Radiographic interpretation of experimental lesions in radicular tooth structure of human maxillary anterior teeth.

External resorption is often first detected radiographically. Early detection can lead to timely intervention and improvement of treatment outcome. The purpose of this study was to determine the minimal radicular defect size in maxillary anterior teeth that is radiographically detectable.

Comparative study of the variability of 0.06 tapered rotary endodontic files to current taper standards.

This study compared the taper variation among Profile, Guidance, and EndoSequence 0.06 tapered rotary files to current standards. Fifteen files of sizes 35, 40, and 45 from each manufacturer were evaluated for a total of 135 files.

An in vitro evaluation of the growth of human periodontal ligament fibroblasts after exposure to a methacrylate-based endodontic sealer.

The cytotoxicity of Epiphany root canal sealer at various concentrations from 25-800 microg/mL on human periodontal ligament (HPDL) fibroblasts was evaluated at 1, 3, and 7 days. Controls included untreated cells and cells treated with the vehicle for Epiphany suspension. Fibroblast viability was assessed by 2 methods, crystal violet staining in 24-well plates and the fluorescence-based CyQUANT Cell Proliferation Assay in 96-well plates.

Unevenness of the apical constriction in human maxillary central incisors.

This study examined the incisoapical extent of the apical constriction in 45 human maxillary central incisors. The null hypothesis was that the apical constriction is a flat ring. Our working hypothesis was that the constriction is actually uneven or "skewed" as it traces a path around the circumference of the canal.

Effect of endodontic irrigants on the shear bond strength of epiphany sealer to dentin.

This study examined the effects of commonly employed endodontic irrigants on Epiphany-dentin bond strengths. Smear layers were created on dentin discs obtained from human third molars. Five groups of 10 discs each were treated with one of the following: (a) water; (b) 2% chlorhexidine; (c) 6% sodium hypochlorite (NaOCl); (d) 6% NaOCl followed by EDTA and water; or (e) 1.

Net expansion of dried demineralized dentin matrix produced by monomer/alcohol saturation and solvent evaporation.

The purpose of this work was to determine if nonaqueous methacrylate monomer/alcohol mixtures could expand dried collapsed demineralized dentin matrix. Thin disks (ca. 200 microm) of human dentin were demineralized and placed in wells beneath contact probes of linear variable differential transformers.

A comparison between in vivo radiographic working length determination and measurement after extraction.

The purpose of this study was to compare the difference between the in vivo working length established by viewing a periapical radiograph and the in vitro measurement from the file tip to the apical foramen of the extracted tooth. Twenty-six canals from teeth that had been treatment planned for extraction were accessed under rubber dam isolation. The coronal portion of each canal was flared using Gates Glidden drills, and a K-type file was inserted down the canal until an electronic apex locator indicated that the file had reached the apex.

Infiltration/evaporation-induced shrinkage of demineralized dentin by solvated model adhesives.

During dentin bonding, solvated adhesive comonomers are applied to water-saturated decalcified dentin matrices. When alcohol-solvated hydrophilic or hydrophobic methacrylate monomers are applied, they chemically remove water and cause matrix shrinkage during comonomer infiltration. Evaporation of solvent induces further shrinkage.

A comparative photoelastic stress analysis of internal root stresses between RC Prep and saline when applied to the Profile/GT rotary instrumentation system.

The purpose of this study was to measure and compare the amount of stress produced by GT ProFile (GT) and ProFile (PF) rotary files lubricated with either RC Prep (RCP) or saline (S) on the walls of prepared simulated canals. Twenty-four 10-mm long canals with a 10 mm radius of curvature were prepared in PL-2 photoelastic acrylic blocks which were lubricated with either RCP or S. The files were inserted into a Nouvag handpiece mounted to an Instron 4502 universal testing machine and lowered into the canal at a rate of 60 mm/min and a rotational speed of 300 RPM.

An in vitro evaluation of the antibacterial efficacy of chlorine dioxide on E. faecalis in bovine incisors.

This study investigated the ability of chlorine dioxide to eliminate Enterococcus faecalis from dentinal tubules of bovine incisors. Thirty-seven extracted bovine incisor roots were sectioned into seventy-four 5 mm disks. Standardized lumens were filled with either sterile Brain Heart Infusion Broth (contamination controls, n = 10) or BHI containing E.

An in vitro evaluation of the cytotoxicity of various endodontic irrigants on human gingival fibroblasts.

The purpose of this study was to measure the cytotoxicity of six endodontic irrigants on cultured gingival fibroblasts using the CyQuant assay. Human gingival fibroblasts were grown in Dulbecco's Modified Eagle Medium (DMEM) containing 10% fetal bovine serum at 37 degrees C and 5% CO(2). At confluence, cells were split, plated in 96-well plates and incubated for 24-h to allow attachment.

A comparison of the in vitro retentive strength of glass-ionomer cement, zinc-phosphate cement, and mineral trioxide aggregate for the retention of prefabricated posts in bovine incisors.

The purpose of this study was to compare the retentive strength of zinc-phosphate cement, glass-ionomer cement, and mineral trioxide aggregate (MTA) cement in the retention of prefabricated posts. The root canals of 60 bovine incisors were prepared and obturated with warm gutta-percha. Post space was prepared, the smear layer removed, and posts were luted with zinc-phosphate cement, glass-ionomer cement, or MTA.

Antibacterial efficacy of calcium hydroxide, iodine potassium iodide, betadine, and betadine scrub with and without surfactant against E faecalis in vitro.

Objective: This study investigated the ability of endodontic irrigants and medicaments to eliminate Enterococcus faecalis from infected dentinal tubules, and whether their antimicrobial action was enhanced by surfactant.

Study Design: For the study, 5-mm dentin disks were sectioned from bovine incisor roots and infected with E faecalis. Lumens were instrumented, and 1 of 7 medicaments (10% Ca(OH) 2, Betadine, or IKI, each with or without surfactant, or Betadine Scrub) was used to flush and fill each lumen.

Sealing ability of One-Up Bond and MTA with and without a secondary seal as furcation perforation repair materials.

This study investigated the ability of One-Up Bond alone and mineral trioxide aggregate (MTA), with and without a secondary seal of One-Up Bond or SuperEBA to seal saucer-shaped perforation defects in human molars. Cusps were removed, roots were amputated, and endodontic therapy completed on 40 extracted teeth. A cylindrical hole was made in each tooth from the furcation area to the chamber, into which a section of steel tubing was cemented.

Antibacterial efficacy of calcium hydroxide and chlorhexidine gluconate irrigants at 37 degrees C and 46 degrees C.

This study investigated the ability of two endodontic irrigants to eliminate Enterococcus faecalis from dentinal tubules, and whether their antimicrobial action was enhanced by heat. The lumens of disks prepared from extracted bovine roots were infected with E. faecalis and incubated for 72 h.