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Effect of saliva contamination on microleakage of a bonding system.

UNLABELLED: Saliva contamination is a major clinical problem during restorative dental treatment. Restorative systems must possess sufficient marginal sealing ability to avoid microleakage. PURPOSE: The purpose of this study was to investigate the effect of saliva contamination on the microleakage of cavities restored with Prime & Bond NT and Dyract-AP. METHOD: Cavities were prepared with occlusal margins in enamel and gingival margins in dentine on the buccal surfaces of extracted human permanent premolar teeth. The cavities were etched with phosphoric acid or a non rinse conditioner (NRC). Preparations were distributed randomly into 4 treatment groups (N = 18) consisting of two respective etching methods (phosphoric acid/NRC), each with and without saliva contamination. After the restorative process the samples were thermocycled in dye, sectioned, and scored for microleakage. RESULTS: Contamination with saliva had no significant effect on microleakage on the enamel or dentine sides where phosphoric acid was used as conditioner. Where NRC was used, significantly more microleakage was observed at the enamel sides, but significantly less at the dentine sides.

Analysis of Variance↗

In vitro evaluation of the cariostatic action of esthetic restorative materials in bovine teeth under severe cariogenic challenge.

Considering that caries around restorations is a serious problem in dentistry, and some restorative materials with fluoride may be important in inhibiting these lesions, this research is aimed at performing an in vitro evaluation of the cariostatic action of some esthetic restorative materials. Standardized cavities were prepared in the center of either intact blocks of bovine enamel or with bovine teeth containing early artificial carious lesions. The specimens were restored with a high viscosity glass ionomer cement (Molar Ketac), a resin-modified glass ionomer cement (Vitremer), a polyacid-modified resin composite (Dyract AP) and a conventional resin composite (Z-250). In addition to the restored specimens, four corresponding control groups were evaluated. All groups, except for two control groups, were subjected to a demineralization/remineralization cycling model for 14 days, simulating a situation of severe cariogenic challenge. The blocks were then longitudinally sectioned through the restorations. Mineral loss was evaluated in these specimens using the Knoop microhardness profiles in longitudinal sections at three different distances of the cavities and at eight distinct depths in relation to the external enamel surface. Statistical analysis of the results showed significant differences (p < 0.05) among the groups, although none of the study materials completely inhibited creation of the lesions. Vitremer demonstrated the best cariostatic action in intact bovine enamel. Ketac Molar, in intact or demineralized enamel, and Vitremer, in demineralized enamel, presented intermediate cariostatic potential. Z-250 and Dyract AP did not demonstrate any cariostatic effect. The data suggests that glass ionomer cements demonstrated better cariostatic action compared to the other restorative materials.

Analysis of Variance↗

Minimally invasive dentistry: bond strength of different sealant and filling materials to enamel.

PURPOSE: The purpose of this study was to evaluate the shear bond strength of different sealant and filling materials, used in minimally invasive dentistry, to human enamel. MATERIALS AND METHODS: Thirty-five sound extracted third molars were selected. The crowns were longitudinally sectioned, embedded in polystyrene resin, and grounded until a flat enamel surface was reached. The samples were assigned into seven groups (n = 10), according to the materials: G1-Fluoroshield; G2-Clinpro; G3-Dyract AP; G4-F2000; G5-Vitremer; G6-Fuji IX; G7-Vidrion F. All materials were applied according to the manufacturer's instructions. The samples were stored in distilled water at 37 degrees C for 24 h and submitted to a shear bonding strength test in a universal testing machine with a crosshead speed of 0.5 mm/min. The failure sites were observed in Scanning Electron Microscopy (SEM). The data were submitted to ANOVA and Tukey's tests (p < 0.05). RESULTS: The mean values (MPa) of shear bond strength were for Fluroshield (25.92 +/- 8.83), Vitremer (20.41 +/- 13.34), Dyract AP (17.08 +/- 6.38), Clinpro (12.82 +/- 8.38), F2000 (8.71 +/- 3.74), Fuji IX (7.64 +/- 2.57), and Vidrion F (4.54 +/- 2.11). Fluroshield resin sealant and Vitremer resin modified glass-ionomer showed statistically higher shear bond strength values than the conventional glass ionomer (GIC) cements. Clinpro and F2000 showed bond strength values with statistical difference only from Fluroshield. The failure mode varied among the groups. The majority of samples presented mixed failure. CONCLUSION: FluroShield and Vitremer showed better performance of shear bond strength to enamel than conventional GIC.

Analysis of Variance↗

Clinical evaluation of a polyacid-modified resin composite in class V carious lesions: 3-year results.

This study evaluated the three-year clinical performance of Class V restorations made of a polyacid-modified resin composite, Dyract. Ninety-two Class V carious lesions in 28 patients were restored with Dyract. Restorations were clinically evaluated at baseline, first, second, and third year recall visits, according to the modified Ryge criteria by two experienced, calibrated examiners. Retention rate after three years in Class V carious restorations was 92.4%, with only seven failed restorations. Color change and marginal discoloration in restorations were found to be statistically significant (p = 0.013 and p < 0.001, respectively) at the end of third year, but none of the affected restorations required replacement. The results of this study revealed that at the end of three years, Dyract exhibited good clinical success rate but significant color change and marginal discoloration in Class V carious lesions.

Adolescent↗

The controlled placement and delayed polymerization technique for the direct Class 2 posterior composite restoration.

Adhesion dentistry and its application to the direct posterior composite restoration is the most controversial topic in dentistry today. The concepts behind this procedure are now the backbone of restorative dentistry. Adhesion dentistry influences basic fillings, crown buildups, post-and-core restorations, cementation, orthodontics, and endodontics. Yet, controversy remains about the correct way to place a direct Class 2 posterior composite restoration. This article will examine the scientific evidence to determine which materials and placement techniques will achieve the optimum direct Class 2 posterior composite restoration at or below the cementoenamel junction using the controlled placement and delayed polymerization technique.

Bicuspid↗

Fluoride release/recharge from restorative materials--effect of fluoride gels and time.

This study examined the differences in fluoride release and recharge among four restorative materials following treatment with APF or neutral fluoride gel for one or four minutes. Specimens were immersed in 2 mL of deionized water, while fluoride release was measured at 24-hour intervals for 15 days using an ion-selective electrode and analyzer. The materials were then treated with the fluoride gels. The fluoride release was measured for 15 days. ANOVA (p<0.05) showed higher fluoride release for Ketac-Fil before fluoride application and for Vitremer and Fuji II LC after application of APF gel. APF gel yielded higher fluoride release when compared to neutral gel, regardless of the material. Fluoride recharge and release was greater after the four-minute APF gel application, with no difference between the times of application for the neutral gel (p>0.05), except for Ketac-Fil. The pattern of release before and after application of the gels was similar and was higher at day 16 compared to day one for the APF gel for resin materials, with higher release at day 15 compared to the initial for Fuji II LC and Vitremer. It was concluded that RM-GICs were the most effective materials with regards to fluoride release after application of APF gel for four minutes.

Acidulated Phosphate Fluoride↗

Sealing ability and bond strength of four contemporary adhesives to enamel and to dentine.

AIM: To compare the shear bond strength and microleakage of four adhesive systems to the enamel and dentine of primary bovine teeth. METHODS: 120 bovine primary mandibular incisors were collected and stored in an aqueous 1% chloramine solution at room temperature for no longer than 3 months after extraction (80 for shear bond testing and 40 for microleakage evaluation). The adhesives tested were Clearfil SE bond (SE), Adper Prompt L Pop (LP), Xeno III (XE), and Prime and Bond NT (PB). For shear bond strength testing the specimens were wet ground to 600 grit SiC paper to expose a flat enamel or dentine surface. After bonding and restoration with Dyract AP (DAP), the teeth were subjected to shear stress using a universal testing machine. For microleakage evaluation, facial class V cavities were prepared half in enamel and half in cementum. All cavities were restored with DAP. After thermocycling and immersion in 2% methylene blue, the dye penetration was evaluated under a stereomicroscope. STATISTICS: All data were analysed by Chi-square tests or Fisher's tests when adapted in order to determine the significant differences between groups. Results were considered as significant for p < 0.05. Results were analysed with an ANOVA test and a Bonferroni's multiple comparison. The level of significance was p < 0.05. RESULTS: Shear bond strength values (MPa,) ranged from: on enamel 11.06 to 5.34, in decreasing order SE, LP, XE and PB and on dentine 10.47 to 4.74, in decreasing order SE, XE, LP and PB. Differences in bond strengths between the four systems on enamel and dentine were all statistically significant, excepted for XE vs LP (shear bond at dentine). No significant differences were recorded in the microleakage degree between the four adhesive systems on enamel and on dentine (p > 0.0.5). CONCLUSIONS: The highest shear bond strength was achieved by Clearfil SE bond and the lowest by Prime and Bond NT. There was no significant difference concerning the sealing ability of the four adhesive systems.

Animals↗

Five-year clinical evaluation of Dyract in small Class I cavities.

PURPOSE: To evaluate the 5-year clinical performance of Dyract in small Class I cavities in non stress-bearing areas. METHODS: On 36 patients, 87 restorations needing small cavity preparations were performed. The lesions were diagnosed macroscopically with a probe. They involved shallow fissures, and had reached dentin but the lateral spread was limited and localized in dentin. Cavities were designed to be on non stress bearing areas. Cavities' average facio-lingual width were prepared to be 1/3 or less than the intercuspal width. At baseline, 1-, 2-, 3-, 4- and 5-year recalls, the restorations were evaluated according to the modified Ryge criteria by two calibrated, experienced examiners. RESULTS: None of the restorations was lost and retention rate was 100% at the end of 1 year. After 2 years, one restoration (1.2%) had to be replaced due to caries lesion adjacent to its margin and the rate of retention was 98.8%. At the 3-year recall, four restorations, at the 4-year, one restoration and at the 5-year, one restoration had caries lesions adjacent to their margins and the cumulative retention rates were 94.2%, 92.9% and 91.5% respectively. Significant differences were detected between all of the evaluation periods in regard to color match rate (P = 0.00001), with the exception of rate between the baseline and 1 year evaluations. In regard to the marginal discoloration rates, there were statistically significant differences (P = 0.00001) between all of the evaluation periods with the exception of rates between the baseline and 1-year, 3- and 4-year, and 4- and 5-year results. Except for the failed restoration, no other restoration was clinically unacceptable in regard to color match, wear or loss of anatomic form, marginal discoloration, caries, marginal adaptation and surface texture.

Adolescent↗

Evaluation of shear bond strength and SEM observation of all-in-one self-etching primer used for bonding of fissure sealants.

OBJECTIVES: To evaluate and compare enamel shear bond strength of an all-in-one self-etching primer (Prompt L-Pop) to regular acid etch material when bonded to two-fissure sealant systems (Concise and Dyract Seal). METHOD AND MATERIALS: Forty newly extracted non-carious first permanent molars were embedded in a Teflon mold. The teeth were divided into four groups and each consisted of ten specimens. The bonding surfaces were treated with either Prompt L-Pop as recommended by the manufacturer or etched with phosphoric acid. After 24 hours of water storage, the specimens were evaluated for shear bond strength using an Instron testing machine. Scanning electron microscope (SEM) examinations were carried out to evaluate the failure sites of the sealants. RESULTS: The mean shear bond strengths using Prompt L-Pop were Concise: 23.46 MPa and Dyract Seal: 20.34 MPa. These values were higher than and statistically different from those of Dyract Seal (9.99 MPa) and Concise (8.85 MPa) when phosphoric acid was used. The failure was predominantly of the adhesive type. The SEM examination showed the failure of debonding was predominantly related to the type of etching systems used rather than the type of fissure sealants. CONCLUSION: The use of the all-in-one self-etching adhesive Prompt L-Pop improves the mean enamel shear bond strength of fissure sealants.

Acid Etching, Dental↗

Bond strength of 4 sealants using conventional etch and a self-etching primer.

PURPOSE: The purpose of this study was to determine and compare the shear bond strength of 4 fissure sealant systems (Dyract Seal, Concise, Visio-Seal, Helioseal) to enamel using conventional etch and self-etching primer (Prompt-L-Pop). METHODS: Fifty-six newly extracted noncarious first permanent molars were used and embedded in a Teflon mold (3-mm height, 3-mm internal diameter). Mesial surfaces were exposed to a flattened area of enamel and then dried and washed. The teeth were divided into 8 groups, each consisting of 7 specimens stored in 37 degrees C distilled water for 24 hours. Then specimens were tested in a shear mode (Instron) at a crosshead speed of 0.5 mm/minute. The mean and standard deviations were subjected to an analysis of variance. RESULTS: The average bond strengths using Prompt-L-Pop were: (1) Dyract Seal=20.61 MPa; (2) Concise=23.42 MPa; (3) Visio-Seal=2.94 MPa; and (4) Helioseal=11.83 MPa. These values were higher than and statistically different from those of Dyract Seal (10.18 MPa) and Concise (9.17 MPa) when the conventional etch system was used (student t test, P<.001). CONCLUSION: The bond strengths of Prompt-L-Pop, in conjunction with Dyract Seal and Concise fissure sealant materials, exceeded those of conventional etch.

Acid Etching, Dental↗

Clinical evaluation of a polyacid-modified resin composite (Dyract) in Class III cavities: 5-year results.

PURPOSE: This study evaluated the 5-year clinical performance of Dyract polyacid-modified resin composite material in Class III cavities. METHODS: 62 Class III cavities in 30 patients were restored with Dyract. Two experienced, calibrated examiners evaluated the restorations clinically at baseline and at 1-, 2-, 3-, 4-, and 5-year recalls, according to the modified Ryge criteria. RESULTS: After 5 years, a total of six restorations had failed and the cumulative failure rate was 94.6%. By the 5-year recall, one restoration was replaced due to pulpitis and five were replaced due to secondary caries. After 5 years, marginal discoloration was statistically significant (P= 0.0002).

Acid Etching, Dental↗

Clinical evaluation of a polyacid-modified resin composite (Dyract AP) in Class I cavities: 3-year results.

PURPOSE: This study evaluated the 3-year clinical performance of the polyacid-modified resin composite Dyract AP in restorations for Class I carious lesions. METHODS: 108 Class I cavities in 21 subjects were restored with Dyract AP. The lesions, which were diagnosed macroscopically with a probe, involved fissures and had reached the dentin, while lateral spread was limited and localized to the dentin. The average facio-lingual width of the cavities was equal to or less than one-third the intercuspal width. Restorations were evaluated clinically by two experienced, calibrated examiners at baseline and at 1, 2, and 3 years, according to the modified Ryge criteria, (color match, marginal discoloration, wear or loss of anatomical form, caries, marginal adaptation, and surface texture). RESULTS: None of the restorations failed at the end of the first year. At 2 years, two restorations required immediate replacement due to caries lesions adjacent to the margins. At 3 years, six restorations had caries lesions adjacent to their margins, and the cumulative rate of success was 93.4%. Color changes and marginal discolorations were found to be statistically significant (P < 0.001) at 3 years, although none of the restorations needed to be replaced. Significant differences were also observed in the caries rate (P < 0.001) at 3 years. Aside from the eight failed restorations, the degrees of color matching, marginal discoloration, wear or loss of anatomical form, caries, marginal adaptation, and surface texture were clinically acceptable at 3 years post-treatment.

Acid Etching, Dental↗

Surface antibacterial properties of resin and resin-modified dental cements.

OBJECTIVE: Cements possessing antibacterial properties may reduce bacteria-induced fixed partial denture complications. The purpose of this study was to evaluate the antibacterial properties of 4 dental cements using the direct contact test (DCT) and the agar diffusion test (ADT). METHOD AND MATERIALS: The ADT was performed using mitis salivarius agar plates. Each plate was evenly inoculated with freshly grown mutans streptococci. Two samples of each test material-RelyX ARC, Variolink II, GC FujiCEM, and Principle-were placed, and the inhibition halo obtained was measured after 48 hours. For the DCT, 8 samples were placed on the sidewalls of wells in a 96-well microtiter plate. After polymerization, freshly grown Streptococcus mutans cells (1 X 10(6)) were placed on the surface of each sample for 1 hour at 37 degrees C. Fresh medium was then added to each well, and bacterial growth was followed for 16 hours in a temperature-controlled spectrophotometer. Similarly prepared samples were aged in phosphate-buffered saline for 1 or 7 days and the DCT was repeated. Analysis of variance (ANOVA) and Tukey multiple comparisons were applied to the data. RESULTS: In the ADT, GC FujiCEM showed an inhibition zone of 2.0 +/- 0.3 mm, and Principle showed an inhibition zone of 1.2 +/- 0.2 mm. In the DCT, freshly polymerized samples of GC FujiCEM and Principle exhibited potent antibacterial properties, while samples of Variolink II and RelyX ARC showed moderate antibacterial properties. Principle showed some antibacterial properties even after 1 day (P < .001). CONCLUSION: None of the tested cements in this study possesses long-term antibacterial properties.

Analysis of Variance↗

Bond strength of resin-reinforced glass ionomer cements after enamel etching.

This study evaluated the shear bond strength of resin-reinforced glass ionomers to enamel etched or unetched. Human, non-carious extracted permanent molars stored in distilled water were used. Flat buccal and lingual enamel surfaces were ground wet on 600-grit silicon carbide paper. The teeth were then distributed at random into six groups of 5 teeth (10 surfaces) each: Group 1: Fuji II LC, no enamel etching; Group 2: Fuji II LC, enamel etched with 10% phosphoric acid for 10 seconds; Group 3: Dyract, no enamel etching; Group 4: Dyract, enamel etched with 10% phosphoric acid for 10 seconds; Group 5: Photac-Fil, no enamel etching; Group 6: Photac-Fil, enamel etched with 10% phosphoric acid for 10 seconds. Cylindrical samples of the glass ionomers were prepared in plastic molds and bonded to the enamel surface according to the manufacturers' instructions. All samples were placed in distilled water for 24 hours, and sheared with an Instron at a crosshead speed of 0.5 mm/minute. The results (in MPa) were: Group 1: 11.29 +/- 4.84; Group 2: 19.64 +/- 5.43; Group 3: 8.26 +/- 3.61; Group 4: 22.04 +/- 5.40; Group 5: 2.05 +/- 3.05; Group 6: 9.12 +/- 6.61. ANOVA and Student-Newman-Keuls procedure revealed that on etched enamel, Fuji II LC and Dyract had a significantly higher bond strength than all the other groups tested (P < 0.0001), but not significantly different between each other. With these two groups, cohesive failure within the material was recorded in all samples while in the unetched samples, all specimens displayed an adhesive failure (glass ionomer-enamel interface). All samples with Photac-Fil, with or without enamel etching had adhesive failures.

Acid Etching, Dental↗

Dentin bond strength of fluoride-releasing materials.

PURPOSE: To evaluate the shear bond strength to dentin of fluoride-releasing materials. MATERIALS AND METHODS: Human, noncarious extracted permanent molars stored in distilled water were used. Flat buccal and lingual dentin surfaces were ground wet on 600-grit silicon carbide paper. The teeth were then distributed at random into four groups of 5 teeth (10 surfaces) each: Group 1: Fuji II LC; Group 2: Vitremer; Group 3: VariGlass; Group 4: Dyract. Cylindrical samples of the glass ionomers were prepared in plastic molds and bonded to the dentin surface according to the manufacturers' instructions. All samples were placed in distilled water for 24 hours, thermocycled for 500 cycles in distilled water at 5 degrees C and 55 degrees C and sheared with an Instron at a crosshead speed of 0.5 mm/minute. RESULTS: In MPa: Group 1: 15.96 +/- 3.28; Group 2: 9.70 +/- 2.43; Group 3: 13.48 +/- 3.35; Group 4: 21.14 +/- 5.32. ANOVA revealed that Dyract had a significantly higher bond strength than all the other products tested (P < 0.0001). Vitremer had a significantly lower bond strength. Fuji II LC had no significant difference from VariGlass. Fracture patterns, examined with the SEM, were cohesive within the cement for all groups.

Acrylic Resins↗

Influence of dentin conditioning on bond strength of light-cured ionomer restorative materials and polyacid-modified composite resins.

The purpose of the study was to evaluate the dentin bond strength of restorative materials containing both glass ionomer and composite resin components. Three resin-modified glass ionomer restorative materials (Fuji II LC, Photac-Fil, Vitremer), three polyacid-modified composite resins (Dyract, Ionosit Fil, VariGlass VLC), a hybrid composite (blend-a-lux) and a chemical-cured glass ionomer cement (ChemFil Superior) were investigated for dentin tensile bond strength with and without conditioning of the tooth surfaces. For each material, tensile bond strength was determined using five conditioned and five unconditioned bovine tooth specimens. Conditioning of the specimens was performed according to the manufacturers' instructions. The tensile bond strength was tested with a universal testing machine. Statistical analysis was performed with analysis of variance, the Scheffe's-test and the Student's t-test. All materials showed higher adhesion to conditioned dentin than to unconditioned specimens. Except for Photac-Fil, the bond strength to conditioned dentin of all resin-modified glass ionomer restorative materials and polyacid-modified composite resins was higher as compared to the chemical-cured glass ionomer and the hybrid composite. However, these differences were not statistically significant. All polyacid-modified composite resins resulted in higher bond strengths to conditioned dentin as compared to the resin-modified glass ionomer restorative materials. These differences were statistically significant only for VariGlass VLC as compared to Photac-Fil. In order to improve adhesion of the tested materials to dentin it is highly recommended to follow the manufacturers' instructions concerning dentin conditioning.

Acrylic Resins↗