. MATERIALS AND METHODS: Resin composite was bonded to occlusal dentin, and microTBS specimens were formed and stored in the artificial saliva, COL, EST, or synthetic oil. After 24 h and 12-week storage, microTBS was determined and failure modes were characterized by SEM. The interfacial ultrastructure was evaluated by transmission electron microscopy as unstained and stained sections (phosphotungstic acid/uranyl acetate). Statistical analysis was performed by ANOVA and Weibull survival analyses at the 0.05 level of statistical significance. RESULTS: There were significantly weaker bond strengths after 12 weeks for all experimental storage media (p < 0.001). Artificial saliva containing EST lowered bond strengths to a significantly greater extent than did COL after 12 weeks of storage, while no difference between these groups could be discerned after 24 h. Therefore, the null hypothesis of this experiment is rejected. CONCLUSION: Exogenous enzymatic challenge to resin-dentin bonds decreased bond durability only with EST. However, when further challenges to ideal infiltration of the comonomers into the hybrid layer were carried out using inadequate removal of solvent, additional alterations in hybrid layer ultrastructure were discerned by TEM that may represent different potential degradative processes. The contribution of endogenous enzymatic challenges to the primary degradative process, ie, hydrolysis, is unknown and deserves continued attention.
Subject(s)
Collagenases/chemistry , Composite Resins/chemistry , Dental Bonding , Dentin/ultrastructure , Sterol Esterase/chemistry , Acid Etching, Dental , Dentin-Bonding Agents/chemistry , Humans , Materials Testing , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Resin Cements/chemistry , Saliva, Artificial/chemistry , Silicon Dioxide/chemistry , Surface Properties , Tensile Strength , Time Factors , Zirconium/chemistryABSTRACT
PURPOSE: The purpose of this study was to assess the bond strength of two self-etching primers (SEP) to ground and unground enamel. MATERIALS AND METHODS: Seventy-two bovine incisors were used in this study. The buccal enamel surface of 36 teeth was ground flat to resemble freshly cut enamel. The rest of the teeth were left intact. Two SEPs--Clearfil SE Bond, Kuraray (CSE) and Prompt L-Pop (3M ESPE) (LP)--and a conventional adhesive system, Scotchbond Multi-Purpose (3M ESPE) (SBMP) as a control, were used to bond a composite button to prepared and unprepared enamel. Microtensile test specimens were trimmed, resulting in a cylindrical cross-sectional area (0.21 mm2 to 0.47 mm2). These specimens were subjected to a tensile force at 1 mm/min until failure. Differences between adhesives and surface preparation were determined by two-way ANOVA. The samples were observed under SEM to evaluate the mode of failure. RESULTS: Bond strength values in MPa (SD) obtained from pooled data in descending order were: SBMP ground 44.54 (5.96), LP unground 42.97 (7.90), CSE unground 41.67 (11.28), LP ground 41.07 (12.07), CSE ground 38.56 (8.78), and SBMP unground 37.60 (9.55). No statistically significant differences were found (p = 0.5061) between surface preparation or adhesive systems. The mean in MPa (SD) of all the specimens that failed at the adhesive joint were: LP unground 47.13 (14.65), SBMP ground 45.28 (7.33), CSE unground 41.40 (11.07), SBMP unground 41.1 (10.04), CSE ground 39.96 (11.83), and LP ground 39.92 (15.45). No statistically significant differences were found (p = 0.5863). Failure occurred mainly at the adhesive interface. CONCLUSIONS: Surface preparation and adhesive treatment had no influence on resin composite microtensile bond strength to bovine enamel.
Subject(s)
Acid Etching, Dental/methods , Adhesives/chemistry , Dental Bonding , Dental Enamel/ultrastructure , Dentin-Bonding Agents/chemistry , Analysis of Variance , Animals , Carbon Compounds, Inorganic , Cattle , Composite Resins/chemistry , Confidence Intervals , Materials Testing , Microscopy, Electron, Scanning , Resin Cements/chemistry , Silicon Compounds , Stress, MechanicalABSTRACT
PURPOSE: To evaluate dentin bond durability using current dentin adhesive resin bonding approaches over a 15-month period of water storage. MATERIALS AND METHODS: Forty-four extracted human molars were polished with 600-grit SiC papers exposing occlusal dentin, and randomly distributed into four adhesive groups: total-etch 3-step (TE3) (Scotchbond Multi-Purpose, 3M ESPE), total-etch 2-step (TE2) (Single Bond, 3M ESPE), self-etch 2-step (SE2) (Clearfil SE Bond, Kuraray), and a self-etch 1-step (SE1) (Prompt L-Pop, 3M ESPE). A resin composite crown was incrementally formed and light cured to approximately 6 mm in height. Microtensile specimens were fabricated and stored in distilled water containing 0.5% chloramine T and tensile tested at 1 mm/min after 1, 6, and 15 months. The debond pathway was recorded as either involving the substrate or joint using scanning electron microscopy. SAS software was used to compute Weibull parameters and distributions, Log-rank and Wilcoxon tests were used for comparison of survival curves over time for each adhesive system and between adhesive systems. RESULTS: The TE2 was significantly weaker than TE3 and SE2 after 1 and 6 months of storage, but all three systems were equivalent after 15 months of storage. The SE1 system could not be tested due to 58 of 65 specimens failing during specimen preparation. Failure modes were observed to be dependent upon adhesive system, with only the total-etch 2-step system demonstrating an increasing involvement in the adhesive joint over time. CONCLUSION: Although differences in bond strength were observed across adhesive systems up to 6 months of storage, no differences were noted at 15 months. This may represent common degradative mechanisms.
Subject(s)
Dental Bonding , Dentin-Bonding Agents/chemistry , Acid Etching, Dental , Bisphenol A-Glycidyl Methacrylate/chemistry , Composite Resins , Crowns , Humans , Linear Models , Materials Testing , Microscopy, Electron, Scanning , Resin Cements/chemistry , Statistics, Nonparametric , Stress, Mechanical , Surface Properties , Survival Analysis , Tensile Strength , Time Factors , Water/chemistryABSTRACT
PURPOSE: The aim of this study was to evaluate: 1) the effect of five dentin desensitizing agents (DDAs) on permeability using hydraulic conductance, and 2) morphological tubule changes with scanning electron microscopy (SEM). MATERIALS AND METHODS: The agents tested were Seal & Protect, Gluma Desensitizer, HurriSeal, D/Sense 2, and Super Seal. Thirty extracted human molars were sectioned into 1-mm mid-coronal dentin disks. Dentin permeability was measured at baseline and after treatment using bovine serum and phosphate-buffered saline at 10 psi. Treatments were applied to the occlusal surfaces of dentin according to the manufacturer's instructions. Representatives from each group were selected for SEM observation. Kruskal-Wallis ANOVA and Tukey's post-hoc comparisons were used to evaluate differences between groups. RESULTS: Mean percent reduction in dentin permeability for each group: SuperSeal = 97.5 +/- 4.0, HurriSeal = 54.2 +/- 35.3, D/Sense 2 = 46.6 +/- 20.4, Gluma Desensitizer = 39.6 +/- 26.7, and Seal & Protect = 33.8 +/- 19.4. The data provided strong evidence of differences in permeability reduction among the agents (p < 0.01). Pairwise comparisons of means demonstrated that the effects of SuperSeal differed significantly from the reductions achieved using Seal & Protect, Gluma Desensitizer, and D/Sense 2. Differences in the degree and content of dentinal tubule occlusion were seen among all DDAs under SEM. CONCLUSION: Of the materials included in this in vitro study, SuperSeal may be the most beneficial when treating dentin sensitivity. The wide range of results may reflect the various approaches and chemistries used to occlude tubules.
Subject(s)
Dentin Permeability/drug effects , Dentin Sensitivity/drug therapy , Dentin/drug effects , Analysis of Variance , Animals , Benzalkonium Compounds/pharmacology , Carbonates/pharmacology , Cattle , Dentin/ultrastructure , Dentinal Fluid/physiology , Glutaral/pharmacology , Humans , Hydrostatic Pressure , Methacrylates/pharmacology , Microscopy, Electron, Scanning , Molar , Oxalic Acid/pharmacology , Phosphates/pharmacology , Resin Cements/pharmacology , Smear Layer , Sodium Fluoride/pharmacology , Statistics, Nonparametric , Surface Properties/drug effectsABSTRACT
One of the authors has used this technique successfully for the past three years in various clinical situations that involve both difficult access anterior and posterior teeth. This is a tooth-structure conserving clinical procedure that can provide a simplified approach for restoring otherwise difficult clinical lesions.
Subject(s)
Dental Restoration, Permanent/methods , Dental Cavity Preparation/classification , Dental Restoration, Permanent/classification , Dental Restoration, Permanent/instrumentation , Glass Ionomer Cements/chemistry , Humans , Matrix Bands , Root Caries/therapy , Rubber DamsABSTRACT
PURPOSE: To compare the microtensile bond strength (microTBS) to enamel of 10 contemporary adhesives, including three one-step self-etch systems, four two-step self-etch systems and three two-step total-etch systems, with that of a conventional three-step total-etch adhesive. METHODS: Resin composite (Z100, 3M) was bonded to flat, #600-grit wet-sanded enamel surfaces of 18 extracted human third molars using the adhesives strictly according to the respective manufacturer's instructions. After storage overnight in 37 degrees C water, the bonded specimens were sectioned into 2-4 thin slabs of approximately 1 mm thickness and 2.5 mm width. They were then trimmed into an hourglass shape with an interface area of approximately 1 mm2, and subsequently subjected to microTBS-testing with a cross-head speed of 1 mm/minute. RESULTS: The microTBS to enamel varied from 3.2 MPa for the experimental one-step self-etch adhesive PQ/Universal (self-etch) to 43.9 MPa for the two-step total-etch adhesive Scotchbond 1. When compared with the conventional three-step total-etch adhesive OptiBond FL, the bond strengths of most adhesives with simplified application procedures were not significantly different, except for two one-step self-etch adhesives, experimental PQ/Universal (self-etch) and One-up Bond F, that showed lower bond strengths. Specimen failures during sample preparation were recorded for the latter adhesives as well.
Subject(s)
Dental Bonding , Dental Enamel/ultrastructure , Dentin-Bonding Agents/chemistry , Resin Cements/chemistry , Silicon Dioxide , Zirconium , Composite Resins/chemistry , Humans , Maleates/chemistry , Materials Testing , Methacrylates/chemistry , Surface Properties , Tensile StrengthSubject(s)
Composite Resins/chemistry , Dental Bonding/methods , Dentin-Bonding Agents/chemistry , Hemostatics/chemistry , Astringents/adverse effects , Astringents/chemistry , Hemostatics/adverse effects , Humans , Propylene Glycols/adverse effects , Propylene Glycols/chemistry , Rhodamines/adverse effects , Rhodamines/chemistryABSTRACT
BACKGROUND: Several all-ceramic restorative systems of various compositions, properties and indications are available to the dental practitioner. Because of the large number of systems, the dental team faces questions and decisions when choosing the appropriate system and the appropriate means of cementation. OVERVIEW: The authors present a brief overview of the cementation options for various types of all-ceramic restorations. In this article, they discuss the cementation of current all-ceramic restorations and make clinical recommendations tailored to each type of ceramic. CONCLUSION AND CLINICAL IMPLICATIONS: The clinician must have a good understanding of the ceramic type to determine whether a restoration should be cemented adhesively or nonadhesively. Other variables, such as isolation and preparation design, also influence the cementation choice. Various ceramic types demand different surface treatments before cementation. Choosing and applying the appropriate surface treatment and cementation procedure will contribute to long-lasting restorations. The literature is lacking in clinical trial results that validate current in vitro data regarding cementation of all-ceramic restorations.