ABSTRACT
The purpose of this study was to compare the effects of amalgam restorations with and without overhangs on alveolar bone loss via digitized radiographs for subjects of varying ages and overhang widths. The first phase of this study compared the alveolar bone loss among teeth with clinically acceptable two-surface amalgam restorations with a control surface on the same tooth. The second phase was similar to the first phase with the exception that it compared defective amalgam restorations (those containing amalgam overhanging approximal margins) with the control surface on the same tooth. The collected data showed a significant loss of alveolar bone as a result of amalgam overhang presence (P < 0.02). However, overhang width and patient age did not affect the significance of the detrimental effects of the amalgam overhangs. Overall alveolar bone height was seen to decrease with patient age, independent of amalgam restorations. Digital radiography was seen to be an accurate method for evaluating alveolar bone height changes due to the local environment created by overhanging amalgam margins.
Subject(s)
Alveolar Bone Loss/etiology , Dental Amalgam , Dental Restoration, Permanent/adverse effects , Adult , Age Factors , Aged , Alveolar Bone Loss/diagnostic imaging , Alveolar Process/diagnostic imaging , Dental Restoration Failure , Dental Restoration, Permanent/statistics & numerical data , Humans , Middle Aged , Radiography, Dental, Digital/methods , Regression Analysis , Retrospective StudiesABSTRACT
Natural teeth are an invaluable teaching tool for preclinical instruction in operative dentistry and endodontic techniques. Cavity preparation in teeth containing amalgam restorations is a realistic simulation of an often experienced clinical situation. As various pathogens are contained in saliva, teeth must be disinfected before use by students. The purpose of this study is to indirectly evaluate whether mercury vapor is released from amalgam restorations in such teeth during steam autoclave sterilization. Mercury vapor detection, sample mass changes and x-ray fluorescence data were collected from experimental steam autoclave sterilization of amalgam samples sealed in autoclave bags. All of the data showed evidence of mercury vapor generation coincident to steam autoclave sterilization. Mercury vapor levels within the room where amalgam was exposed to steam autoclave sterilization reached levels that constitute an unnecessary health risk to dental personnel. The volume of amalgam tested simulated that contained in 175 amalgam restored teeth. Initial venting of the autoclave chamber produced mercury vapor concentrations significantly in excess of OSHA vapor concentration ceiling levels. Thus, the use of a steam autoclave for sterilization of amalgam containing teeth for use in preclinical laboratory exercises may be harmful to personnel involved.
Subject(s)
Dental Amalgam/chemistry , Mercury/chemistry , Sterilization/methods , Air Pollutants, Occupational/analysis , Air Pollution, Indoor/analysis , Dental Alloys/analysis , Dental Alloys/chemistry , Dental Amalgam/analysis , Dental Restoration, Permanent , Humans , Laboratories, Dental , Mercury/analysis , Occupational Exposure , Risk Factors , Spectrometry, X-Ray Emission , Steam , Sterilization/instrumentation , Thermogravimetry , United States , United States Occupational Safety and Health Administration , Ventilation , Volatilization , WorkforceABSTRACT
RadioVisioGraphy (RVG), a new digital imaging technique, is compared to conventional transcranial radiographic imaging of the temporomandibular joint. The results of this study using fixed human cadaver specimens revealed an excellent correlation between the recorded images and the actual anatomic specimens. Dosimetry, using a beryllium-windowed ionization chamber, showed a 64% dose reduction with charge-coupled device (CCD) when compared to standard film-screen combination.
Subject(s)
Radiography, Dental/methods , Temporomandibular Joint/diagnostic imaging , Aged , Analysis of Variance , Humans , Image Processing, Computer-Assisted , Middle Aged , Radiation Dosage , SemiconductorsSubject(s)
Acrylic Resins , Denture Design , Denture, Partial, Temporary , Splints , Surface PropertiesABSTRACT
The procedure described can allow correlation of clinical recordings of the patient's centric position with articulated working casts, thereby potentially eliminating most of th occlusal adjustments required when the restoration is seated in the mouth.
Subject(s)
Centric Relation , Crowns , Denture Design , Jaw Relation Record , Dental Occlusion, Balanced , Denture Design/instrumentation , HumansABSTRACT
A technique is presented to facilitate the fabrication of single or multiple restoration die working casts. The technique allows a full remount potential for use especially in multiple centric relation record verification techniques. A die removal technique that will not damage the brass dowel pin is suggested.
Subject(s)
Models, Dental , Dental Casting Technique , Dental Occlusion, Balanced , Equipment DesignSubject(s)
Periodontal Prosthesis , Periodontal Splints , Tooth Mobility/therapy , Adult , Equipment Design , Female , Humans , Middle AgedABSTRACT
There still is conflict among practitioners and researchers concerning the systemic effects of epinephrine retraction systems. However, the concentration of epinephrine in our commercially available retraction systems, as reported by Shaw, is cause for concern. Therefore, before using these systems, the dentist must consider the following variables: medical history of the patient, health of the oral cavity (especially the dentogingival unit), type of procedure to be done, amount and length of retraction, and exposure of the vascular bed. After careful attention to the foregoing variables, the retraction system of choice is the 8% racemic epinephrine-impregnated retraction cord. In addition to these variables, a calm and organized manner in the dental operatory can and will reassure the patient of the best of care with the least side effects.
Subject(s)
Dental Impression Technique/instrumentation , Epinephrine/pharmacology , Racepinephrine , Blood Vessels/drug effects , Cardiovascular System/drug effects , Denture Design , Denture, Partial, Fixed , Epinephrine/administration & dosage , Heart/drug effects , HumansSubject(s)
Crowns , Gutta-Percha , Post and Core Technique , Root Canal Therapy/instrumentation , Dental Instruments , HumansABSTRACT
1. Segments of the margin with porcelain adjacent to them did not change more than those without porcelain. 2. The marginal opening in the specimen made from the higher strength metal increased more than those made from the lower strength metal.
