Biomedical subjects

F F Tung

Publications and source records attributed to F F Tung.

8 recordsLinked to original sources

PubMed2001

A multifunctional, provisional, implant-retained fixed partial denture.

This article describes the modification of a procedure for fabricating a laboratory-processed, metal-reinforced, acrylic resin provisional restoration that becomes an implant-retained fixed partial denture. The modification involves the incorporation of patrix and matrix components into a cast metal framework. The prosthesis can be used as an alternative to a removable radiologic stent and surgical guide. It can function as a surgical guide during implant placement and help retract the buccal mucogingival flap during implant placement. The prosthesis also can be used as an aid in locating the implant during stage II surgery. Finally, the pontics can be converted into an implant-supported provisional restoration immediately after the implant prosthetic components are attached to the uncovered implants.

Adult↗

PubMed2000

Accurate procedure for simultaneous registration of gingival emergence profile and maximal intercuspal position for metal ceramic restorations.

This article describes a procedure that simultaneously registers maximal intercuspal position and gingival emergence profile. The materials used in this procedure are inexpensive, readily available, and easy to use. The clinician can inspect the framework, cast, and tissue profile before sending them to the laboratory. When this method is properly used, it allows better communication with the dental technician, saves chair time, and reduces the number of laboratory procedures as currently practiced.

Acrylic Resins↗

PubMed2000

Microleakage of a condensable resin composite: an in vitro investigation.

OBJECTIVE: The purpose of this investigation was to evaluate microleakage in Class II cavities restored with the condensable resin composite SureFil, placed with or without a liner and 1 of 2 different dentin bonding agents. METHOD AND MATERIALS: Extracted noncarious human teeth were randomly divided into 4 groups of 15 each and restored according to manufacturer's instructions: group 1, SureFil and Prime & Bond NT; group 2, SureFil and PQ1; group 3, SureFil, PermaFlow, and PQ1; group 4, Heliomolar and Syntac Single-Component (control). Specimens were stored in 37 degrees C water for 24 hours. All specimens were thermocycled between 5 degrees C and 55 degrees C for 500 cycles. Each specimen was immersed in 0.2% basic fuchsin dye for 24 hours and then sectioned longitudinally and horizontally. Dye penetration at enamel and cementum margins were viewed at x30 magnification by 2 independent, calibrated evaluators. Specimens exhibiting dye penetration > or = 0.1 mm beyond the cavosurface margin were considered to have leakage. RESULTS: Chi-square tests revealed no statistically significant differences in the presence of microleakage when all groups were analyzed together. However, 2 by 2 comparisons revealed that group 3 had significantly fewer specimens with microleakage than did group 1, 2, or 4. CONCLUSION: To limit microleakage, a flowable composite should be used as a liner when a condensable composite material is used.

Acid Etching, Dental↗

PubMed2000

Use of a compomer in Class V restoration: a microleakage study.

OBJECTIVE: The purpose of this investigation was to evaluate the microleakage of Class V lesions restored with a compomer material (Dyractflow) using 2 single-bottle bonding systems. METHOD AND MATERIALS: Sixty-four Class V cavity preparations were made on 32 sound, extracted human premolars, 1 preparation on the facial surface and 1 on the lingual surface. Teeth were then randomly divided into 2 groups. Group 1, which served as the control group, was restored as follows: group 1a, facial surface with PQ1 single-bottle bonding system plus TPH resin composite; group 1b, lingual surface with Prime & Bond NT single-bottle bonding system plus TPH. Group 2 was restored as follows: group 2a, facial surface with PQ1 plus Dyractflow compomer material; group 2b, lingual surface with Prime & Bond NT plus Dyractflow. After 24 hours of storage in water and subsequent thermocycling, each specimen was immersed in 0.2% basic fuchsin dye for 24 hours. The teeth were sectioned longitudinally and horizontally, and dye penetration at enamel and cementum margins was viewed at x30 magnification by 2 independently calibrated evaluators. Specimens were evaluated as either having leaked or not having leaked. RESULTS: No statistically significant differences in microleakage were noted between group 1 and group 2 specimens. CONCLUSION: Both single-bottle bonding systems, PQ1 and Prime & Bond NT, demonstrated equal effectiveness in reducing microleakage beneath compomer and composite restorations.

Bisphenol A-Glycidyl Methacrylate↗

PubMed1998

Macromolecular leakage beneath full cast crowns. Part III: The diffusion of lipopolysaccharide and dextran.

STATEMENT OF PROBLEM: Most microleakage studies have used low molecular weight dyes or isotopes rather than clinically relevant materials, such as lipopolysaccharides or cell wall materials, that have been shown to provoke inflammatory reactions in the dental pulp. PURPOSE: This study evaluated the leakage (diffusion) of lipopolysaccharide and dextran beneath cast gold crowns luted with 3 cements. MATERIALS AND METHODS: Thirty extracted molars were prepared for crowns. Ten crowns with access ports (facial or lingual) were cast in gold and luted with zinc phosphate, glass ionomer, and an adhesive resin cement onto their preparations. Teeth and crowns with filters inserted into the ports were immersed in a solution of labeled macromolecules (TRITC-LPS, FITC-dextran) and evaluated for leakage at 2 weeks, and 1, 2, 3, 4, 5, and 6 months. Filters were retrieved and analyzed with fluorescent microscopy. RESULTS: All filters retrieved from crowns luted with zinc phosphate, glass ionomer, and adhesive resin cements demonstrated no detectable leakage and were negative for both FITC-dextran and TRITC-lipopolysaccharide at all evaluation periods. CONCLUSION: Leakage of lipopolysaccharides and dextran did not occur during the period of this study. For the length of this investigation, zinc phosphate, Ketac-Cem, and C&B-Metabond were equally effective at preventing leakage of detectable molecular concentrations of lipopolysaccharide and dextran to the level of the access ports.

Crowns↗

PubMed1994

Acellular pertussis vaccines in infants: evaluation of single component and two-component products.

Two acellular pertussis vaccines, one containing only LPF toxoid (25 micrograms) and the other containing LPF toxoid (25 micrograms) and FHA (25 micrograms) and each combined with diphtheria and tetanus toxoids, were evaluated in two groups of 25 infants. A third group of 25 infants served as controls and received a DTP whole-cell pertussis vaccine. Infants given either acellular pertussis vaccine had significantly fewer local and systemic reactions than infants given whole-cell vaccine. Among the three vaccine groups, infants given the LPF vaccine (single component) had the highest concentration of antibody to LPF after three immunizations. Infants receiving the LPF/FHA vaccine (two-component) had the highest concentration of antibody to FHA after three immunizations. Infants vaccinated with the two-component vaccine had a significantly lower serological response to LPF than infants given the single component vaccine, as measured by either enzyme-linked immunosorbent assay or CHO cell assay. Further studies are necessary to determine why differences in immunogenicity of the two investigational vaccines occurred.

Antibodies, Bacterial↗

PubMedDate not supplied

In vitro microleakage study of a condensable and flowable composite resin.

The aim of this study was to evaluate the in vitro microleakage of a condensable composite resin recommended for Class II restorations with and without a flowable composite resin as a liner. There were statistically significant differences between all groups and between individual groups (p < 0.05). The results showed significantly less microleakage in teeth restored with flowable composite resin underneath a condensable composite resin.

Acid Etching, Dental↗

PubMedDate not supplied

The antimicrobial properties of a urea-based handwash lotion with triclosan.

The purpose of this study was to determine and compare the antimicrobial action of a urea-based handwash lotion with triclosan with a lipid-depleting detergent-based handwash product with 4% chlorhexidine gluconate. The zones of inhibition produced by the two handwash lotions and the one produced by the positive control were similar against all strains of bacteria tested, indicating that a urea-based handwash lotion with triclosan is as effective as a lipid-depleting handwash lotion in inhibiting bacterial activity.

Actinomyces viscosus↗