James A. Wallace

Effect of Propolis on Human Fibroblasts from the Pulp and Periodontal Ligament

Propolis, a flavonoid-rich product of honey comb, exhibits antibacterial and anti-inflammatory properties. In this study, we examined the tolerance of fibroblasts of the periodontal ligament (PDL) and dental pulp to propolis and compared with that of calcium hydroxide in vitro. Cells from human dental pulp and PDL were obtained from healthy third molars and subjected to various concentrations of propolis (0-20 mg/ml) and calcium hydroxide (0-250 mg/ml). The cell viability after propolis treatment was analyzed by crystal violet staining of the cells followed by spectrophotometric analysis. Data revealed that exposure of PDL cells or pulp fibroblasts to 4 mg/ml or lower concentrations of propolis resulted in >75% viability of cells. On the contrary, calcium hydroxide 0.4 mg/ml was cytotoxic and <25% of the cells were found to be viable. Further investigations may find propolis to be a possible alternative for an intracanal antimicrobial agent.

Pulse Oximetry as a Diagnostic Tool of Pulpal Vitality

The technology of pulse oximetry has allowed significant advances in the medical field yet its use in dentistry has been virtually unexplored. This study investigates the potential of the pulse oximeter to detect vascular integrity within the human tooth. Forty-nine young adults were evaluated for the vitality of their maxillary central incisors utilizing thermal, electrical, and oximetric techniques. The pulse oximeter was found to indicate a pulse rate and oxygen saturation reading for the vital teeth and no readings for the teeth previously endodontically treated. The accuracy of this diagnostic method supports the need for additional study in the use of the pulse oximeter to interpret the pathological processes of the pulp.

Middle Mesial Canal of the Mandibular First Molar: A Case Report and Literature Review

With the advent of magnification, either by loupes or microscope, the astute clinician must be aware of recent literature that states that the mandibular first molar has a 1-15% chance of a fifth canal. This is a case report accompanied by a review of the literature that shows the unusual anatomy of the mandibular first molar.

Transantral endodontic surgery

A case is presented in which periradicular maxillary molar surgery was performed with the transantral approach. Included is a discussion of the related anatomy, physiology, and pathology of the maxillary sinus.

Effect of iterative restoration on the detection of artificially induced vertical radicular fractures by Tuned Aperture Computed Tomography

OBJECTIVE The purpose of this study was to evaluate the effect of the number of iterative restorations (IR) on the diagnostic accuracy of Tuned Aperture Computed Tomography images (TACT) for detection of induced vertical/oblique root fractures in mandibular teeth. STUDY DESIGN Fractures were induced in 28 single-rooted, endodontically treated cadaver mandibular teeth while another 26 such teeth served as controls. TACT slices reconstructed by using 9 arbitrary projections (angular disparity of 9 degrees -20 degrees) were iteratively restored 1, 2, and 3 times. Eight observers scored their diagnoses by using a confidence rating scale. Ground truth was available from direct examination with transillumination, following extraction. RESULTS Mean areas under the representative ROC curves for the 3 operations were 0.96 (3 IRs), 0.87 (2 IRs), and 0.86 (1 IRs). Analysis of variance demonstrated significant differences between 3 and 1 to 2 IRs (P <.01), as well as between observers (P <.01). CONCLUSION Diagnostic accuracy of TACT for vertical/oblique root fracture detection improved after 3 IRs.

An In Vitro Comparison of Microleakage of Restorative Materials in the Pulp Chambers of Human Molar Teeth

Ninety-six human molars were accessed. After flattening of the occlusal surface and removal of the apical two-thirds of the roots, the remaining canal space was instrumented by conventional methods. The teeth were divided into six groups of 15 teeth with three positive and three negative controls. The six experimental groups were based on the material used to restore the pulp chamber and remaining canal space: 1, gutta-percha with sealer; 2, amalgam; 3, IRM; 4, light-cured posterior composite; 5, chemical-cured core paste; and 6, light-cured glass ionomer. After placement of the restorative material, the teeth were thermocycled and evaluated for microleakage using 2% methylene blue dye and incremental sectioning. The amalgam and glass ionomer groups showed significantly less leakage than the other materials. The composite, core paste, and IRM did not differ significantly from one another. The gutta-percha with sealer group showed significantly greater leakage than all other groups.

Dens invaginatus: Another use for the ultrasonic

Dens invaginatus is an anomaly which has numerous and complex forms. Whenever endodontic therapy involving such a tooth becomes necessary, the clinician must be aware of the various treatment modalities available to facilitate proper care. Presented in this case report is a maxillary lateral incisor having the anomaly dens invaginatus in which both surgical and nonsurgical treatment was required. The surgical phase was facilitated through the use of ultrasonic instrumentation.

Blood mercury levels with amalgam retroseals: A longitudinal study

A clinical study was performed to determine if placement of an amalgam retroseal resulted in elevated blood mercury levels. Ten subjects had blood drawn 7 days before and immediately before placement of an amalgam retroseal. Postoperative blood draws occurred at 7 and 30 days. Blood samples were analyzed for mercury content by Cold-Vapor Atomic Absorption Spectrophotometry. No statistically significant increase in blood mercury levels was detected at 7 and 30 days after placement of an amalgam retroseal as compared with preoperative levels (p = 0.97). Findings support the hypothesis that placement of an amalgam retroseal does not result in significant elevations of blood mercury levels.

The inhibitory activity of typified propolis against Enterococcus species.

Propolis, a natural bee product widely used for its antimicrobial activity, was tested against isolates of Enterococcus from humans, pig-tailed macaques, isolates of refractory endodontic treatment cases, and isolates from Lactobacillus-containing food supplements. Typification of the propolis was performed by high-performance liquid chromatography (HPLC) by which prenylated compounds, cinnamic acid derivatives, and fl avonoids were detected as the main constituents. Minimum inhibitory concentrations (MIC) were determined using the agar dilution method. All human and animal Enterococcus isolates demonstrated MIC values of 1600 μg/mL. Enterococcal species of human and animal origin were inhibited by propolis. Particularly, human isolates of E. faecium and E. faecalis of refractory endodontic treatment cases were susceptible to propolis of Brazilian origin

Healing of osseous maxillary sinus defects using guided tissue regeneration: An experimental study in rabbits

The healing capabilities of the maxillary sinus in rabbits with and without a collagen barrier membrane after bilateral critical size defects were investigated at 4 wk after surgery. One maxillary sinus had a collagen membrane barrier positioned over the surgical site, whereas the other maxillary sinus surgical site served as a control. A histological evaluation showed that the experimental (barrier) defect had more complete osseous healing when compared with the control (nonbarrier) maxillary sinus defect. From the analysis of the Students t test for paired samples and the Wilcoxonpaired signed-ranks test, the healing capabilites of the maxillary sinus with the collagen barrier membrane could be considered statistically significant. It seems that the placement of the collagen barrier membrane after maxillary sinus exposure could have a beneficial effect.