Biomedical subjects

Linlin Han

Publications and source records attributed to Linlin Han.

6 recordsLinked to original sources

PubMed2006

Evaluation of a new fluoride-releasing one-step adhesive.

In this study, a newly developed S-PRG (surface pre-reacted glass-ionomer) filler-containing one-step adhesive, called SI (SI-IB551, Prototype), was evaluated regarding its fluoride release behavior. As a result, fluoride ion distribution in the tooth structures and acid resistance of cavity margins were also evaluated. In addition, Absolute (a fluoride-releasing one-step adhesive; AB) was evaluated in comparison to G-Bond (a non-fluoride-releasing one-step adhesive; GB) which was used as a negative control. Concentration of fluoride released was measured using a fluoride ion selective electrode after immersion of each material in distilled water. Fluoride distribution in tooth-adhesive interfacial areas was examined with EPMA following cavity preparation in human premolars and having treated resin restorations with each material. To evaluate acid resistance, restored specimens were immersed in an acetic acid buffer (0.2 M, pH 4.5) for 12 hours and then the cavity margins were observed using scanning electron microscopy. Amounts of fluoride released from AB and SI were significantly greater than that from GB. Further, significant differences in fluoride release were detected between AB and SI. A layer of increased fluoride density was clearly detected at the enamel- and dentin-SI interfaces. In terms of acid resistance, an acid resistance zone was also formed adjacent to the tooth-adhesive interface of AB and SI specimens. However, in GB specimen, acid resistance zone was not observed. These findings suggested that one-step adhesives displayed a favorable fluoride release property, thereby contributing positively to inhibition of recurrent caries.

Acrylic Resins↗

PubMed2005

Enamel micro-cracks produced around restorations with flowable composites.

In this study, enamel micro-cracks produced around flowable composite restorations were observed using a stereomicroscope and a scanning confocal laser microscope (SCLM). The effects of polymerization shrinkage, mobility of composite and polishing period after filling on the incidence of marginal enamel micro-cracks were examined. Enamel micro-cracks were observed on all of the composite restorations when the restoration was polished immediately after filling. Enamel micro-cracks distributed approximately parallel to the cavity margin and located 0.01-0.3 mm from the restored cavity margin. The occurrence of enamel micro-cracks was higher in conventional hybrid composite restorations than in flowable composites, and when polished 15 minutes after filling (as compared to 24 hours after filling).

Analysis of Variance↗

PubMed2004

An ultrastructural analysis of the prototype single-step adhesive applied on enamel and dentin surfaces.

A new type of self-etching agent, the single-step adhesive, was developed. The purpose of this study was to investigate the difference in the ultrastructural features of enamel and dentin surfaces following application of the prototype single-step adhesive (EXM618, 3M, MN, USA). Extracted caries-free human premolars were used in this study. Occlusal enamels of teeth--to be used as cut surface specimens--were removed perpendicular to the long axis of the specimens. The mesial and distal surfaces of these teeth, on the other hand, were used as uncut surface specimens in the test. In addition, Mega Bond (Kuraray Medical Inc., Tokyo, Japan) and Xeno CFII Bond (Dentsply Sankin, Tokyo, Japan) were used as controls. After covering half of the tooth surfaces with nail varnish (for control), the other half of each surface was treated with one of the three test adhesives--EXM618, Mega Bond, or Xeno CFII Bond--according to the manufacturer's recommendations. Conditioned enamel and dentin surfaces (i.e., decalcified depth and rugged surface) were observed with a scanning confocal laser microscope (SCLM 1100, Olympus, Tokyo, Japan; henceforth abbreviated as SCLM). Based on the findings of this study, the prototype single-step adhesive EXM618 appears to be suitable for use in dental clinics.

Acid Etching, Dental↗

PubMed2003

EPMA observation between dentin and resin interfaces. Part 1. Comparison of wet and dry technique after short-term stored in water.

The study was to evaluate the marginal leakage of wet or dry dentin condition after restoration on short-term. In the study we used Photobond adhesive system and Single Bond adhesive system. The specimens were prepared from premolars. A class V cavity was prepared at the CEJ with a high-speed hand piece and #010 round diamond point. The cavity's walls and floors were etched with phosphoric acids of the test materials by wet and dry bonding techniques. The specimens were cross-sectioned longitudinally through the center of the cavities with a low speed diamond micro-cutter and polished with carbide paper (#600-1200) after storage in distilled water for 1 day, and silver nitrate staining. Specimens were viewed with EPMA for elemental distribution of calcium, nitrogen and silver on the resin-dentin interface. The uptake of silver particles was less in samples treated with the wet-bonding technique when compared with dry-bonding technique. This in vitro study showed that bonding technique is important in establishing a seal along the restoration margins to control marginal leakage.

Acid Etching, Dental↗

PubMed2002

Effect of fluoride mouth rinse on fluoride releasing and recharging from aesthetic dental materials.

This study evaluated fluoride-release and recharging with the fluoride mouth rinsing technique on fluoridated materials. Three fluoride containing materials and one non-fluoride containing composite resin were used for this study. Samples for each material consisted of 15 discs, 9 mm diameter with a thickness of 1 mm. Initial fluoride release was assessed over a 60-day period. After that, 15 discs for each material were divided into 3 groups: distilled water group, 450-ppm and 900-ppm mouth rinsing groups. Fluoride release increased in combination with fluoride mouth rinse, and fluoride was higher in the 900-ppm group than the 450-ppm group. Moreover, S-PRG or F-PRG fillers materials released fluoride in higher than fluoroaluminosilicate glass fillers materials. In addition fluoride release from control samples was not observed. Therefore, only fluoride release material takes up fluoride. The findings of the present investigation suggest that the rate of fluoride release was different for each material, because they contained different function fillers. The results showed the importance of the fluoride mouth rinsing technique for fluoride-releasing restorative materials for the prevention of secondary caries.

Adsorption↗

PubMed2002

A comparative study of fluoride-releasing adhesive resin materials.

One of the most important and exciting properties of recently introduced dental restorative materials is their ability to release fluoride ions, as this has several advantageous effects on tooth structures. They have been extensively used as fluoride-releasing filling and luting materials. Recently, fluoride-releasing adhesive resins and fluoride-releasing adhesive resin cement have been developed and introduced for clinical use. The purpose of this study was to evaluate the fluoride release from these adhesive resins and the fluoride uptake by both enamel and dentin, as well as the acid-resistance of these tooth structures. Based on our results, we conclude that fluoride-releasing adhesive resins and luting cements are useful for the prevention of initial or secondary caries, especially along the margins of restorations.

Cariostatic Agents↗