Assisted retention of a hearing device in an implant-retained auricular prosthesis.

The use of bone-anchored hearing aids is not possible for all patients who wear an implant-retained auricular prosthesis. For some patients, the external ear canal cannot be occluded with a conventional hearing device. Currently manufactured hearing aids may not readily fit the contours of an implant-retained auricular prosthesis. This article describes a technique that allows a modular hearing aid device to be inserted into a custom "sleeve." With this device, the patient can take advantage of binaural cues.

Load-bearing behavior of a simulated craniofacial structure fabricated from a hydroxyapatite cement and bioresorbable fiber-mesh.

Calcium phosphate cements (CPC) have proven successful in the repair of small, non-stress bearing skeletal defects. These cements do not have sufficient tensile strength or fracture toughness to allow their use in stress-bearing applications. It was hypothesized that a bioresorbable fiber mesh would improve the load-bearing behavior of shell structures fabricated of CPC. This study used a biaxial flexure fixture to compare the work-to-fracture values of discs made of: (1) CPC; (2) CPC reinforced with a bioresorbable two-dimensionally oriented poly(glactin) fiber-mesh; and (3) poly(methyl methacrylate) (PMMA) that were immersed in a serum-like solution for 0-28 days. CPC-mesh and PMMA discs were indistinguishable at 0, 1 and 7 days, based on work-to-fracture data. CPC and CPC-mesh discs were indistinguishable at day 28, because of fiber hydrolysis. The knitted fiber-mesh was effective in improving load-bearing behavior of a calcium phosphate cement for potential structural repair of bone defects.

The management of endodontically treated teeth using a Computer-Aided Design and Computer-Assisted Manufacturing/Computer-Aided Design and Computer-Integrated Manufacturing system.

This article introduces a new approach for restoring endodontically treated posterior teeth. Significantly reduced natural tooth structure often remains not only because of previous restorative measures but also because of endodontic procedures. Cast restorations for these teeth are almost universally recommended. The exception to this is the rare instance in which only conservative endodontic access openings exist in teeth presenting with no former existing restorations. Typically, multiple clinical appointments are required to complete the final cast restoration. This article presents Computer-Aided Design and Computer-Assisted Manufacturing/Computer-Aided Design and Computer-Integrated Manufacturing applications for restorative dentistry that provide the necessary care in an expeditious manner.

Dental management of neonates requiring prolonged oral intubation.

An orotracheal route is frequently the preferred method of intubation for premature infants. Nasal intubation may contribute to airway obstruction and possible hypoxia, further contributing to labored breathing. Additional complications include occlusion of the nasal aperture during a crucial period of development, nasal infections, and hypertrophy of the nasal lining. Oral mucosa is less susceptible to damage than nasal mucosa; however, orotracheal tubes must be stabilized against displacement from tongue and jaw movements to prevent discomfort and subsequent tissue trauma. Problems associated with rehabilitation of very-low-birth-weight neonates and other infants requiring long-term oral intubation include palatal grooving, acquired cleft palate, and damage to the primary dentition. Various intraoral aids have been used to reduce pressure application from intubation and feeding tubes on the palatal tissues. References to these procedures have yet to be reported in the prosthodontic literature. This article presents a rational for design and construction of an intraoral device which protects the palatal tissues and stabilizes the orotracheal tube.

Modifications in the design and fabrication of mandibular osseointegrated fixed prostheses frameworks.

This article presents the advantages of design modifications and fabrication techniques for mandibular osseointegrated fixed prostheses. These design features provide definite mechanical advantages and access for oral hygiene maintenance. A review of implant surface properties is presented that affect bacterial plaque and food debris adherence. The suggested design involves a lingual contour of the cast alloy suprastructure to yield an environment for reduced plaque and debris accumulation. The right angle cross-section ensures strength and increased stress distribution in structurally compromised areas when compared with conventional implant framework designs.

Biomechanical and esthetic considerations for maxillary anterior overdenture abutment selection.

Maxillary canine teeth traditionally have been selected as overdenture abutments. Undesirable aspects associated with the use of maxillary canines as overdenture abutments are described. The use of maxillary lateral incisors as overdenture abutments offers vertical support to the prosthesis, favorable stress distribution, improved esthetics, and preservation of the premaxilla.

Effects of laboratory disinfecting agents on color stability of denture acrylic resins.

This study determined the effects of chemical disinfecting agents on denture acrylic resins. Tested resins included the products CH Lucitone, Triad VLC, and Truliner. The disinfecting agents were sodium hypochlorite, Exspor, Cidex, and Wescodyne-D. Acrylic resin samples were placed in the various disinfecting agents and then evaluated for color changes at time intervals ranging from 15 minutes to 72 hours. No observable color change of any acrylic resin was seen before 2 hours. Both 1% sodium hypochlorite and 2% Cidex disinfectants produced the least discoloration of the acrylic resins, and Wescodyne-D disinfectant produced the most acrylic resin discoloration. Truliner resin discolored more than Triad VLC resin, and both underwent more color change than CH Lucitone resin. If manufacturers' recommended disinfecting times are followed, clinical and laboratory disinfection of acrylic resin dentures should cause no observable color change.

Nocturnal electromyographic evaluation of masseter muscle activity in the complete denture patient.

Nocturnal oral activity was evaluated in 12 complete denture wearers by means of EMG measurements of the masseter muscle. Patients who had worn dentures for at least 6 months were selected. EMG levels were compared when subjects slept with and without the dentures in the mouth. Three subjects appeared to have reduced EMG values when sleeping with the dentures. However, no overall group trends or significant differences were obtained. High variability in nightly EMG values could not be explained by a post hoc analysis of patient oral symptoms or denture characteristics. Efforts should be directed at improved methodology to study the specific mechanism of the effect of denture wearing on nocturnal muscle activity levels. Additional knowledge is needed on the occurrence and effects of parafunctional habits in the edentulous patients.

The cast round RPA clasp.

The incorporation of a cast round clasp into the RPA design has been presented. When properly used, the cast round clasp eliminates the need for blockout of the facial aspect of the terminal abutment normally required with the half-round clasp. This technique includes surveying the refractory cast, which ensures optimal placement of the round clasp in relation to the height of contour.

Aluminum-based temporary removable partial dentures.

The fabrication of an aluminum-based temporary removable partial denture has been presented. The advantages of this type of prosthesis include compatibility with oral tissues, accuracy of fit, decreased bulk, and improved thermal conductivity.

Modified finish line in distal extension maxillary removable partial dentures.

Finish line modifications provide adjustability and facilitate relining in the hamular notch as changes in tissue contour dictate. Time problems and inconvenience of dealing with a metal-acrylic resin junction, are eliminated while necessary postinsertion procedures are accomplished. In addition, the acrylic resin denture base is retained securely to the metal framework for the entire length of the external finish line.

Laboratory pitfalls that contribute to embrasure clasp failure.

Use of an embrasure clasp demands attention to proper clinical preparation and to laboratory procedures as well. This article outlined pitfalls that occur in the laboratory, and appropriate solutions were offered.

Nocturnal muscle activity in the edentulous patient with and without dentures.

Nocturnal oral activity was evaluated in four complete denture wearers by means of masseter muscle EMG measurements. Patients who had worn dentures that were judged satisfactory for at least a 1-year period were selected. EMG levels were compared when subjects slept with and without the dentures in the mouth. All subjects showed a decrease in the integrated muscle activity while wearing the dentures. Additional studies need to be directed at understanding the mechanism of the effect of denture wearing on nocturnal muscle activity.

Evaluation of the accuracy of a new plasterless plane line articulator.

The accuracy of a technique that allows rapid and repeated cast mountings without the aid of gypsum products was determined. The results indicate that errors of dimensional change inherent in plaster or dental stone mountings are avoided with use of this plasterless mounting procedure. In view of the findings, this articulator is recommended as a reliable laboratory instrument.