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At least 163 records · Page 9Linked to original sources
PubMed2006

Influence of conditioning time on enamel adhesion.

OBJECTIVE: The aim of this study was to calculate enamel bond strengths of 4 self-etch adhesives in function of conditioning time. METHODS AND MATERIALS: Sixty proximal surfaces of 30 extracted human molars were roughened and assigned to 4 self-etch adhesives: AdheSE (Ivoclar Vivadent), Adper Prompt L-Pop (3M Espe), Clearfil SE Bond (Kuraray America), and Tyrian SPE/One-Step Plus (Bisco). Prime & Bond NT (Dentsply) was used as the total-etch control. For 30 surfaces, the adhesives were applied per the manufacturers' directions. For the remaining 30, enamel was conditioned for twice the time recommended by the manufacturer. Buildups were constructed with Filtek Z250 (3M ESPE). Bonded specimens were sectioned in sticks and tested to tensile failure. Data were analyzed with 2-way ANOVA and Duncan's test at P < .05. The pH of the self-etch solutions and the phosphoric acid gel was measured with a pH meter. A correlation coefficient was computed to measure the linear association between pH and bond strengths. RESULTS: Tyrian SPE and Prime & Bond NT, the adhesives whose acidic conditioners yielded the lowest pH, ranked in the highest subset regardless of application time. AdheSE and Clearfil SE Bond, which had the highest pH, were the only adhesives for which double application time resulted in statistically higher bond strengths than the recommended time. When means were pooled for application time, Tyrian SPE and Prime & Bond NT resulted in bond strengths that were significantly higher than those of the remaining adhesives. AdheSE resulted in statistically lower bond strengths than any other adhesive. A significant correlation was found between pH and mean bond strengths. CONCLUSION: Doubling the enamel conditioning time might increase bond strengths for specific self-etch adhesives.

Acid Etching, Dental↗
PubMed1985

Synthesis of poly-L-glutamates containing 5-substituted uracil moieties.

The polymer reaction of cyclic derivatives of uracil and 5-bromouracil with polyacrylic and polymethacrylic acids, and poly-L-glutamic acid was studied in dimethylformamide solution. A similar reaction of cyclic derivatives of uridine with the polymeric acids was also made. Alkaline hydrolysis was further carried out on the polymers obtained.

Indicators and Reagents↗
PubMedDate not supplied

[Antisilicotic action and side effects of polypyridylethyl-methacrylate iodomethylate].

Antisilicotic and side effects of a new polymer synthetized on the basis of polymethacrylic acid were studied. The polymer not only inhibited the development of silicotic sclerosis but also induced its partial reverse development. As regards the effect intensity it appeared to be equal to highly effective polyvinylpyridine-N-oxide. The data obtained indicate the necessity of a further study of the new antisilicotic polymer with a purpose of recommending it for clinical trials.

Animals↗
PubMed1994

Bond strengths of dentinal bonding systems to enamel and dentin.

Contemporary, third-generation dentinal bonding products have become highly specialized in producing high bond strengths to dentin. This investigation compared in vitro bond strengths of six dentinal bonding systems and their matched composite resins to human enamel and dentin. The effects of treatment by dentinal primers on enamel bond strengths as well as the effects of phosphoric acid on the strengths of dentinal bonds were measured. The use of dentinal primer on enamel improved the bond strengths of Prisma Universal Bond 3/Prisma APH and XR Bond/Herculite systems and had no effect on Denthesive/Charisma, Scotchbond 2/Silux, and Tenure/Perfection, while the enamel bond strengths of Gluma/Pekalux declined. Pretreatment of dentin with phosphoric acid improved the bond strengths of Denthesive/Charisma, Prisma Universal Bond 3/Prisma APH and XR Bond/Herculite, but had no effect on Gluma/Pekalux, Scotchbond 2/Silux and Tenure/Perfection.

Acid Etching, Dental↗
PubMed1995

Effect of acid etchant composition and etch duration on enamel loss and resin composite bonding.

PURPOSE: To investigate the effects of different acid etchants' ability to condition enamel as gently as possible to remove a minimum of substance only, to produce a highly retentive pattern, and finally to ensure frosty appearance of the etched enamel for clinical control of the procedure. MATERIALS AND METHODS: Two commercial uni-etch gels, Gluma 2000-1 and Scotchbond Multi-Purpose Etchant, were studied together with gels of 5, 10, 20 and 35% phosphoric acid and varying amounts of thickening agents in the 20% gel. Enamel loss was measured with a contact-free method by materials and etch duration, and the shortest etching times for dull frosty enamel appearance were determined. Shear bond strength (SBS) was measured after 24 hours' storage in water. RESULTS: Enamel loss was very low with the commercial agents and increased with H3PO4 concentrations and with etch duration. While the commercial compounds produced no frosty enamel even after 120-second etch duration, the phosphoric acids produced frosted enamel after 15, 30, 60 and 120-second application of 35, 20, 10 and 5% acids, respectively. All etchants and etch durations tested produced effective retentive patterns. No differences in SBS were noted, and the failure modes were consistently cohesive in resin.

Acid Etching, Dental↗
PubMed1994

Analysis of dental adhesive systems using scanning electron microscopy.

This study used scanning electron microscopy (SEM) to evaluate the effects of various acid conditioners (etchants) on dentine surfaces. The conditioners completely removed the smear layer from dentine and opened the dentinal tubules, but some also left debris or a reaction product on the surface. The study also evaluated the resin-dentine interfaces produced by five new-generation dentine bonding systems: All-Bond 2, Amalgambond, Gluma 2000, OptiBond, and Scotchbond Multi-Purpose. All-Bond 2, Amalgambond, OptiBond, and Scotchbond Multi-Purpose formed acid-resistant hybrid layers and intra-tubular resin tags when they were applied to visibly moist dentine.

Acid Etching, Dental↗
PubMed1994

Gluma bond strength to the dentin of primary molars.

The purposes of this study were to measure and compare etching patterns, tensile bond strengths and fracture patterns of Gluma/Lumifor system to the buccal dentin of primary molars following application of Gluma cleanser and 37% phosphoric acid. The tensile bond strength of Gluma/Lumifor to the buccal dentin following application of Gluma cleanser averaged 5.53 +/- 3.27 (x +/- SD MPa) which is significantly greater than bond strength following application of only 37% phosphoric acid 2.04 +/- 0.67. Etching ground buccal dentin surfaces with 37% phosphoric acid has no significant different effect on the bond strength of Gluma/Lumifor combination. Gluma cleanser showed effective removal of the smear layer and partial plugging of the dentinal tubules, while 37% phosphoric acid showed complete removal of the smear layer creating opened dentinal tubules.

Acid Etching, Dental↗
PubMed1993

Effects of etching time on enamel bond strengths.

This study evaluated the effects of etching time on bond strengths of composite to enamel. Proximal surfaces of extracted molars were etched with either a conventional etchant (35% phosphoric acid) or one of two dentin/enamel conditioners, 10% maleic acid (Scotchbond Multi-Purpose Etchant), or a solution of oxalic acid, aluminum nitrate, and glycine (Gluma 1 & 2 Conditioner). Each agent was applied for 15, 30, or 60 seconds. Specimens etched with 35% phosphoric acid had the highest mean bond strengths at each etching time. At the manufacturer's recommended application times, the other two agents gave significantly lower shear bond strengths than phosphoric acid.

Acid Etching, Dental↗
PubMed1993

Shear bond strengths of new enamel etchants.

Many dental adhesive systems now rely on simultaneous etching of enamel and dentin. Instead of the traditional 35-40% phosphoric acid, new etchants (including 10% maleic acid, 10% phosphoric acid, and oxalic acid/aluminum nitrate) are used. This in vitro study determined the shear bond strengths of resin composite to enamel which was etched with these agents according to manufacturers' instructions. The control etchant, 35% phosphoric acid, gave a mean bond strength of 24.5 MPa. 10% maleic acid and 10% phosphoric acid had significantly lower shear bond strengths (13.2 MPa). Gluma 1 & 2 Conditioner (oxalic acid/aluminum nitrate) had a mean bond strength of 6.3 MPa, which was significantly less than the other etchants. Bond strengths for each etchant were not affected by the type of unfilled resin used.

Acid Etching, Dental↗
PubMed1994

Dimensional stability and reproduction of surface detail of tissue conditioning materials.

Four commercial tissue conditioners have been assessed in terms of their dimensional stability and ability to reproduce surface detail according to ADA specification #19 for impression materials. Results have been compared with those of a number of elastomeric impression materials. The tissue conditioners performed adequately and as such could be used as impression materials within 24 hours of their application. While they did not compare well with the elastomeric impression materials they comply with the limitations of the ADA specifications. It is suggested that standards specific to these materials should be developed.

Acrylic Resins↗
PubMed1995

Phosphoric acid as a conditioning agent in the Gluma bonding system.

PURPOSE: To investigate the effect of phosphoric acid conditioning gels on compatibility with the Gluma dentin bonding system. MATERIALS AND METHODS: Sheer bond strengths (BS), marginal performance in dentin cavities and microleakage resistance in mixed cavities were used as target parameters to determine the efficacy of Gluma/Pekafill on dentin pretreated with conditioners of 5, 10, 20 or 35% H3PO4 and different amounts of silica (0, 5 and 10%) after 15, 30 60 or 120-second treatment duration. The thicknesses of the hybrid layers were determined along the dentin cavity margin by light microscopy. RESULTS: Neither the phosphoric acid concentration and the silica content nor the conditioning times tested had a significantly different effect on SBS or marginal performance (P > 0.05). There was no relationship between the hybrid layer thickness and the target parameters either. The SBS recorded on dentin were in the same order of magnitude as previously found on acid etched enamel (+/- 17 MPa). The marginal performance and microleakage results after thermocycling proved adequate dentin bonding and cavity sealing. Phosphoric acid etching of dentin is compatible with the gluma bonding system.

Acid Etching, Dental↗
PubMed1995

Function of the hybrid zone as a stress-absorbing layer in resin-dentin bonding.

The effects of dentinal surface conditioning with phosphoric acid or with phosphoric acid and subsequent deproteinization by sodium hypochlorite on resin bonding are presented. Bond strengths mediated by the Gluma/Pekafill bonding and restorative system were not affected by the alternative pretreatment methods, while marginal performance of restorations in dentinal cavities was significantly adversely affected by the deproteinization procedure. The resin polymer coupling zone has an important function as a layer that compensates for the curing stresses of the restorative material that act in a wall-to-wall direction.

Acid Etching, Dental↗
PubMed1996

Microleakage of bonding agents with wet and dry bonding techniques.

PURPOSE: To assess the microleakage of Class V preparations restored with three bonding agents using wet and dry bonding. MATERIALS AND METHODS: Cavities were prepared in the buccal and lingual surfaces of extracted human premolar teeth and restored with resin composite after application of the dentin bonding agents, using a wet or dry bonding technique. The teeth were stored for 2 weeks at 37 degrees C, thermocycled, and the restorations examined for leakage using buffered methylene blue as the marker. The teeth were sectioned bucco-lingually through the restorations and the degree of microleakage assessed microscopically. RESULTS: All groups showed leakage at both the dentin and enamel margins. There was no significant difference in leakage at the enamel margins between groups (p > 0.05) and no significant differences in leakage between the wet bonding (P > 0.05) or dry bonding (P > 0.05) procedures. However, when comparing the effects of wet and dry bonding, there was less leakage at the gingival margin in the groups where the bonding agent was acetone-based and wet bonding was used (P < 0.03). There was no significant difference in leakage for Scotchbond Multi-Purpose Plus when either maleic acid or phosphoric acid was used as the etchant (P > 0.05).

Acid Etching, Dental↗
PubMedDate not supplied

Enamel and dentin bond strength and bonding mechanism to dentin of Gluma CPS to primary teeth.

This study evaluated the shear bond strength to enamel and dentin and bonding mechanism to dentin of Gluma CPS bonding system to primary teeth enamel and dentin. Pekafill hybrid composite was used. Ten specimens were immersed in deionized water at 37 degrees C for twenty-four hours and ten other specimens were subjected to a thermocycling procedure (2000 cycles between 5 degrees and 55 degrees C, dwell time fifteen seconds). After water storage or thermocycling, the bonded cylinders were sheared and the bond strength calculated. After debonding, the failure sites of all samples were evaluated microscopically. The data were analyzed with an ANOVA and Student-Newman-Keuls test. In ten other primary molars, the buccal surfaces were ground flat on wet SiC papers to expose peripheral dentin. Cylindrical buttjoint cavities were prepared with a cylindrical diamond bur. The cavities were treated with Gluma CPS and filled with pekafill as described above. After fifteen-minute water storage, filling excess was removed and marginal integrity and bonding mechanism of five restorations was examined with a light microscope. Five other restorations were evaluated after storage in water at 37 degrees C for twenty-four hours. Maximal gap widths and hybrid layer thickness were determined. The results showed that thermocycling did not affect the shear bond strength to enamel or dentin. There was a statistically significant difference (p < 0.05) between the shear bond strength values obtained in enamel and dentin. The maximal gap width was not significantly different between specimens that were stored in water for fifteen minutes or twenty-four hours. The average hybrid layer thickness was 11.7 +/- 1.1 micrograms. All specimens revealed a resin cohesive failure very close to enamel or dentin surface. The etch patterns produced on the abraded enamel surface were uniform and deeper as compared to the sample that was pumiced. This was also confirmed in the epoxy replicas.

Acid Etching, Dental↗
PubMed1997

Transdermal nicotine suppresses cutaneous inflammation.

BACKGROUND: Cigarette smoking significantly alters the inflammatory response in the skin following application of irritants and rubefacients. The mechanism of this effect is unknown. There are thousands of components in cigarette smoke that may be pharmacologically important, but there is evidence to suggest that nicotine may play an important role in the observed effect on the inflammatory process. DESIGN: This was an interventional study to assess cutaneous responsiveness to different stimuli after transdermal nicotine administration in volunteer subjects. Cutaneous testing was performed at baseline and at weeks 2 and 4 (the end) of the study. SETTING: The department of Dermatology, University Hospital of Wales, Cardiff. PARTICIPANTS: Ten lifelong nonsmokers were recruited for the study. INTERVENTION: Nicotine patches were applied daily for 1 month. MAIN OUTCOME MEASURES: The following tests were performed: application of 2 times the minimal irritancy dose of sodium lauryl sulfate, irradiation with 2 times the minimal erythema dose of UV-B, measurement of cutaneous vasodilation following application of ethyl and hexyl nicotinate, and reactive hyperemia following arterial occlusion. RESULTS: There was a significant reduction in the cutaneous inflammatory response to sodium lauryl sulfate (P < .001) and irradiation with UV-B (P < .003) and a reduction in reactive hyperemia (P < .03) after 2 weeks of treatment, which returned values to normal at 4 weeks. There was no change in blood flow following application of topical nicotinates. CONCLUSIONS: Nicotine administration via a transdermal delivery system suppresses the cutaneous inflammatory response to sodium lauryl sulfate and UV-B, as well as triggers a transient suppression of reactive hyperemia following arterial occlusion. The apparent anti-inflammatory effects of smoking cigarettes can therefore only partially be explained as a long-term effect of nicotine.

Administration, Cutaneous↗
PubMedDate not supplied

Bond strength and interfacial micromorphology of four adhesive systems in primary and permanent molars.

The purpose of this study was to assess the dentin bond strength of four adhesives and the interfacial micromorphology in primary and permanent teeth. Thirty-two for each primary and permanent molar were divided into four groups. Buccal and lingual dentin surfaces were wet ground up to 600 grit. The teeth were bonded following the manufacturers' instructions, thermocycled (500x), mounted on plaster and sheared with instron machine. Some teeth were sectioned for SEM evaluation. The mean bond strengths (in MPa) for primary and permanent teeth respectively were: Scotchbond Multipurpose 19.4 +/- 4.0, 18.9 +/- 4.8; One Step 30.6 +/- 3.6, 35.6 +/- 1.9, Prime and Bond 2.1 28.3 +/- 4.8, 31.8 +/- 4.0, EBS Bond 31.5 +/- 4.6, 33.6 +/- 4.8. There was no significant difference between the last three adhesives nor between primary and permanent teeth except with One Step. All the adhesives formed a hybrid layer which was wider in permanent teeth. It was concluded that the products tested produced a strong bond strength to dentin and may function well clinically. The bond strength was not totally dependent on hybrid layer formation.

Adhesives↗
PubMedDate not supplied

Enamel bond strengths of "one-bottle" adhesives.

PURPOSE: Several "one-bottle" dental adhesives recently have been introduced. These contain hydrophilic resin monomers that should readily wet tooth surfaces. Most also contain solvents that could increase enamel bond strengths by driving out residual moisture from enamel and increasing resin penetration. The purpose of this study was to evaluate bond strengths obtained by six one-bottle bonding agents and one conventional unfilled resin (control). METHODS: Seventy bovine teeth were randomly assigned to seven groups of 10. Enamel was etched for 15 s with 35% phosphoric acid. Following application of the adhesive, composite resin was bonded using a gelatin capsule technique. Shear bond strengths to enamel were determined. RESULTS: Mean bond strengths ranged from 14.2 MPa for Syntac Single-Component to 27.8 MPa for Single Bond. The mean for Syntac Single-Component was significantly less than that of all other systems tested. CONCLUSION: The results of this study indicate that one-bottle bonding agents, with the exception of the Syntac material, provide enamel bond strengths at least equal to that of a conventional unfilled resin.

Acid Etching, Dental↗