Bonding of self-adhesive (self-etching) root canal sealers to radicular dentin.

The latest generation of methacrylate resin-based sealers has eliminated the use of separate self-etching primers by incorporating acidic resin monomers in the sealers to render them self-adhesive to dentin. This study examined the adhesive strengths, interfacial ultrastructure, and tracer penetration of a nonetching (EndoREZ; Ultradent, South Jordan, UT) and two self-adhesive methacrylate resin-based sealers (MetaSEAL; Parkell, Farmington, NY, and RealSeal SE; SybronEndo, Orange, CA) when they were applied to radicular dentin following the manufacturers' recommended use of EDTA as the active final rinse. A modified push-out testing design was used to evaluate the dislodgement of core-free sealers. The mixed sealers were placed in dimensionally identical, artificially created canal spaces prepared in the coronal, middle, and apical thirds of radicular dentin. After setting, each sealer-filled cavity was subjected to compressive loading until failure. Additional specimens were prepared for transmission electron microscopy to examine the ultrastructure and nanoleakage within the sealer-radicular dentin interface. The two self-adhesive sealers MetaSEAL and RealSeal SE exhibited higher push-out strengths than the nonetching sealer EndoREZ when EDTA was used as the active final rinse. All three sealers showed a 1- to 1.5-microm thick zone of partially demineralized dentin, with the EDTA dentin demineralization effect masking the true self-etching potential of MetaSEAL and RealSeal SE. The true self-etching potential of self-adhesive sealers is a clinically important attribute that should be further investigated. Incomplete smear layer removal from the apical third of instrumented canal walls may jeopardize the performance of self-adhesive sealers should they fail to self-etch without the adjunctive use of calcium chelating irrigants.

The impact of dental devices on neurostimulators.

Spinal cord stimulation has been a therapeutic option for chronic pain for over 40 years. The neurostimulator (NS) is a device consisting of three primary components: an electrode array configured either as a paddle or wire; an implantable pulse generator (IPG) consisting of a minicomputer, a transceiver/antenna, an electrical generator, and a battery; and insulated wiring connecting the electrode to the IPG. The electrode array can be implanted into the epidural space overlying the dorsal spinal cord or along a peripheral nerve. The device generates pulsed electrical signals that stimulate the underlying dorsal columns of the spinal cord resulting in the perception of paresthesia by the patient. When overlapped with painful areas, the paresthesia can help decrease the patient's level of pain. The increased applications and indications for this technology enhance the likelihood that the NS patient will be seen in the dental practice. Therefore, the purpose of this study was to investigate whether electromagnetic interference of the NS occurred during the operation of the apex locator, the electric pulp tester (EPT), or the electrocautery unit. An NS was implanted into the epidural space of a human cadaver. The dental devices were used intraorally, and the implant's circuitry was tested after each trial. Two apex locators, two EPTs, and one electrocautery unit were tested. Seventy trials were used by each dental device on each tissue. Using the exact binomial method of determining confidence intervals, the probability of damage to the NS by any of the devices was negligible.