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At least 541 records · Page 30Linked to original sources
PubMed2003

Effect of 2% chlorhexidine on microtensile bond strength of composite to dentin.

PURPOSE: To evaluate the effect of 2% chlorhexidine on the microtensile bond strength of composite resin to dentin treated with three dentin bonding systems. MATERIALS AND METHODS: Flat dentinal surfaces were prepared in 24 extracted human third molars. Teeth were randomly divided into 8 distinct experimental groups according to the adhesive applied (Prime & Bond NT, Single Bond and Clearfil SE Bond), the application (yes/no) of chlorhexidine, and the time point at which it was applied (before or after acid etching the dentin). Composite resin blocks were built up over treated surfaces, and teeth were then stored in water at 37 degrees C for 24 h. Samples were thermocycled, stored under the same conditions, and then vertically sectioned, thus obtaining specimens with 1.0 +/- 0.1 mm2 cross-sectional area. Specimens were stressed in tension at 0.5 mm/min crosshead speed. Bond strength results were evaluated using a one-way ANOVA (p < 0.05). The modes of failures were verified using optical microscopy. Dentin disks were obtained from 3 additional teeth treated in the same manner for observation under SEM. The most representative samples of fractured specimens were also observed under SEM. RESULTS: No statistically significant differences of bond strength values were found between any groups. Failures occurred mainly within the bond; exclusively adhesive fractures (adhesive-dentin) were not observed. CONCLUSION: The 2% chlorhexidine solution, applied before or after acid etching of the dentin, did not interfere with the microtensile bond strength of composite resin to the dentin treated with Prime & Bond NT, Single Bond, or Clearfil SE Bond bonding systems.

Acid Etching, Dental↗
PubMed2006

Bond strength of total-etch and self-etch dentin adhesive systems on peripheral and central dentinal tissue: a microtensile bond strength test.

OBJECTIVE: The purpose of this study was to evaluate the microtensile bond strength (mu TBS) of four total-etch adhesives [Excite (EB), Prime&Bond NT (PBNT), Single Bond (SB), and One Coat Bond (OCB)] by comparing them to five self-etching adhesives (Clearfil SE Bond (CSEB), Xeno III (X III), Prompt L-Pop (PLP), AQ Bond (AQB), and Tyrian/One Step plus (TOSP)] at different dentinal areas. In addition the interface between the adhesive resins and dentin was examined using scanning electron microscopy (SEM). METHODS AND MATERIALS: Superficial occlusal dentin of extracted human molars was exposed and finished with wet 800-grit silicon carbide paper. A block of composite resin was then bonded to the molar samples with the above adhesives according to the manufacturers' instructions. After 24 hours in water at 37 degrees C, the specimens were sectioned into 1 mm thick slices and divided into two regional subgroups according to their relationship to pulp tissue using visual criteria: pulp center and pulp periphery. The slices were then trimmed for the microtensile bond test and subjected to a tensile force and crosshead speed of 1 mm/min. Two-way analysis of variance was performed for statistical analyses. In addition the bond strengths for nine adhesive systems for each dentinal area were compared using the Post-Hoc test. The resin-dentin interfaces for each adhesive system were observed under a SEM. RESULTS: Mean mu TBS ranged from (25.2 MPa) for TOSP to (48.9 MPa) for PBNT. The bond strengths of total-etch adhesive systems were not significantly different, and were higher than self-etch adhesive systems, except for CSEB (p<0.05). No significant regional difference was observed for all of the nine adhesive systems (p>0.05). SEM observation showed there is not a standard hybridization for adhesive systems. CONCLUSION: Different dentinal areas may not exhibit as great an influence on bond strengths using new adhesive systems.

Acid Etching, Dental↗
PubMed2006

Isolation of microbial DNA by newly designed magnetic particles.

Carboxyl group-containing magnetic nonporous poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) (P(HEMA-co-GMA)) microspheres and cobalt ferrite nanoparticles modified with alginic acid (natural carboxylic polysaccharide) were used for isolation of microbial DNA of lactic acid bacteria (LAB) from dairy products, lyophilised cell cultures, and bacterial colonies grown on hard media, and Trichophyton fungi DNA from lyophilised cells. DNA from the samples with lysed cells was reversibly adsorbed to the particles in the presence of high poly(ethylene glycol) (PEG 6000) and sodium chloride concentrations. The optimal final PEG and NaCl concentrations were 9.1 wt.% and 2.0 M, respectively. The adsorbed DNA was released from the particles in low ionic strength TE buffer. The quality of isolated DNA was checked by PCR amplification. Moreover, PCR amplicons were isolated on cobalt ferrite nanoparticles modified with alginic acid and checked by restriction analysis.

Bifidobacterium↗
PubMed2004

Microencapsulation for the gastric passage and controlled intestinal release of immunoglobulin Y.

Avian immunoglobulin (Ig) Y is a promising alternative for the treatment and prevention of enteric infections, and has shown to be effective against a number of gastrointestinal pathogens, including Escherichia coli, Salmonella, and rotavirus. However, its application is limited by its sensitivity to human gastrointestinal conditions. Here, we report on the enteric coating of IgY-containing granules with a pH-sensitive methacrylic acid copolymer. A 35% (w/w) polymer coating was found to protect IgY from gastric inactivation in vitro, maintaining greater than 95% activity after 6 h in simulated gastric fluid. The IgY was slowly released from the microencapsulated granules upon exposure to simulated intestinal fluid, and retained 80% activity after 8 h exposure to pancreatic enzymes. In vivo, using pigs as a model of human digestion, the encapsulated IgY retained significantly more activity than non-encapsulated IgY, indicating that microencapsulation with a methacrylic acid copolymer may be an effective method of protecting IgY from gastrointestinal inactivation, enabling its use for oral passive immunotherapy.

Administration, Oral↗
PubMed2002

A comparison of microtensile bond strengths of several dentin bonding systems to primary and permanent dentin.

OBJECTIVES: Limited information exists with regard to the adhesive ability of glass ionomer cements (GIC) and recently developed resin-based dentin bond systems to primary dentin. The aim of this study was to compare the microtensile bond strength of a conventional GIC (Fuji IX), a resin-modified GIC (Fuji II LC), and two resin-based dentin adhesives (Prime and Bond NT with NRC and Single Bond). The bonded interfaces were also observed using field emission electron microscopy(FE-SEM). METHODS: Microtensile bond test specimens were prepared on superficial dentin of primary and permanent molars. The specimens were bonded according to each manufacturer's instructions except for Prime and Bond NT/NRC which used Silux Plus resin composite instead of Dyract. Hour-glass shaped specimens were created (diameter of 1.2+/-0.02 mm) and stressed in tension at a crosshead speed of 1mm/min. Results were analyzed using two-way ANOVA and LSD test, fracture modes were analyzed using the Mann-Whitney U-test and Kruskall-Wallis test. Twelve specimens were prepared for each material on primary and permanent dentin. Samples were prepared in the same manner, then critical point dried, fractured and sputter-coated for the FE-SEM observations. RESULTS: Two-way ANOVA showed the overall bond strengths were greater for the permanent dentin compared with primary dentin. However, for individual material comparisons no differences among the bond strengths to primary and permanent dentin for Fuji IX (9.7, 12.2 MPa), Fuji II LC (16, 20.1 MPa), Prime & Bond NT/NRC (18.1, 21.6 MPa) and Single Bond (18.2, 21.6 MPa), were detected. However, Fuji IX bond strengths were significantly lower than the other systems tested when bonded to either primary or permanent dentin (p<0.05). Failure mode showed cohesive failure of GIC and mostly adhesive failure for the resin-based adhesives. The FE-SEM observations showed hybrid-like layer formation for the GIC materials and hybrid layer formation for the resin-based adhesives. SIGNIFICANCE: The materials tested would be suitable for bonding to either primary or permanent dentin, but the resin-modified GIC or resin-based systems are likely to provide a stronger bond than the conventional GIC, Fuji IX.

Acid Etching, Dental↗
PubMed2002

Shear bond strength of resin cements to both ceramic and dentin.

STATEMENT OF PROBLEM: All ceramic restorations benefit from resin cement bonding to the tooth. However, the literature is unclear on which cement, ceramic conditioning treatment, and dentin bonding agent produce the highest and longest-lasting bond strength. PURPOSE: This in vitro study evaluated immediate and 6-month shear bond strengths between a feldspathic ceramic and 4 different resin cements with the use of 6 different surface-conditioning treatments. Shear bond strengths between the 4 resin cements and dentin also were measured. MATERIAL AND METHODS: Four hundred eighty discs (10 mm in diameter and 4 mm thick) of Ceramco II porcelain were randomly divided into 6 main groups (n = 80). The ceramic specimens received 6 different surface conditioning treatments before the application of resin cement. These surface treatments were sanding with 600-grit silicon carbide paper, microetching with aluminum oxide, sanding followed by silane application, microetching followed by silane application, hydrofluoric acid-etching, and hydrofluoric acid-etching followed by silane application. Each group then was subdivided into 4 subgroups (n = 20) for the application of 1 of 4 cements: Nexus, Panavia 21, RelyX ARC, and Calibra. All cemented specimens were tested under shear loading until fracture on a universal testing machine; the load at fracture was reported in MPa as the bond strength. Bond strengths were determined at 24 hours and after 6 months of specimen storage in a saline solution. For dentin-resin cement shear bond strength testing, dentin specimens were treated with dentin bonding agents, and a thin layer of resin cement was applied according to the manufacturer's directions. Prodigy composite was bonded to the cement. Shear bond strengths were determined as above and reported in MPa at fracture. Data were analyzed with 3-way analysis of variance (P<.01). RESULTS: Hydrofluoric acid-etching followed by silane application produced bond strengths (15.0 +/- 7.4 to 21.8 +/- 5.8 MPa) in the highest statistical group with all 4 cements at both 24 hours and 6 months (P<.01). Sanding with 600-grit silicon carbide paper and microetching with aluminum oxide produced the lowest bond strengths (0.0 to 4.0 +/- 3.5 MPa). At 24 hours and 6 months, there were no significant differences among the 4 cements when hydrofluoric acid-etching was followed by silane application. Both auto- and light-polymerized dentin bonding agents bonded better to dentin than dual-polymerized bonding agents. CONCLUSION: Within the limitations of this study, hydrofluoric acid-etching followed by silane application produced the best bonds at 24 hours and 6 months with all 4 cements. Auto- and light-polymerized adhesives were associated with higher bond strengths to dentin than dual-polymerized adhesives.

Acid Etching, Dental↗
PubMed1998

Directed polymerization shrinkage versus a horizontal incremental filling technique: interfacial adaptation in vivo in Class II cavities.

PURPOSE: (1) To evaluate the interfacial adaptation to dentin and enamel of Class II composite resin restorations placed in vivo with the directed shrinkage technique, a combination of a self-curing (Bisfil 2B) and a light-curing composite resin (AElitefil); (2) To compare this technique with a horizontal incremental filling technique, where the gingival layer of the light-curing composite resin was cured with a transparent light-tip; (3) To evaluate the effect of a hydrophilic bonding system (All-Bond 2) on the marginal adaptation of both application techniques. MATERIALS AND METHODS: In each of 34 premolars, scheduled to be extracted for orthodontic reasons, a mesial and a distal cavity was restored with composite resin filling material using the directed shrinkage technique (Bisfil 2B/AElitefil) and a horizontal incremental filling technique (AElitefil). In six groups, a hydrophilic dentin bonding system (All-Bond 2) was applied. As control, an enamel bonding agent (Gluma 4) was used in one of the directed shrinkage and in one of the horizontal incremental filling groups. For conditioning of the cavities a 10% phosphoric acid gel was used in six groups and a 32% acid gel in the other two groups. The teeth were extracted after 1 month, sectioned and replicas of the sections were made. Quality of the interfacial adaptation was studied with a scanning electron microscope. RESULTS: On the pairwise comparisons between the two application groups, no significant differences were found between the directed shrinkage technique and the horizontal incremental filling technique. The groups using the hydrophilic bonding system showed a significant better adaptation, with gap-free attachment in 77%-87% of the length of the dentin margins investigated. No significant differences for adaptation to enamel were seen between the investigated groups. The adhesive failures were found mostly between the hybrid layer and the composite resin, while the dentin was still sealed. No significant difference in interfacial quality was seen between the cavities using the 10% or the 32% phosphoric acid conditioning. A relative high frequency of enamel fractures, parallel to the interfaces, was found in the 10% phosphoric acid-conditioned cavities, especially in the cervical enamel interfaces.

Acid Etching, Dental↗
PubMed2006

Clinical performance of posterior compomer restorations over 4 years.

PURPOSE: To clinically evaluate two polyacid-modified resin composites (Hytac and Dyract AP) for the restoration of posterior teeth over a 4-year period and to investigate accessible margins by light microscopy. METHODS: In a controlled prospective clinical study, 71 cavities (21 occlusal, 41 MO/OD, 9 MOD) in 30 patients were restored with compomers by three dentists. Thirty-eight restorations were placed with the combination OSB/Hytac, the same patients received 33 restorations with Prime&Bond 2.1/Dyract AP. Enamel margins of the cavities were etched with phosphoric acid. At baseline, after 12, 24, and 48 months, the restorations were examined by two independent investigators according to modified USPHS-criteria. Focusing on the 40 restorations available at all recalls, a semi-quantitative margin analysis was carried out at each recall using replicas and light microscopy at x130 magnification. RESULTS: Twenty restorations were not investigated at the 4-year recall (drop-out). After 48 months, 11 restorations (Hytac: n = 8, Dyract AP: n = 3) had to be replaced due to tooth fracture (n = 4), gap formation (n = 5), and adhesive failure (n = 2). Forty restorations were still in function after 4 years (overall failure rate 16%; Hytac: 21%; Dyract: 9%). Between the recalls, statistically significant differences were detected for the criteria marginal integrity (Alpha dropping from 76% at baseline to 32% after 4 years), restoration integrity (Alpha ratings at baseline 99% vs. 40% after 4 years), and occlusion (100% vs. 24%). For the criteria surface roughness (from the 6-month recall) and anatomical shape (after 4 years), a significant difference between the materials was evident in favor of Dyract AP. Except gap-free margins, the predominant criterion in the microscopic analysis at baseline was marginal overhang (24%) and 30% negative step formation after 4 years.

Acetone↗
PubMedDate not supplied

Effect of mode of conditioning treatment on efficacy of dentin bonding.

The effect of the mode of application of the Gluma bonding systems' conditioning agents on dentin bonding efficacy was investigated. The reason for this study was the apparent conflict between the manufacturer's instruction to rub the cavity for 30 seconds with a pellet soaked with the conditioning agent and the poor access to some cavity types, which may make it impossible to do so. The efficacy of dentin bonding with or without rubbing conditioning was not different in terms of shear bond strength and marginal cavity adaptation. SEM analysis of the coupling zone showed different resin-impregnated layer thicknesses resulting from the two modes of conditioning. These differences have, however, no impact on the quality of the bond mediated, provided that, as with the Gluma bonding systems, the primer and/or the adhesive resin have perfectly wetted and penetrated the surface collagen and that the degree of polymerization of the resin in the coupling hybrid layer is adequate. The mode of conditioning, therefore, is not critical for dentin bonding with the Gluma systems.

Acid Etching, Dental↗
PubMed1990

Drinking coffee and carbonated beverages blocks absorption of nicotine from nicotine polacrilex gum.

Patients failing to obtain benefit from nicotine polacrilex gum in their efforts to quit smoking may be inadvertently blocking nicotine absorption. Effective nicotine absorption depends on the mildly alkaline saliva that is produced when buffering agents in the polacrilex are released along with nicotine as the polacrilex is chewed. We found that intermittent mouth rinsing with coffee or cola, but not distilled water, substantially reduced salivary pH and nicotine absorption. Because many commonly consumed substances were also found to be highly acidic, we recommend that patients do not ingest any substance during or immediately before nicotine polacrilex use.

Absorption↗
PubMed2001

Sealing and dentin bond strength of adhesive systems in selected areas of perfused teeth.

OBJECTIVES: (1) Test the sealing capacity and tensile strength of various adhesive systems: Scotch Bond 1 (Single Bond in USA)(SB1)+Z100, Syntac Sprint (SYN)+Tetric Ceram, Prime and Bond 2.1 (PB21)+TPH Spectrum, F2000 (Adhesive+Compomer) (F2000) and Optibond Solo (OPT)+Prodigy, to perfused teeth (30 cm distilled H2O), in select areas. (2) Determine the relationship between sealing ability and size of adhesive area (BA) with tensile strength (TS). METHODS: Segments of human third molars (n=67) sealed with amalgam on their coronal side were connected to a perfusion system (30 cm distilled H2O), to measure the basal permeability. Access cavities were drilled through the amalgam to expose dentin (area range: 8.7-20.8 mm2) and measure the permeability of that area. Cavities were sealed with one of the test materials and permeability measured prior to tensile testing. The percentage of decrease in permeability (PPD) that occurred with the different combinations of materials was also measured. RESULTS. TENSILE STRENGTH: there were no statistically significant differences among groups. PERMEABILITY: ANOVA showed that there were statistically significant differences in the mean % decrease in permeability (PPD) among groups (p=0.018). Student-Newman-Keuls test (p<0.05) detected that the mean PPD of F2000 ranked statistically higher than that of SB1. Relationship among variables: a linear correlation was found defined by the formula TS=7.47+0.008 x PPD-0.23 x BA, with a significance of the model p=0.0097. SIGNIFICANCE: None of the materials studied reduced permeability up to 100%. They all produced low tensile bond strengths (maximum mean value of groups: 5.51 MPa (OPT)).

Acetone↗
PubMed2000

Use of one-bottle adhesive as an intermediate bonding layer to reduce sealant microleakage on saliva-contaminated enamel.

PURPOSE: To evaluate the influence of three different adhesives, each used as an intermediary layer, on microleakage of sealants applied under condition of salivary contamination. MATERIALS AND METHODS: Six different experimental conditions were compared, 3 with adhesives and 3 without. After prophylaxis and acid etching of enamel, salivary contamination was placed for 10 s. In Group SC the sealant was applied after saliva without bonding agent and then light-cured. In Group SCA, after saliva, the surface was air dried, and then the sealant was applied and cured. In Groups ScB, SB and PB, a bonding agent (Scotchbond Dual Cure/3M, Single Bond/3M and Prime & Bond 2.1/Dentsply, respectively) was applied after the saliva and prior to the sealant application and curing. After storage in distilled water at 37 degrees C for 24 hrs, the teeth were submitted to 500 thermal cycles (5 degrees C and 55 degrees C), and silver nitrate was used as a leakage tracer. Leakage data were collected on cross sections as percentage of total enamel-sealant interface length. Representative samples were evaluated under SEM. RESULTS: Sealants placed on contaminated enamel with no bonding agent showed extensive microleakage (94.27% in SC; 42.65% in SCA). The SEM revealed gaps as wide as 20 microm in areas where silver nitrate leakage could be visualized. In contrast, all bonding agent groups showed leakage less than 6.9%. Placement of sealant with a dentin-bonding agent on contaminated enamel significantly reduced microleakage (P < 0.0001). The use of a bonding agent as an intermediary layer between enamel and sealant significantly reduced saliva's effect on sealant microleakage.

Acid Etching, Dental↗
PubMed1984

Effect of anionic polymeric hydrogels on spermatozoa motility.

The effects of a few synthetic polymers on the motility of human spermatozoa in vitro have been studied. An alternate copolymer of styrene and maleic anhydride, poly(S-MA), poly (styrene-maleic acid), poly(S-MC), poly(hydroxy-ethyl methacrylate-methacrylic acid) copolymer, poly(HEMA-MAC), poly(HEMA) homopolymer and poly(MAC) homopolymer were chosen for this purpose. It was found that all the carboxylic acid containing polymers are strong inhibitors of the motility of spermatozoa. Poly(HEMA) did not have any inhibitory effect on the motility of spermatozoa.

Contraceptive Agents, Male↗
PubMed1991

An evaluation of different adhesive restorations in cervical lesions.

The restoration of 457 cervical lesions was completed with three different bonding agents. All restorations were divided into two categories. In group A the incisal enamel was neither bevelled nor etched. The lesion was cleaned, followed by the application of the bonding agent and the composite resin. The restorations were finished with a butt joint. In group B, after cleaning procedures, the incisal enamel of all lesions was bevelled and etched, followed by the application of the bonding agent and the composite resin. The restorations were finished to a feather edge. The results from this clinical investigation indicated a high failure rate when only dentinal bonding was involved. The group A restorations suffered from a high rate of loss after 6 months. Moreover, the rate of loss increased over subsequent months. The dentin bonding agents used in combination with micromechanical retention on the enamel border in the group B restorations, however, provided an acceptable clinical result. Not only was the percentage of lost restorations quite low after 6 months, but these bonding systems also offered a more reliable marginal adaptation compared with the enamel bond system. One may conclude that the use of a dentin bonding agent in combination with mechanical retention offers a better chance of clinical success in terms of marginal adaptation, retention, and esthetics.

Acid Etching, Dental↗
PubMed1991

Marginal adaptation of Class V restorations using different restorative techniques.

This in vitro study compares the marginal adaptation of Class V restorations with margins located half in enamel and half in dentine, which were placed using different restorative techniques. Five operative procedures were evaluated both in saucer-shaped erosion lesions and in box-shaped cavities with bevels in enamel. The five procedures included a composite inlay technique using both the chemically and the light curing versions of a resin based composite cement, a bulk placement technique using a chemically curing composite resin, an incremental technique and an incremental technique combined with a built-up base, using a light curing composite resin. A combination of Gluma/Clearfil served as the dentinal adhesive. The micromorphology of the tooth/restoration interface was analysed before and after thermal cycling; the marginal seal was analysed after thermal cycling only. In the conventional cavities, the restorations showed less leakage, and micromorphologically a better, but statistically insignificant superior marginal adaptation. The inlay technique rendered the best marginal quality in both enamel and dentine before and after thermal cycling. Due to the unique curing characteristics of the chemically cured composite resin and cement resulting in a significantly reduced rigid contraction, the inlays cemented with the chemically curing cement and the restorations placed with the chemically curing composite resin were superior to their light cured counterparts. The built-up base yielding a reduction of the composite mass did not enhance marginal adaptation because of the partial replacement of the strong adhesion to dentine mediated by the Gluma/Clearfil combination by the weaker bond promoted by the etched glass ionomer cement.

Acid Etching, Dental↗
PubMed2002

Stability of bisphenol A, triethylene-glycol dimethacrylate, and bisphenol A dimethacrylate in whole saliva.

OBJECTIVES: This study investigated the stability of compounds of dental sealant materials in a salivary matrix. METHODS: Various amounts of bisphenol A (BPA), bisphenol A dimethacrylate (BIS-DMA) or triethylene-glycol dimethacrylate (TEGDMA) were added to whole salivary samples, and stored at -70 degrees C or -20 degrees C for up to 4 months. In other experiments, four separate whole salivary or water samples with BIS-DMA (200 ng/ml) were incubated for 0, 1, 2, 4 or 24h at 37 degrees C. Levels of analytes were determined by capillary gas chromatography/mass spectrophotometry (GC/MS) and high-performance liquid chromatography (HPLC). RESULTS: BPA was stable under all tested conditions. Samples originally containing BIS-DMA had high levels of BPA and almost no BIS-DMA after 4 months at -20 degrees C. Salivary samples incubated at 37 degrees C originally containing only BIS-DMA (200 ng/ml) demonstrated rapid decreases of BIS-DMA and increases of BPA. By 24h, the mean BIS-DMA concentration fell to 21.8 (25) ng/ml, while BPA increased to 100 (48) ng/ml. Only slight decreases in BIS-DMA and no BPA were present in the water samples incubated at 37 degrees C. BPA, BIS-DMA, and TEGDMA were stable if salivary samples were stored at -70 degrees C. Acidification of salivary samples prevented the breakdown of BIS-DMA. SIGNIFICANCE: BIS-DMA is converted rapidly to BPA in the presence of whole saliva. This could account for the findings of BPA in clinical samples collected after the placement of certain sealant products. Decreasing salivary pH and temperature can slow this process and this method should be used for clinical studies of salivary BPA leached from restorative materials.

Acids↗
PubMed1992

Microleakage of glass ionomer/composite resin restorations: a laboratory study. 1. The influence of glass ionomer cement.

Acid-etching of enamel margins, often combined with bevelling and use of a low viscosity resin, has resulted in improved sealing of composite restorations. When enamel is absent and margins involve dentine or cementum, microleakage is more often observed. The use of glass ionomer cement, as both a restorative material and as a base combined with a veneer of composite resin, has been advocated as a means of minimizing microleakage where margins are placed in dentine or cementum. Four restorative techniques incorporating glass ionomer cement were used, in vitro, to restore cervical cavities. After thermal cycling, dye penetration was scored along occlusal and gingival margins. In all instances the gingival margin exhibited a less reliable seal than the occlusal margin. The sandwich restorations produced a superior seal at both occlusal and gingival margins when compared with glass ionomer restorative cement.

Acid Etching, Dental↗