The effects of different storage conditions on polyether and polyvinylsiloxane impressions.

While being shipped to a laboratory, impressions can be exposed to excessive temperatures. This study compared the effects of different time and temperature storage conditions, including temperature extremes of 66 C and -10 C, on the accuracy of addition silicone and polyether impressions. The greatest distortion generally occurred as a result of the 66 C temperature extreme.

Career changers: dentists who choose to leave private practice.

Some dentists have voluntarily chosen to leave the dental profession despite the considerable time, effort, and financial expenditures involved in their educations. The purpose of this study was to survey the entire population of dentists who had identified themselves as being principally employed in a career outside of clinical practice in the American Dental Association's 1991 Census. A four-page survey was mailed to 654 former dentists, with a total of 237 usable responses (36%).

Histologic evaluation of porcine skin incisions produced by CO2 laser, electrosurgery, and scalpel.

The purpose of this study was to histologically compare the healing of porcine skin incisions made by CO2 laser, electrosurgery, and conventional scalpel. Incisions were made on the dorsal thorax of two microswine at staggered time intervals allowing the harvest of specimens at 0, 4, 7, 14, and 21 days postsurgery at the time of sacrifice. Each of the following histologic zones were identified and measured for both laser and electrosurgery incisions: (1) zone of tissue ablation.

Pilot study comparing parents' and third-grade schoolchildren's attitudes toward braces and perceived need for braces.

An instrument developed for third-grade schoolchildren and their parents was pilot-tested for its ability to measure orthodontic attitudes and perception of the child's need for braces. Seventy-eight children and 54 parents were surveyed. Forty-six percent of the children wanted braces while 61% believed that they needed braces.

Effects of the Nd:YAG laser and combined treatments on in vitro fibroblast attachment to root surfaces.

The purpose of this in vitro study was to evaluate the effects of the Nd:YAG laser either alone or in combination with root planning or air-powder abrasive treatment on fibroblast attachment to non-diseased root surfaces. 28, 4 x 4 mm root specimens and four disc-shaped root specimens 6 mm in diameter were obtained from unerupted 3rd molars. The root segments were randomly assigned to 4 treatment groups: (1) control; (2) laser-only treated; (3) laser treated followed by root planning; (4) laser treated followed by air-powder abrasive treatment.

How personal protective equipment affects perceptions of dentists.

In this study, 248 college-educated young adults completed the Dental Fears Survey. Subjects then viewed one of two slides of a dentist. In one slide, the dentist wore no PPE at all; in the other, the dentist wore gloves, mask, glasses, face shield and lab coat.

Effect of vitamin C and vitamin E on prostaglandin synthesis by fibroblasts and squamous carcinoma cells.

Dietary levels of vitamins C and E have been associated with cancer prevention and to a lesser extent with therapeutic enhancement of cancer treatment. Inhibition of prostaglandins (PGs) by pharmacological agents has been demonstrated to enhance immunocompetence, and to suppress growth of tumors in animals and humans. We report here on the effect of vitamins C and E on PGE2 production by human gingival fibroblasts and SCC-25 oral squamous carcinoma cells.

Impact of overbite on indicators of temporomandibular joint dysfunction.

Epidemiological studies have suggested that deep overbite is associated with symptoms of temporomandibular dysfunction (TMD). This finding was directly tested by deliberately constituted groups of deep and normal overbite subjects matched for age and sex. Eighty-one subjects participated.

Oral presentation of Wegener granulomatosis.

Although the mouth is often involved in Wegener granulomatosis, oral lesions as the initial sign are rare. This case report documents the importance of considering Wegener granulomatosis in patients with unique oral lesions. The most common lesion is a friable-granular-hyperplastic gingivitis associated with alveolar resorption and tooth mobility.

Restoration of mandibular continuity defects using combinations of hydroxylapatite and autogenous bone: microscopic observations.

The purpose of this investigation was to assess by light, transmission, and scanning electron microscopy the healing of mandibular continuity defects reconstructed with varying ratios of an alloplastic hydroxylapatite implant material (HA) mixed with autogenous bone (AB). This study reports the microscopic observations of implant and control sites at 6 and 18 months postsurgery. The results confirm the biocompatibility of dense HA granules.

The effectiveness of a leadup activity on performance in an operative preclinic laboratory course.

Preclinical technique curricula seldom provide training in those prerequisite skills that may facilitate performance in a large class of procedures. Instead, students typically progress from simple to increasingly difficult preparations and it is assumed that positive transfer occurs between them. Another strategy that may provide greater benefits is the leadup activity, which closely simulates the criterion tasks, but eliminates one or more complexities thought to interfere with prerequisite skill acquisition.

A theory of motor performance and its applications to preclinical dental skill acquisition.

This article reviews one theory of motor performance that was derived from a large body of research findings. The validity of any theory depends on the extent to which it can generate testable hypotheses. Based on a number of applied investigations in the preclinical setting, several predictions developed from this theory have been supported.

The effect of knowledge of the desired outcome on dental motor performance.

Knowledge of the desired outcome of a series of movements is a critical component of motor performance, since it is used to develop the appropriate motor program and to form a basis for understanding terminal extrinsic feedback and formulating subjective reinforcement. In dentistry, information about the desired outcome is almost always disseminated in a lecture and laboratory manual, and a demonstration often is provided. However, mastery by students usually is not given the importance it deserves.