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Biomedical subjects

G D Mattison

Publications and source records attributed to G D Mattison.

17 recordsLinked to original sources
PubMed1991

Psychophysical measurement on pain perception after administration of a topical anesthetic.

Topical anesthetics are routinely used to reduce the discomfort that patients perceive during dental injections. The purpose of this investigation was to correlate the expectancy of pain and the effect of pretreatment instructions with the severity of pain perceived upon topical anesthetic use and dental injection. The treatment, topical placebo versus topical anesthetic, was administered in a double-blind manner. Following testing for expectations, the administration of instructions, and placement of the topical, the injection was given. The patients were then asked to rate their injection experience on a posttreatment questionnaire. The results of this investigation reinforce the importance of psychological variables in the mediation of pain perceived during dental procedures.

Administration, Topical↗
PubMed1991

An in vitro investigation of the apical seal produced by a new thermoplasticized gutta-percha obturation technique.

This investigation quantitatively analyzed apical leakage in teeth in which one of two new thermoplasticized gutta-percha obturating techniques were used. Apical leakage observed after use of the thermoplasticized techniques was compared to leakage found in teeth that had been obturated with conventional lateral condensation. Statistically significant differences (P less than 0.05) were found among the three groups. The lateral condensation group exhibited the least leakage, followed by the thermoplasticized group, and the thermoplasticized twist-off group exhibited the most apical leakage.

Cuspid↗
PubMed1990

Post preparation techniques and their effect on the apical seal.

It is accepted clinical procedure to extend post preparations to such a depth that 3 mm to 5 mm of gutta-percha remains at the apex of the tooth. Clinicians use numerous techniques to achieve this goal. This investigation quantitatively analyzed the effect of the method of gutta-percha removal on the apical seal and evaluated apical leakage in teeth with different levels of remaining gutta-percha. The methods evaluated included the GPX instrument, heated pluggers, and Gates-Glidden drills. Groups of 25 extracted teeth were prepared with each of the three methods leaving 3 mm or 5 mm of gutta-percha remaining apically. Spectrophotometry (optical density) was used to assess apical leakage. Significantly less leakage was observed with the heated plugger technique at the 3 mm and 5 mm levels when compared to the 3 mm and 5 mm levels in both the GPX and Gates-Glidden groups.

Analysis of Variance↗
PubMed1985

Endodontic considerations in the design of acid-etched anterior splints for patients with reduced periodontal support.

A modification of existing designs for resin-bonded retainers has been introduced. This new design is appropriate for the extracoronal splinting of anterior teeth with reduced periodontal support. The design of the splint will accommodate the increased risk of these teeth for endodontic failure. The versatility and advantages of this design have been presented and compared with other anterior splinting techniques. At present, there appears to be no clinically significant difference in the retentiveness of perforated and nonperforated etched metal retainers.

Acid Etching, Dental↗
PubMed1984

Effect of post preparation on the apical seal.

Apical leakage was analyzed quantitatively in extracted teeth with varied levels of remaining gutta-percha. The effect of the method of gutta-percha removal on the apical seal was also evaluated. Ninety teeth were prepared so that 30 teeth had 3 mm of gutta-percha, 30 teeth had 5 mm, and 30 teeth had 7 mm. An additional 75 teeth were divided into three groups of 25 each. A different method of gutta-percha removal was used for each group: hot instrument, mechanical rotary instrument, and chemical solvent. An electrochemical method was used to analyze apical microleakage. Measurements of leakage of each sample were obtained at 24-hour intervals for 30 days. The data suggest that the mechanical method is the most desirable for gutta-percha removal in post preparation. As the level of gutta-percha increased to 7 mm the degree of leakage decreased. At least 5 mm of gutta-percha is necessary for an adequate apical seal.

Crowns↗
PubMed1983

An endodontic-orthodontic technique for esthetic stabilization of externally resorbed teeth.

Previous studies reveal that external root resorption is often coincident with orthodontic therapy. Some investigators have reported that root resorption ceases when orthodontic therapy is terminated. However, this is not always the case. The purpose of this article is to present an 11-year history of an unusual case in which root-resorptive processes continued for 3 years after orthodontic treatment had been discontinued. The article also describes and discusses a combined endodontic-orthodontic approach to halt external root resorption and stabilize mobile maxillary anterior teeth. Calcium hydroxide therapy was instituted to inhibit inflammatory apical root resorption. A rectangular orthodontic wire was adapted and inserted intracoronally to splint the teeth esthetically. The advantages and disadvantages of this intracoronal splinting technique are compared with other extracoronal splinting methods. Examination of one-year recall radiographs suggested inhibition of the root resorption. Masticatory function was restored for the patient. Considerations for monitoring patients with this problem are discussed.

Adult↗
PubMed1983

Angulation loading effects on cast-gold endodontic posts: a photoelastic stress analysis.

Two-dimensional photoelastic stress analysis was used to investigate the effects of post diameter on stress distribution under angulated (26-degree) loads. Ten models were used; five for each diameter were tested. The models were placed in the straining frame of the polaroscope, and compressive forces of 30 and 60 pounds were applied to each of the models. Instantaneous photographs were made immediately after each load was applied. The fringe patterns were quantitated by determining the maximum fringe order in the test model. The results of this investigation suggest that (1) post diameter should be restricted with heavy anterior masticatory forces and (2) restricting post diameter conserves tooth structure and substantially reduces internal stresses within teeth that have cast-gold posts.

Crowns↗
PubMed1983

Electrochemical microleakage study of endodontic sealer/cements.

The sealing ability of five commonly used endodontic sealer/cements (Procosol, Diaket, Tubliseal, N2, and Nogenol), was studied by an electrochemical technique. Extracted teeth were prepared biomechanically and the root canals were sealed with one of the sealer/cements. Ten teeth were used for each material without an accompanying solid core. Microleakage was determined over a period of 30 days. The degree of leakage for the materials tested decreased in the following order: Diaket, Tubliseal, Nogenol, ProcoSol, N2. On the basis of this study and previously reported histopathologic studies of tissue compatibility, it appears that ProcoSol is the material of choice as an endodontic sealer/cement.

Dental Bonding↗
PubMed1982

Photoelastic stress analysis of cast-gold endodontic posts.

Two-dimensional photoelasticity was used to compare stresses generated upon loading of cast gold endodontic posts of two different diameters. Ten models were used, five for each diameter size tested. The models were constructed to simulate maxillary central incisors. Drill bits were used to prepare the root canal, and after root canal preparation was completed the post preparations were constructed using the Parapost system. The gold posts, made of type III gold, were cast using the Beauty Cast technique. A composite core was then placed on each of the posts to be tested. These models were positioned in a circular polariscope and vertical loads of 30 and 60 pounds were applied to each of the models, with the fringe patterns photographed immediately after each load was applied. The stresses were evaluated by determining the maximum fringe order in the simulated root and periodontium of the model. The results of this study suggest that (1) the diameter of a post with a core affects the magnitude of stress, (2) stress generally increases as post diameter increases, and (3) stress increases as the vertical load increases. It seems advisable to restrict the diameter of the post used in providing support for restorations, particularly when large occlusal for forces are exerted by the patient. The use of smaller diameter posts reduces the stresses exerted upon the dentin of the tooth and the tooth supporting structures, limits the amount of tooth material removed during preparation and, possibly, aids operative procedures by limiting the amount of tooth preparation.

Crowns↗