Biomedical subjects

J C Meiers

Publications and source records attributed to J C Meiers.

At least 19 recordsLinked to original sources

PubMed2001

Two-year composite/dentin bond stability.

PURPOSE: To examine the composite-to-dentin shear bond strengths over 2 yrs of three chemically different single bottle dentin adhesives: water-based Syntac Single Component (SSC); acetone-based Prime & Bond 2.1 (PB), and; ethanol-based and filled OptiBond Solo (OS). MATERIALS AND METHODS: Extracted human molars stored in 0.2% sodium azide were randomly assigned to each of three dentin bond groups for testing at 5 time periods (n=15). The crowns of the teeth were sectioned to expose occlusal dentin and the roots embedded in acrylic. The dentin was etched with 37% H3PO4 for 20 s, rinsed and dentin adhesives applied per manufacturers' instructions. A column of Z-100 composite was bonded to the treated dentin surface and light cured. Teeth were stored in distilled water at 37 degrees C and thermocycled for 1,000 cycles between 5 degrees C and 55 degrees C and tested in shear at 24 hrs (baseline), 6, 12, 18 and 24 months. Mean +/- SD shear bond strengths (SBS) were determined. RESULTS: ANOVA at a significance level of P< 0.05 revealed OS had significantly higher SBS at 6 and 12 months compared to baseline. PB had significantly higher SBS at 12 months compared to baseline. SSC had significantly higher SBV at 18 months compared to baseline. However, at 24 months the SBV for OS and SSC were significantly lower than at baseline. During all time periods, OS and PB had significantly higher SBS than SSC. CLINICAL SIGNIFICANCE: The long-term stability of resin-based composite to dentin bond strengths from single bond adhesives is questionable because after 2 yrs, bond strengths for two of the three tested dentin adhesives, OptiBond Solo and Syntac Single Component, were significantly lower than initial strengths.

Acid Etching, Dental↗

PubMed2001

Chairside prefabricated fiber-reinforced resin composite fixed partial dentures.

The introduction of pre-impregnated fiber-reinforced resin composites has provided the dental profession with the opportunity to fabricate and deliver adhesive, esthetic, and metal-free tooth replacements. Utilizing this technology, a prefabricated fiber-reinforced resin composite fixed partial denture prototype that allows rapid, cost-effective, and noninvasive fixed tooth replacement for single anterior teeth has been developed. Ideal situations for this type of service include: a fixed replacement following tooth loss from trauma; a fixed tooth replacement in medically compromised patients who cannot sit for extended periods of time or have local anesthesia; periodontally compromised abutments; a fixed space maintainer following orthodontic movement; and a fixed provisional during the post implant healing phase prior to loading. This article describes the framework construction and placement protocol for the prefabricated fiber-reinforced resin composite fixed partial denture.

Composite Resins↗

PubMed1999

Microleakage of composites and compomers in Class V restorations.

PURPOSE: To evaluate whether differences in material composition between various classes of resin-based composite and polyacid-modified resin-based composites (compomers) affect microleakage in Class V preparations. MATERIALS AND METHODS: Class V cavity preparations were made in the buccal/lingual surfaces of non-carious human molars with the occlusal margins in enamel and the gingival margins in dentin. Enamel margins were beveled, preparations etched, and a single bottle dentin bonding agent was applied. Preparations were restored with the following materials (n = 20): Heliomolar RO, Tetric Ceram, Tetric Flow, Flow-It, Flow-It LF, Compoglass F, and Compoglass Flow. Restorations were polished and teeth thermocycled, stained, and sectioned to evaluate both linear and penetrating microleakage. RESULTS: Within all groups there was significant increase (P < 0.05) in both linear and penetrating dentin microleakage when compared to enamel microleakage. Linear gingival microleakage results indicated that Compoglass Flow and Tetric Ceram had significantly less microleakage than Flow-It and Flow-It LF and that Compoglass Flow also had significantly less microleakage than Heliomolar RO. Heliomolar RO, Flow-It and Flow-It LF had significantly more penetrating dentin microleakage than Tetric Ceram. The fact that microleakage scores between groups of materials were not significantly different indicates that the ability to predict microleakage in Class V preparations among various classes of resin-based composite or compomer materials is a much more complex phenomenon than can be simply gathered from focusing on compositional differences alone.

Analysis of Variance↗

PubMed1998

Preimpregnated, fiber-reinforced prostheses. Part II. Direct applications: splints and fixed partial dentures.

This article is the second in a series that describes the development, physical properties, and clinical applications of fiber-reinforced composite materials. The development of fiber-reinforced composite technology has opened new avenues for fabricating direct tooth replacements and splints that are esthetic and simple in design and execution and have the potential for excellent durability. Splinting techniques for hypermobile dentitions or postorthodontic retention and the replacement of anterior and posterior teeth using a groove preparation, a denture tooth, and a fiber-reinforced composite framework will be described.

Composite Resins↗

PubMed1998

Preimpregnated, fiber-reinforced prostheses. Part I. Basic rationale and complete-coverage and intracoronal fixed partial denture designs.

This is the first of two articles describing the development and use of a continuous fiber-reinforced composite as a framework for the fabrication of fixed partial dentures and splints. The chemical composition and physical structure of the fiber-reinforced composite, along with the progression and development of a variety of fiber-reinforced composite materials, are discussed. Criteria for case selection, tooth preparation, and the clinical and laboratory procedures required for partial- or complete-coverage fixed partial denture fabrication and delivery are described.

Composite Resins↗

PubMed1997

The effect of dentin disinfectants on shear bond strength of resin-modified glass-ionomer materials.

The purpose of this study was to investigate the effect of dentinal disinfection with a 2% chlorhexidine or a 0.11% I2-KI/CuSO4 solution on the shear bond strength of three resin-modified glass-ionomer cements: Fuji II LC, Photac-Fil, and Vitremer. The occlusal surfaces of extracted human teeth were flattened to dentin. Specimens were randomly assigned to one of nine treatment groups (n = 12). For each glass-ionomer material, there was a control group and two treatment groups in which the dentin was treated with either a 2% chlorhexidine or a 0.11% I2-KI/CuSO4 solution before the dentin was treated with the recommended dentin conditioner prior to glass-ionomer bonding. Specimens were stored for 1 day in water, thermocycled, and tested in shear until failure. The chlorhexidine solution did not significantly affect the shear bond strengths of any of the cements, but the I2-KI/CuSO4 solution significantly lowered the bond strengths of Vitremer and Fuji II LC compared to the controls.

Chlorhexidine↗

PubMed1996

The bond strength of an adhesive resin luting cement to a variety of surface treatments of a high-palladium copper alloy.

PURPOSE: This study evaluated the tensile bond strength of a bisphenol glycidyl methacrylate (Bis-GMA) resin luting cement with four different surface treatments of a high Pd-Cu alloy. MATERIALS AND METHODS: For each surface treatment type (tin-plated, porcelain furnace oxide, air-abraded, and finished-only), 15 opposing half-dumbbell-shaped samples were cast and prepared in new Pd-Cu alloy. Samples were luted with a Bis-GMA resin luting cement at a film thickness of 80 microns using a custom alignment apparatus. Samples were stored in distilled water at 37 degrees C for 24 hours, thermocycled for 1,000 cycles, and then stored for 30 days in distilled water at 37 degrees C. Samples were then subjected to fracture in tension at a loading rate of 0.5 cm/min with the bond strengths calculated in megapascals (MPa). The fractured surfaces were examined using stereomicroscopy and scanning electron microscopy at various magnifications ranging from 5.5x to 500x to determine the type of bond failure (adhesive, cohesive, or mixed). RESULTS: Tensile bond strengths (mean +/- SD MPa) were: tin-plated, 30 +/- 15.7; porcelain furnace oxide, 23 +/-n 8.6; air-abraded, 8 +/- 8.1; and finished-only, 4 +/- 4.5. Statistical analysis of the tensile bond values using an ANCOVA and Tukey's multiple comparison test at a significance level of 0.05 indicated that there was no difference between the tin-plated and the furnace oxide groups, as well as between the air-abraded and the furnace oxide groups. However, there was significant difference between the tin-plated, the air-abraded, and the finished-only groups. The observed bond failures were predominantly mixed and cohesive in nature with only one adhesive failure. CONCLUSIONS: There was no significant difference in the tensile bond strengths between the tin-plated group or the porcelain furnace oxide surface group. This suggests that the less-technique-sensitive porcelain furnace oxide surface treatment offers an alternative for achieving high metal-resin bonds to a high Pd-Cu alloy.

Aluminum Oxide↗

PubMed1996

Surface roughness of glass-ceramic insert-composite restorations: assessing several polishing techniques.

The authors compared the effectiveness of seven polishing methods on glass-ceramic insert-composite restorations placed in plastic resin squares. The polishing methods used carbide dental finishing burs and diamond polishing paste, diamond abrasive finishing burs and diamond polishing paste, diamond abrasive finishing burs and composite resin finishing disks, diamond abrasive finishing burs and composite resin polishing points, diamond abrasive finishing burs only, diamond abrasive finishing burs followed by resin impregnated disks and an aluminum oxide polishing abrasive paste, and diamond abrasive finishing burs followed by diamond polishing paste. All systems achieved comparable smoothness except the carbide finishing burs, which damaged the insert-composite margin.

Acrylic Resins↗

PubMed1996

Effect of bulk insertion, prepolymerized resin composite balls, and beta-quartz inserts on microleakage of Class V resin composite restorations.

Polymerization shrinkage of resin composite at the margin can seriously decrease the longevity of the restoration. Three direct restorative techniques were evaluated for their effects on microleakage. Sixty Class V cavities were prepared in extracted human maxillary molar teeth. The cavities were restored with resin composite placed in one bulk increment, resin composite and a beta-quartz insert, or resin composite and a prepolymerized resin composite ball insert. After they were thermocycled and placed in 0.5% basic fuchsin for 24 hours, the specimens were sectioned and examined for microleakage. The restorations with a prepolymerized ball of resin composite exhibited significantly more microleakage than did restorations with a beta-quartz insert or restorations inserted in bulk.

Ceramics↗

PubMed1996

Effect of various types of contamination on microleakage between beta-quartz inserts and resin composite.

Beta-quartz glass-ceramic inserts are a recent attempt to counteract some of the detrimental mechanical properties of resin composites by decreasing polymerization shrinkage and increasing wear resistance. The purpose of this study was to evaluate how manipulation, contamination, and disinfection would affect the resin composite-beta-quartz insert interface, as determined by microleakage. Seven groups (n = 10) of Class V cavity preparations were placed in extracted human molar teeth and restored with a microfilled resin composite and beta-quartz insert. In six groups, contamination or disinfection--latex glove, bare finger, human saliva, 95% ethanol, or LpHse disinfectant--was applied to the insert prior to placement. Latex gloves, bare fingers, and saliva were found to have a detrimental effect on the insert-resin composite interface that could compromise the longevity of the restoration.

Ceramics↗

PubMed1996

Dimensional stability of two visible light-cured indirect inlay/onlay resin composite materials.

PURPOSE: To evaluate the dimensional stability over time of two visible light-cured indirect inlay/onlay resin composites. MATERIALS AND METHODS: Twenty working dies of a Class II preparation were constructed in type IV die stone from impressions of a master metal die. Working dies were randomly divided into two groups of 10 with Class II resin composite inlays fabricated using Brilliant Dentin (n = 10) and Triad inlay material (n = 10). Inlays were seated on the master metal die 1, 3 and 10 days after fabrication and resin replicas were made of the proximal gingival margin surface which were gold-sputtered and used for the measurement of gingival margin gap distances at four locations using an SEM micron measurement system. RESULTS: Triad inlays mean gingival margin gap measurement was significantly (P < 0.05) greater at 10 days versus 1 day. Brilliant Dentin inlays had no significant mean gingival margin gap measurement differences between any time periods. As a material, Triad inlays had significantly less gingival margin gap distances than the Brilliant Dentin inlays at all three time intervals.

Acrylic Resins↗

PubMed1996

Effect of disinfectants on the bond strength of composite to dentin.

PURPOSE: To investigate the effect of two cavity disinfectants, a 2% chlorhexidine (Bisco) and a 0.11% iodine/potassium-iodide/copper sulfate solution (ORA-5), on the shear bond strength of composite to dentin mediated by the dentin bonding agents (DBA), Syntac and Tenure. MATERIALS AND METHODS: The occlusal surfaces of 72 noncarious extracted human molar teeth were flattened to dentin using 500 grit sandpaper. They were randomly assigned (n = 12) to three groups within each DBA system: Bisco/Tenure, ORA-5/Tenure, Tenure, Bisco/Syntac, ORA-5/Syntac and Syntac. Dentin disinfectants were applied for 20 seconds and dried. DBA was applied following manufacturer's instructions. A hybrid resin composite (Tetric) was then bonded to all treated samples. The samples were thermocycled and tested in shear until failure. Fracture analysis was performed on dentin surfaces with both light and scanning electron microscopy. Shear bond strength data was analyzed using ANOVA, Student-Neuman-Keuls and Dunnett tests at P < 0.05. RESULTS: Shear bond values (Mean +/- SD, MPa) were: Syntac control 14.3 +/- 2.0, Bisco/Syntac 8.1 +/- 4.9 and ORA-5/Syntac 5.7 +/- 5.1; Tenure control 15.0 +/- 1.9, Bisco/Tenure 14.2 +/- 3.0 and ORA-5/Tenure 13.9 +/- 3.7. The only significant difference found between disinfectant treatment groups and the control groups was with Syntac. Fracture surface analysis revealed that with Tenure most failures were cohesive in resin but with Syntac, the disinfected samples displayed adhesive failures.

Analysis of Variance↗

PubMed1996

In vitro study of intraoral welding procedures for pure titanium.

This in vitro study investigated the temperature changes experienced during electric welding of titanium to determine if the welding heat presented a potential danger to pulpal vitality. Welds were applied to cast titanium simulations of a three-unit fixed partial denture containing two thermocouples measuring temperature changes. Mean maximal temperature changes were 127.4 degrees F near the weld and 68.6 F degrees at the axial wall. The mean times for the temperature to drop to within 10.0 degrees F of the starting temperature ranged from 84.1 to 133.7 seconds. The relatively low temperatures recorded in this study suggest that further investigation is warranted into the use of the welder intraorally.

Dental Casting Technique↗

PubMed1996

Microleakage of dentin bonding systems used with spherical and admixed amalgams.

PURPOSE: To evaluate the effectiveness of the dentin bonding systems (DBS) Tenure, Syntac, Amalgambond and All-Bond 2 using a resin-lined amalgam technique in preventing short-term microleakage in Class V cavity preparations restored with a spherical and an admixed alloy. MATERIALS AND METHODS: Class V cavity preparations were made on the mesial and distal surfaces of non-carious human mandibular molars with the occlusal margins in enamel and gingival margins in cementum. Prepared teeth were randomly assigned to 12 treatment groups (n = 10) consisting of each DBS, no liner and Copalite for both amalgam alloys. Samples were thermocycled, stained and sectioned to evaluate microleakage. RESULTS: The DBS-lined restorations had significantly less microleakage at both occlusal and gingival margins than the Copalite and unlined restorations. Among DBS, Syntac had significantly more microleakage with both alloys than either All-Bond 2 or Amalgambond. These results do not totally correlate to a previous study which used the same experimental design but included viscous liners in addition to the same DBS, indicating a potential difference between resin-lined versus resin-bonded amalgam techniques in preventing microleakage.

Analysis of Variance↗

PubMed1996

Effect of polymerization mode of a dual-cured resin cement on time-dependent shear bond strength to porcelain.

PURPOSE: To evaluate the shear bond strengths to porcelain and setting times of a dual-cured resin cement with light/chemical curing (dual) or chemical only curing versus time. MATERIALS AND METHODS: Variolink resin cement was bonded to specimens of etched, silanated porcelain. Groups of specimens were cured by dual cured or by chemical curing only. Shear bond strengths were recorded at 2, 3, 5, 60 minutes and 24 hours for dual cured and at 10, 20, 40, 50, 60 minutes and 24 hours for chemical-cured only after mixing. Kinetic-temperature profiles of dual and chemical curing modes of cement were calculated. RESULTS: Maximum bond strengths and time to attainment were 17.5 +/- 2.7 MPa at 60 minutes for chemical-cured and 26.1 +/- 2.3 MPa at 5 minutes for dual-cured. The peak in the kinetic-temperature setting profiles were 14.1 +/- 0.9 minutes for chemical curing and 52.2 +/- 5.2 seconds for dual curing. Dual curing provided significantly higher shear bond strengths versus chemical curing at both the 60-minute and 24-hour time periods.

Analysis of Variance↗

PubMed1995

Seating accuracy and fracture strength of vented and nonvented ceramic crowns luted with three cements.

Methods to facilitate the seating of artificial crowns can improve the gingival margins and ensure longevity. This study examined the effects of venting and different luting agents on the seating accuracy and compressive strength of Dicor ceramic crowns. Vented and unaltered anterior restorations were tested using zinc phosphate cement (ZnPO4), glass ionomer, and composite resin cement. Rexillium metal dies of a tooth preparation of a maxillary canine were provided and standardized crowns were fabricated. The artificial crowns were evaluated for adaptation of the finish line before and after cementation, then were compressively loaded to failure. Under the conditions of this study, neither the design of the artificial crown nor the luting agent had a significant effect on the compressive strength. Composite resinous cement appeared to enhance seating of the crown, whereas ZnPO4 cement inhibited seating.

Cementation↗

PubMed1995

Influence of saliva contamination and abrasion on resin to tin-plated alloy bond strengths.

This investigation studied the effects of abrasion and salivary contamination on the shear bond strength of a composite resin bonded to tin-plated gold alloy. Experimental groups (n = 15) consisted of: group 1, no surface treatment; group 2, enamel abraded; and group 3, saliva-contaminated. After surface stressing and bonding, groups were thermocycled before shear testing. Fractured interfaces were analyzed by use of light microscopy and SEM. Specimens in group 3 (12.2 +/- 2.5 MPa) had significantly lower bond strengths than group 1 (17.9 +/- 6.8 MPa). The shear bond strengths of resin bonded to tin-plated metal were significantly affected by salivary contamination but not by abrasion.

Acid Etching, Dental↗

PubMed1995

Measurement of hydrostatic pressures during simulated post cementation.

Tooth sensitivity and fracture after cementation of posts for endodontically treated teeth have been a problem. This investigation developed an in vitro method of measuring intraradicular hydrostatic pressures created during simulated post cementation. The testing apparatus consisted of a pressure transducer and brush recorder connected to precision milled post spaces in a Plexiglas block. Cast post and cores were fabricated and cemented with three different luting agents: resinous cement, glass ionomer cement, and zinc phosphate cement. Mean hydrostatic pressures (psi) recorded during post cementation were zinc phosphate cement, 22.67; resinous cement, 19.77; and glass ionomer cement, 17.66. Zinc phosphate cement created substantially greater hydrostatic pressures than either the resinous or glass ionomer cements. This in vitro system was capable of discriminating intraradicular hydrostatic pressures among different classes of luting agents.

Analysis of Variance↗