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Biomedical subjects

J L Lui

Publications and source records attributed to J L Lui.

At least 19 recordsLinked to original sources
PubMed2001

In vitro fertilisation of mouse oocytes reconstructed by transfer of metaphase II chromosomes results in live births.

The interaction between nucleus and cytoplasm can be explored through nuclear transfer. We describe here another tool to investigate this interaction: MII meiotic apparatus transfer (MAT) between mouse oocytes. In this study, the MII oocyte meiotic apparatus or spindle from C57BL/6 mice, a black strain, was transferred into an enucleated metaphase oocyte from Kunming mouse, a white strain. The results showed that the enucleation rate by treating oocytes with 3% sucrose was 100%, but the electrofusion efficiency was very low, with only 17.6% of reconstructed karyoplast-recipient cytoplasm pairs fused. When the fused oocytes were exposed to spermatozoa from C57BL/6 mice, 9 of 11 (82%) were fertilised. Eight reconstructed embryos at 1- to 4-cell stages were transferred into the oviducts of two synchronously pregnant Kunming strain fosters and one delivered two normal C57BL/6 offspring. This study indicates that MII meiotic apparatus or spindle sustains normal structure and function after micromanipulation and electrofusion. MAT provides a model for further research on the application of this technique to assisted human reproduction.

Animals↗
PubMed2001

A case report of reattachment of fractured root fragment and resin-composite reinforcement in a compromised endodontically treated root.

The composite reinforcement technique has been used clinically to salvage damaged root-filled teeth compromised by caries, trauma, developmental abnormalities, internal resorption and iatrogenic causes. This clinical case report describes the use of the technique to reattach a fractured fragment in a compromised endodontically treated root besides reinforcing it for continued function in the mouth. Factors of clinical importance related to this additional application; including reattachment of tooth fragments, post crown retention, coronal microleakage and fracture resistance and strength, are also briefly discussed.

Acid Etching, Dental↗
PubMed1999

Enhanced post crown retention in resin composite-reinforced, compromised, root-filled teeth: a case report.

The introduction of an intraradicular composite reinforcing technique, in conjunction with the reestablishment of matching post canal spaces, has allowed compromised, root-filled teeth to be restored with functional, esthetic post crowns. This clinical case report suggests that reconstituted post canals, in accurately adapting to passive, parallel-sided, matching, and well-fitting posts, can enhance the retention of post crowns. Other factors of clinical importance relating to the resin-reinforced technique are discussed, including fracture resistance, depth of polymerization, dentin adhesion, polymerization shrinkage, and coronal microleakage.

Adult↗
PubMed1994

Composite resin reinforcement of flared canals using light-transmitting plastic posts.

Composite resins have been advocated as a reinforcing build-up material for badly damaged endodontically treated teeth with flared canals. However, the control of an autocuring composite resin is difficult because it polymerizes rapidly within the root canal. While the light-curing composite resins are more user friendly, their polymerization can be a problem deep in the root canal. Light-transmitting plastic posts allow the transmission of light into the root canal and enable intraradicular composite resin reconstitution and reinforcement of weakened roots. At the same time, the light-transmitting plastic post forms an optimal post canal in the rehabilitated root and can accurately fit a matching retentive final post. These light-transmitting posts are a useful addition to the dental armamentarium.

Composite Resins↗
PubMed1992

Treatment of root fracture with accompanying resorption using cermet cement.

A method of treating an apical root fracture with accompanying resorption at the junction of the fracture fragments using glass-cermet cement is described. Endodontically, the material had previously been used for repair of lateral resorptive root defects and retrograde root fillings. Complete bone regeneration was observed three years post-operatively following treatment of the root fracture in the conventional manner. The various advantages of glass-cermet cement as a root filling material used in the technique described are discussed.

Adult↗
PubMed1992

Cermet reinforcement of a weakened endodontically treated root: a case report.

Many clinical applications have been recommended for glass-cermet cement because of its improved properties compared to the original glass-ionomer cements. It has also been accepted as a dentinal substitute that can strengthen teeth. In this paper, an additional clinical application for glass-cermet cement, the reinforcement of weakened endodontically treated roots, is suggested. This technique is in keeping with the trends of tooth conservation and the use of an adhesive restorative material in the restoration of severely damaged teeth by a conservative approach.

Cermet Cements↗
PubMed1988

Anchor-retained bridge: a conservative approach to tooth replacement.

The replacement of missing teeth by means of the recently-introduced anchorage system is described. The indications, contra-indications, advantages and disadvantages of the anchor-retained bridge are also discussed. This bridge should be an addition to the repertoire of the restorative dentist as it has a definite place in fixed prosthodontic work in carefully selected cases.

Denture Design↗
PubMed1987

Margin quality and microleakage of Class II composite resin restorations.

Margin quality and isotope microleakage analyses of Class II restorations placed in extracted human molars were compared using various composite resins and placement techniques. At occlusal margins, the traditional (experimental) composite resin restoration placed by the incremental technique showed less microleakage than did the traditional (commercial) [corrected] composite resin restoration placed by the bulk technique. In each group, the occlusal and proximal adaptations had significantly higher "excellent margin" than did the cervical adaptation. Thus, the marginal adaptation at the cervical aspect of conventional Class II composite resin restorations may present a problem with respect to microleakage.

Calcium Radioisotopes↗
PubMed1987

Treatment of discoloured anterior teeth using a simple veneering technique.

Discoloration of anterior teeth presents the restorative dentist with a complex aesthetic problem. Various methods are available for the management of discoloured anterior teeth. A simple one visit veneering technique using new improved composite resin materials and opaquing agents is described. Even though the technique provides interim treatment only, it has its advantages and definite clinical applications. The aesthetic result obtained is dramatic as the various shades available allow mixing and characterisation and even patient approval before polymerizing using a light curing system. The development of opaquing agents has allowed even the most severely discoloured anterior teeth to be adequately masked so that the underlying discoloration will not show through the translucent composite resin veneers.

Dental Veneers↗
PubMed1982

The surface finish of the new microfill restorative materials. A scanning electron microscope study.

Surface smoothness is an important requirement for restorative materials. Recently, restorative materials claimed to be inherently smooth in surface characteristics have been developed. Matrix-formed and finished surfaces of five new microfill restorative materials were compared with two composite resins, an acrylic resin and a silicate cement by means of scanning electron microscopy. The results of this investigation indicated that the matrix-formed surfaces of all the restorative materials studied were not altogether perfect. Polishing using sandpaper and cuttlefish discs produced a very smooth surface finish in the new microfill restorative materials, Estic microfill, Estilux microfill, Isopast, Isolux and Silar which was comparable to that of the acrylic resin, Sevriton. The composite resins, Adaptic and Estilux exhibited the worst surface finish and the silicate cement, Bio-trey was intermediate. Finishing, using other finer polishing devices on four of the materials produced a further improvement in the surface finish.

Acrylic Resins↗