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Biomedical subjects

J Boffa

Publications and source records attributed to J Boffa.

29 records · Page 2Linked to original sources

The combined reversible hydrocolloid/irreversible hydrocolloid impression system.

1. Dentloid, a reversible hydrocolloid which had been altered to bond to irreversible hydrocolloid, demonstrated a bond with three irreversible hydrocolloids tested in combination with it. 2. Two conventional reversible hydrocolloids exhibited such weak bonding with irreversible hydrocolloid that it was impossible to make impressions with them. 3. The three irreversible hydrocolloids exhibited different bond strengths with Dentloid. 4. The Dentloid/irreversible hydrocolloid combination with the lowest bond strength exhibited the lowest dimensional stability. 5. Combined impressions of Dentloid with two of the three irreversible hydrocolloids exhibited dimensional stability that is a clinically acceptable. 6. Combinations of Dentloid with irreversible hydrocolloids not covered in this report should be verified for acceptable dimensional stability before clinical use. 7. The combination technique, in itself, proved to be easy and practical and overcomes many of the shortcomings inherent to conventional reversible hydrocolloid impression techniques. 8. Strict adherence to laboratory procedures for pouring a cast is as critical as for the conventional technique.

Chemical Phenomena↗

Hearing loss and the high speed dental handpiece.

A pure tone air conduction audiometric evaluation was administered to 137 dentists and 80 physicians. The physicians were found to have better hearing threshold levels, notably in the 4000HZ center frequency range. The left ear of right handed dentists showed a greater loss of hearing ostensibly related to proximity to the noise source. Dental specialists showed a loss pattern similar to those of the general dentists. The findings suggest that there may be a cause and effect relationship between hearing loss and use of the highspeed dental handpiece.

Adult↗

A longitudinal study of multiple approaches to dental health education.

An evaluation was made of the separate effects on oral hygiene of token reward treatments, discovery (project) learning, and plaque staining feedback demonstrations with children in the first through fifth grades. Both short- and long-term effects were assessed in an open classroom setting. Twenty classrooms were non-randomly assigned to treatment and control groups. Plaque scores were recorded according to the Podshadley Patient Hygiene Performance Index (PHP) at time T0, before initiation of any of the educational interventions; and again at times T1, T2, and T3; 7 days, 74 days and 255 days, respectively, following cessation of the educational interventions. The combination of dental health interventions at this school had short-range effects at every grade level, and those effects persisted for 9 months among the third and fourth graders. It was not possible to identify which of the various treatments produced the observed differences, although the project learning method was generally less effective. A linear regression analysis was used to evaluate the shifts in oral hygiene behavior, a method not previously used in studies of this type.

Child↗

A study of "broken appointment" patients in a children's hospital dental clinic.

Part I of this study investigated possible variables determining "High Risk No Show" behavior on the part of patients in a dental clinic. Only "source of payment" seemed important; namely, that Medicaid patients were statistically more likely to be "High Risk No Show" patients (P less than .001). Race was associated but was found to be confounded with Medicaid. In an attempt to investigate the reasons for the Medicaid group being "High Risk No Show" patients, Part II of the study compared three distinct groups of patients at the Children's Hospital Medical Center Clinic. These included the self-paying group and the Medicaid group of the original sample of 90 in addition to the Union plan group (patients receiving free third-party payment care as an employee benefit). It was shown that both groups with third-party coverage were associated with "High Risk No Show" behavior. The type of "No Show" behavior, however, was different for the two groups. Union plan patients tended to cancel appointments or at least notify in advance of inability to keep an appointment. Medicaid patients, conversely, were just as likely to fail appointments and not file advance notice of inability to keep an appointment.

Appointments and Schedules↗

A deep model of the incidence of dental caries on proximal surfaces.

As a component of an analysis of the benefits of alternative frequencies of bitewing radiographs to detect dental caries, the authors developed and validated a model to generate an individual's probability distribution for new carious lesions in a year. The model postulates two sources of variability in caries incidence--differences in individuals' underlying caries susceptibilities and a random component. The model is used to examine the nature of caries risk over time. The large random fluctuations in an individual's caries susceptibility from year to year, combined with the random nature of caries attack, makes it difficult to predict future caries experience from the individual's caries experience in the recent past. By modeling the process giving rise to observed incidence data rather than focusing directly on the observed data, i.e., by developing a deep rather than a surface model, the authors have elucidated underlying disease dynamics and provided a basis for generalizing from the particular data used to develop the model.

Adolescent↗