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Biomedical subjects

M E Connelly

Publications and source records attributed to M E Connelly.

At least 19 recordsLinked to original sources

A simplified approach to optimizing denture stability with lingualized occlusion.

Occlusal prematurities are destructive and destabilizing influences in complete dentures. Unless denture bases are adequately and evenly stabilized, it is virtually impossible to properly equilibrate the occlusion. One reason is that all artificial teeth in a denture unit are physically bound into a single denture base and literally act as a single tooth. Therefore, a single point of occlusal prematurity disrupts the entire denture occlusion and negatively affects the denture base stability and retention, preventing proper equilibration. This article describes a step-by-step approach using an intraoral central bearing point tracing device and lingualized occlusion to achieve an effective and simplified equilibration.

Bite Force↗

A universal boxing procedure: irreversible hydrocolloid and magnetic strip.

The goal of impression making is an accurate cast. The boxing procedure is a crucial step to preserve the details of the final impression especially of the vestibular area. This article describes an alternative boxing procedure that is compatible with all impression materials, is efficient, simple, inexpensive, and practicable.

Alginates↗

Comparison of bond strengths of three denture base resins to treated nickel-chromium-beryllium alloy.

PURPOSE: In-vitro bond strengths of 3 denture base resins (Trutone, Lucitone 199, and Triad) to a nickel-chromium-beryllium removable partial denture alloy (Ticonium) were tested with 3 surface pretreatments: sandblast, acid etch, and Rocatec (silica blasting), with or without primers (Dentsply, CR inlay cement, and Super Bond). MATERIAL AND METHODS: Lucitone 199 denture base resin bonded to the nonprimed sandblasted alloy specimen served as the control group. Alloy specimens were prepared, surface treated, and primed or not primed with primer. The treated specimens were then packed and processed with the denture base resin. Bonded specimens were stored in the distilled water at 37 degrees C for 24 hours, and then debonded in tension. The force at which the bond failed was noted, and bond strength was calculated in megapascals (MPa). Five replications for each condition (180 specimens total) were tested. RESULTS: Significant differences in bond strength were observed with primer, the most important factor, followed by pretreatment and denture base resin. Without primer for all 3 denture base resins, the Met-Etch and Rocatec treated group showed significantly higher bond strengths than the sandblasted groups. For Trutone denture base resin, nonprimed treated groups produced significantly higher bond strength than those for the other 2 denture base resin, nonprimed treated groups produced significantly higher bond strength than those for the other 2 denture base resins. The control group had zero bond strength. For Dentsply primer, the Rocatec treated group bonded to Lucitone 199 resin produced the highest bond strength value (14.8 +/- 1.8 MPa). For CR inlay cement, the Met-Etch and Rocatec treated groups for Lucitone denture base resin demonstrated the highest bond strength (19.3 +/- 4.8 MPa, and 19.3 +/- 1.8 MPa, respectively). For super Bond primer, the Met-Etch treated group for Trutone resin demonstrated the highest bond strength (19.8 +/- 6.2 MPa). CONCLUSIONS: Without primer, the control had the lowest bond strength (0 MPa), and the Trutone groups showed the highest bond strength (11.7 +/- 4.1 MPa). Met-Etch and Rocatec treated groups produced higher bond strengths than the sandblasted groups. The primed specimens demonstrated significantly higher bond strengths than nonprimed specimens, except for Trutone resin, for which primed specimens produced lower bond strengths than the nonprimed specimens.

Acid Etching, Dental↗

Comparison of bond strengths of denture base resins to nickel-chromium-beryllium removable partial denture alloy.

PURPOSE: In vitro bond strengths of a traditional denture base resin (Lucitone 199) and three adhesive denture base resins (Meta-Dent, Meta-Fast with liner, and Meta-Fast without liner) to treated nickel-chromium-beryllium (Ni-Cr-Be) partial denture alloy were tested with four alloy surface pretreatments (sandblast, Met-etch, Rocatec with silane, and Rocatec without silane), with or without primer (Dentsply). The Lucitone 199 resin bonded to the nonprimed sandblasted group was the control group. The hypothesis was the use of alloy pretreatments and/or primer does not improve the bond strength of denture base resins to sandblasted Ni-Cr-Be partial denture alloy. MATERIAL AND METHODS: Primed and nonprimed bonded specimens were prepared and finished, stored in 37 degrees C distilled water for 24 hours, then debonded in tension on a testing machine. The bond strength was calculated in megapascals (MPa). Five specimens were prepared and tested for each experimental condition, both with and without primer, for a total of 160 specimens. RESULTS: For three-way analysis of variance, the main effects of resins and treatment were statistically significant (p < 0.05), but the main effect of primer was not statistically significantly (p > 0.05). Without primer, the control group had the lowest bond strength (0 MPa). The three adhesive resin groups produced significantly higher bond strengths than the Lucitone resin groups. For the treated groups, nearly all sandblasted groups produced significantly lower bond strength than the other three treated groups. Meta-Dent to Met-etch treated group had the highest bond strength (23.9 MPa). With primer, the bond strengths of the Lucitone resin groups were significantly higher than the nonprimed groups, and the Lucitone resin-primed Rocatec treated group had the highest bond strength (14.8 MPa). For the three adhesive denture base resins, nearly all primed treated groups had significantly lower bond strengths than nonprimed groups. CONCLUSIONS: Without primer, the Lucitone resin-sandblast treated group (control) had the lowest bond strength (0 MPa). The Meta-Dent denture base resin with the Met-etch treated group had the highest bond strength (23.9 MPa). With primer, the Lucitone resin-primed Rocatec-silane treated group had the highest bond strength (14.8 MPa). For the adhesive denture base resins, nearly all bond strengths of the primed treated groups were significantly lower than the values of the nonprimed groups.

Acid Etching, Dental↗

Color stability of heat-activated and chemically activated fluid resin acrylics.

PURPOSE: Heat- and chemically activated acrylics processed by compression molding or fluid resin matrix techniques for fabrication of partial dentures were evaluated for color stability by reflection spectrophotometry after accelerated aging. MATERIALS AND METHODS: Samples of heat-activated (L199, PDON, SB) and chemically activated (PR, PVAR, SC) denture base acrylics were polymerized according to manufacturers' instructions. Samples were aged in an artificial aging chamber, and color was measured by CIE L*a*b* on a reflection spectrophotometer at baseline and after each of three aging cycles. RESULTS: At 450 kJ/m2, color changes of two chemically activated acrylics (PR and SC) were perceptible. PR became less red, whereas SC became darker and more yellow. The most color-stable acrylics were a heat-activated resin (SB) and one chemically activated acrylic (PVAR). CONCLUSIONS: The three heat-activated acrylics tested were more color-stable than two of the chemically activated acrylics, but one chemically activated acrylic (PVAR) recommended for a fluid resin matrix technique was color-stable.

Acrylic Resins↗

Determination of the existence of hinge movements of the temporomandibular joint during normal opening by Cine-MRI and computer digital addition.

PURPOSE: The purpose of the first phase of this two-part investigation was to determine if the opening motion of the mandible could be illustrated and described using a dynamic imaging method. The purpose of the second phase of the investigation was to determine if a center of rotation would be discovered. MATERIALS AND METHODS: Five volunteer subjects, 2 female and 3 male, whose temporomandibular joints had previously been determined to be asymptomatic, were examined by magnetic resonance imaging (MRI) during opening from a standardized position. The serial static images were reconstructed by the MRI's computer in "cine mode" to simulate dynamic motion, similar to a motion picture. For the second phase, each patient's series of static images were digitally added and manipulated by a computer graphics program to locate the center of hinge motion. RESULTS: After reviewing the animated images recorded on videotape, three independent dentist observers confirmed that the opening movement of the mandible was initially rotational, followed by translation within the glenoid fossa. A center of rotation was calculated to be in the anatomic center of the condylar head of all of the subjects in this study. CONCLUSIONS: This study showed that opening dynamics of the mandibular condyle could be studied by cine-MRI and that an opening hinge axis appears to be located in the anatomic center of the condylar head.

Biomechanical Phenomena↗

Relining dentures with metal bases.

Metal bases are common in both complete and removable partial dentures. Before the introduction of adhesive denture base material, relining of these bases was almost impossible. This article presents a case on the technique of relining a partial denture metal base, using a 4-META resin (Acrylic Solder). With this technique, metal base can be relined easily in the dental office.

Acrylic Resins↗

Titanium palate maxillary overdenture: a clinical report.

A clinical technique of using a cast titanium base in a maxillary overdenture for a patient with bruxism who has a history of repeated midline denture fractures is presented. The advantages of a metal palate and the favorable properties of titanium are discussed. This treatment provides the practitioner with a practical option for successfully treating difficult overdenture or conventional denture patients.

Aged↗

Trial base adapted with sealed temporary soft liner.

Autopolymerizing acrylic resin is combined with temporary soft reline material to make a record base. Rigid acrylic resin is formed over a wax spacer. The wax is removed and the loose-fitting base is relined on the master cast with soft reline material. The soft material is cured in a pressure pot and sealed with a mono-poly mixture. Visible light-curing material can be used instead of autopolymerizing acrylic resin.

Acrylic Resins↗

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.

Acrylic Resins↗

Treatment of open occlusions with onlay and overlay removable partial dentures.

The onlay removable partial denture has the primary purposes of restoration of esthetics and function through a conservative modification of the existing dentition. It is particularly applicable to open occlusion situations and in improving an uneven mandibular occlusal plane. Its use should be supplemented with specific instructions in proper cleansing and maintenance of underlying dentition and the prosthesis and with scheduled recall appointments.

Denture, Overlay↗

Custom prostheses used to support oral and maxillofacial surgery.

The number and complexity of oral and maxillofacial surgical procedures have increased markedly in the last 5 years. Various custom prostheses, both cast metal and acrylic resin, used to provide surgical fixation, stabilize skin grafts, and contour bone used to augment atrophic mandibles, were described. While these prostheses may appear complex, their fabrication in the dental laboratory involves standard techniques that are accomplished routinely. The complexity of the modality lies in the uniqueness of each patient's treatment plan, which requires a special level of understanding and cooperation by all members of the professional treatment team.

Adolescent↗