Comparison of marginal sealing ability of new generation bonding systems

Microleakage and characteristics of resin-tooth tissues interface of a self-etch and an etch-and-rinse adhesive systems

Objectives

This study was conducted to compare the microleakage and characteristics of the resin-tooth tissue interface between self-etch and etch-and-rinse adhesive systems after 48 hours and 3 months.

Materials and Methods

40 extracted premolar teeth were randomly divided into 2 groups: 1-step self-etch adhesive system – Optibond™ All-In-One, and 2-step etch-and-rinse adhesive system - Adper™ Single Bond 2. Both groups were subjected to 500 thermocycles (5°C–55°C) before scanning electron microscope (SEM) analysis or microleakage trial at 48-hour and 3-month time periods.

Results

SEM images showed the hybrid layer thickness, diameter, and length of resin tags of the self-etch adhesive (0.42 ± 0.14 µm; 1.49 ± 0.45 µm; 16.35 ± 14.26 µm) were smaller than those of the etch-and-rinse adhesive (4.39 ± 1.52 µm; 3.49 ± 1 µm; 52.81 ± 35.81 µm). In dentin, the microleakage scores of the 2 adhesives were not different in both time periods (48 hours/3 months). However, the microleakage score of etch-and-rinse adhesive increased significantly after 3 months (0.8 ± 0.63 and 1.9 ± 0.88, p < 0.05).

Conclusions

The self-etch adhesive exhibited better long-term sealing ability in dentin when compared to that of the etch-and-rinse adhesive. The greater hybrid layer thickness and dimensions of resin tags did not guarantee reliable, long-lasting sealing in the bonding area.

Microleakage and Resin-to-Dentin Interface Morphology of Pre-Etching versus Self-Etching Adhesive Systems

The purpose of this study was to compare the microleakage and tissue-adhesive interface morphology from Class V restorations using different systems of dentin adhesives. Class V cavities were prepared on buccal surfaces of 27 extracted caries-free molars and premolars. Teeth were randomly assigned to one of three groups: (1) Prime & Bond NT, a 5^th generation system using an initial step of total etch followed by a second step of application of a self bonding primer (2) Clearfil SE Bond, a 5^th generation adhesive system employing two separate steps of self-etch priming and subsequent bonding (3) One-up Bond F, a 6^th generation one step self-etching, self-priming and self-bonding adhesive. Microleakage and interface morphology of teeth restored with these adhesives and a composite resin were evaluated. Kruskal-Wallis Test (p = 0.05) was used to analyze the results. SEM analysis was used to relate interface morphology to microleakage. The mean and (SD) values of microleakage were: Prime and Bond NT: 0.15 (0.33), Clearfil SE Bond: 0.06 (0.17) and One-up Bond F: 2.96 (0.63). The mean microleakage for One-up Bond was significantly higher than for the other groups (p<0.05). Protruding tags in dentin channels were observed in Prime and Bond and Clearfil systems, but not in One-up Bond. The single step adhesive system, although more convenient for the clinician, uses a low viscosity formulation difficult to keep in place on cavity walls. It also tends to be too aggressive and hydrophilic to create an impermeable hybridized tissue-adhesive interfacial layer resistant to microleakage. Two-step adhesive systems, on the other hand, were retained on all segments of the cavosurface during application, and formed a hybridized interfacial layer resistant to microleakage.

Retention of a resin-modified glass ionomer adhesive in non-carious cervical lesions. A 6-year follow-up

OBJECTIVES

The purpose of this study was to evaluate the clinical retention of a new resin-modified glass ionomer cement based adhesive combined with a hybrid resin composite or a poly-acid modified resin composite in non-carious cervical lesions during a 6-year period.

METHODS

The resin-modified glass ionomer adhesive (Fuji Bond LC), was placed in 73 cervical lesions, 36 with a universal hybrid resin composite (Tetric Ceram) and 37 with a poly-acid modified resin composite (Hytac). Fifty-one in lesions with sclerotic dentin and 22 in non-sclerotic ones. Of the sclerotic lesions 38 were slightly roughened with a diamond bur before conditioning. The restorations were evaluated with slightly modified USPHS criteria every six months during a 6-year period.

RESULTS

All except six restorations were evaluated during the 6 years. Twelve (17.9%) were lost, four Tetric Ceram (11.8%) and eight Hytac (24.2%) (p<0.05). Four were found in non-sclerotic lesions (20.0%) and eight in sclerotic lesions (17.0%). The differences between the sclerotic and non-sclerotic and the roughened and non-roughened lesions were not significant.

CONCLUSIONS

The resin-modified glass adhesive showed a superior clinical retention combined with the resin composite material, with an annual failure rate of 2%.

A three-year clinical evaluation of two-bottle versus one-bottle dentin adhesives

BACKGROUND

The authors conducted an in vivo investigation to compare the clinical performance of two commercial one-bottle adhesives and a two-bottle adhesive for restoration of noncarious cervical lesions (NCCLs).

METHOD

The patient pool consisted of 57 patients and 171 teeth (three teeth per patient), with one NCCL per tooth. Each patient received three resin-based composite restorations, each with a different adhesive: one tooth with a two-bottle, water-based adhesive as the control; another tooth with a one-bottle, ethanol-based adhesive; and a third tooth with a one-bottle, solvent-free adhesive. The authors assessed restorations in terms of retention, marginal integrity, margin discoloration and air sensitivity at baseline, six months, one year, two years and three years after initial placement.

RESULTS

The retention rates at 36 months were 88 percent for the first adhesive, 81 percent for the second adhesive and 90 percent for the third adhesive. No statistically significant differences in retention rates could be shown, with 86 percent of restorations retained overall. Measures of marginal integrity, marginal discoloration and sensitivity also had no statistically significant differences between the three adhesives (P > .05).

CONCLUSIONS

All three adhesives performed with acceptable outcomes after a 36-month period, with small differences between the one- and two-bottle systems and between the various solvents. Retention rate was moderately high and air sensitivity was markedly reduced; however, superficial marginal discoloration and marginal degradation was notable. Certain lesion, tooth and patient characteristics may predispose restorations to retention failure.

CLINICAL IMPLICATIONS

The type of solvent may not be a major factor in retention of Class V restorations in NCCLs. Both single-bottle adhesives and conventional two-bottle adhesives performed acceptably.

Effect of dentine conditioners on the bonding efficacy of one-bottle adhesives

The bonding efficacy of four one-bottle adhesives (OptiBond Solo Plus, Gluma Comfort Bond, One Step and Prime & Bond NT) and a multi-step adhesive (Clearfil Photo Bond) as a control was evaluated. The dentine cavity wall was conditioned with phosphoric acid or ethylenediaminetetraacetic acid (EDTA) and the marginal integrity was estimated by measuring the wall-to-wall contraction gap width between the composite and the dentine cavity surface. In the positive control group, the adhesive was applied following glyceryl methacrylate (GM) priming. The analyses were performed by Kruskal-Wallis and Mann-Whitney U-tests. One-bottle adhesives were clearly inferior to the multi-step bonding system in marginal integrity when dentine was conditioned with EDTA. The present findings also suggested that the marginal sealing ability of ethanol-based one-bottle systems was better than acetone-based one-bottle systems when dentine surfaces were conditioned with EDTA. Nevertheless, further investigations are needed on the function of fillers in one-bottle adhesives for the prevention of contraction gaps.

The influence of resin composite and bonded amalgam restorations on dentine permeability in Class II cavities in vitro

OBJECTIVES

This study was conducted to measure and compare dentine permeability reduction in Class II preparations, after restoration with resin composite or bonded amalgam, using either a multi-step or one-bottle dental adhesive system.

METHODS

An in vitro fluid transport model was used to measure initial dentine permeability in Class II cavities with an intact smear layer in crown segments from extracted human premolars. One week and 3 months after restoration with resin composite or bonded amalgam, using either multi-step or one-bottle dental adhesive system, the measurements were repeated and the reduction in permeability was calculated as a percentage of the initial values. The data were analyzed statistically using a one-way ANOVA and Least Significant Difference tests.

RESULTS

After 1 week the resin composite with one-bottle dental adhesive system provided the highest reduction in dentine permeability, whereas after 3 months the bonded amalgam caused the highest reduction. At both time intervals the resin composite with multi-step adhesive system provided the lowest reduction. (P=0.036 at 1 week, P=0.016 at 3 months). After 3-months storage in water a significant increase in dentine permeability reduction was found in the bonded amalgam group only (P=0.017). The reduction in dentine permeability provided by resin composite with one-bottle dental adhesive system and bonded amalgam in Class II cavities was similar at both time intervals. (P=0.182 at 1 week, P=0.750 at 3 months).

SIGNIFICANCE

The results of this study indicated that on the basis of reducing dentine permeability in vitro, resin composite restorations with the investigated one-bottle adhesive system was superior to its multi-step equivalent and bonded amalgam can also be preferred in Class II restorations.

Penetration of radiocalcium at the margins of resin and glass ionomer dentine bonding agents in primary and permanent teeth

OBJECTIVES

The purpose of this study was to compare the leakage of three resin dentine bonding agents (Prime and Bond, Scotchbond Multi-Purpose, Probond) and a glass ionomer dentine bonding agent (GC Fujibond LC), in cervical cavities prepared in primary and permanent molar teeth restored with a hybrid composite resin (Tetric).

METHODS

Cervical cavities without a bevel at the cavo-surface margins were prepared in the buccal and lingual surfaces of extracted primary and permanent molar teeth. After being restored, the teeth were stored for 1 week in a saline solution at 37 degrees C and then thermally cycled between 5 and 55 degrees C. Marginal leakage was determined subsequently using a radioactive isotope containing 45Ca and an autoradiographic technique.

RESULTS

The results revealed that there were no statistically significant differences in microleakage of the bond between permanent and primary teeth dentine and Fuji Bond LC and Probond dentine bonding agents. The difference between permanent and primary teeth groups for gingival values of the Prime and Bond 2.1 group U=22.5, p=0.0355 and the Scotchbond Multipurpose group U=24.0, p=0.0406 were statistically significant. There were no significant differences between the occlusal and gingival microleakage values in either primary or permanent teeth with Prime and Bond 2.1, Fuji Bond LC and Probond except the difference at Scotchbond Multipurpose in primary teeth. For primary teeth gingival margins, none of the bonding systems were significantly different from the control group.

CONCLUSIONS

These results indicate that although no statistically significant differences were found between test and control group values, the use of Fuji II LC in cervical cavities with cementum margins in primary teeth would provide the best resistance to microleakage among the test materials while the use of Scotchbond Multi-Purpose would provide the best resistance to microleakage in cervical cavities with cementum margins in permanent teeth.