Faculty Bibliography

Faced with the challenge of restructuring a preclinical curriculum to provide a stronger background in general dentistry, a clinical simulation program that emphasizes critical thinking in clinical decision-making was developed and implemented at New York University College of Dentistry. The program offers an integrated program in clinical sciences focused on the faculty-defined outcomes for a general dentist. The curriculum was developed using outcomes that must be met before full patient care privileges are extended. The curriculum is centered around a series of patients with differing profiles of risk, disease, and treatment needs. Students are required to think globally, collect data that leads to an accurate assessment of the patient's risk, plan prevention and health promotion, and define a treatment plan. The student then demonstrates proficiency in executing treatment, evaluates the results, and speculates about the long-term impact of the treatment provided. Student and faculty evaluations are discussed as well as the strengths and shortcomings of the curriculum

In situ remineralization of early enamel lesions by a fluoride chewing gum was studied. Human enamel specimens with subsurface lesions were mounted in removable lower appliances for 6 adults. Subjects used a F-free dentifrice 3x/day and chewed five sticks/day for the F gum group (0.1 mg F/stick) or five sticks of sugarless gum. No gum was chewed for controls. Surface microhardness was performed on: (1) sound enamel; (2) lesions; (3) after intraoral exposure, and (4) after acid-resistance testing (ART). Separate specimens were etched and measured for F uptake and image analyses on microradiographs were performed for all regimens. delta Z values were calculated and converted to percent of mineralization. Values for F gum were significantly higher (p > 0.05) than non-F gum and controls for ART, percent remineralization, and F uptake up to 70 microns depth

A variety of intra-oral model systems has evolved which allows for the study of remineralization of coronal and/or root-surface lesions following application of topical fluoride (F) agents. The problem of interpretation of the results has led to a variety of analytical methods (i.e., microhardness, F biopsy, microradiography, and polarizing light microscopy), each of which provides important but limited information related to the overall understanding of remineralization. Microhardness measures change in mineral content which is more precisely localized by microradiography and polarized light microscopy. F biopsy allows for assessment of the F uptake of lesions, but does not suggest the chemical state of the F. Previous work has demonstrated that patterns of mineral deposition during remineralization do not necessarily parallel the F uptake profiles, and fluoridated apatites cannot be distinguished from non-specifically-adsorbed F (Clark et al., 1988). Because artificial lesions demonstrate variations in depth and mineral content, complementary analytical methods that demonstrate profiles of both F content and mineral density curves on the same section are needed so that the process of remineralization can be more clearly understood. This study used secondary ion mass spectrometry (SIMS) for F profiles and quantitative microradiography for assessment of mineral deposition on the same section. These state-of-the-art methods demonstrate the precision with which information about remineralization can be obtained. Subsurface lesions in human enamel specimens were developed by immersion in 0.1 M lactate buffer with 1% CMC at a pH of 4.5 for 48 h.(ABSTRACT TRUNCATED AT 250 WORDS)

For patients aged 5 to 9 and 11 to 14, 100 occlusal surfaces on newly erupting permanent molars were treated with a self-curing pit and fissure sealant. All teeth were categorized according to stage of eruption and sealant thickness of the coating applied. After 36 months, 75 surfaces were examined for a final evaluation; 52 surfaces (70%) did not need retreatment. Of the 23 surfaces retreated as a result of sealant loss or marginal deterioration, 18 were retreated only once in the six recall evaluations. Those molars treated originally with the operculum covering the distal marginal ridge of the occlusal surface had twice the probability for retreatment as teeth not treated until the entire marginal ridge was exposed. The thickness of the sealant coating did not affect the early signs of sealant failure

The purpose of this investigation was to study the intra-oral remineralization of acid-softened enamel by a NaF dentifrice compared with that from a combination of topical F agents. Bovine enamel slabs were demineralized with 0.1 mol/L lactic acid at pH 4.0 for 14 hr and then mounted in a removable mandibular appliance. Control slabs were worn for 96 hr by seven adult males who brushed daily with a F-free dentifrice. Test slabs were brushed with a NaF dentifrice 4 x/day or with the same dentifrice 4 x/day and a 0.02% APF mouthrinse and a 0.4% SnF2 gel which were applied once/day for three days. The natural dentition was also brushed with the NaF dentifrice during both test periods. Microhardness testing was performed on sound enamel, and after acid-softening, intra-oral exposure (IOE), and acid resistance testing (ART) in 0.01 mol/L lactic acid at pH 4.0 for 24 hr. Control and test slabs were etched with 0.5 mol/L HC1O4 for from 15 to 60 sec. The F content was measured with a F electrode and PO4 by spectrophotometry. Contact microradiography and image analyses were performed on control and test slabs so that changes in mineral content resulting from treatment could be assessed. Both test groups were significantly harder after both IOE and ART than were controls, but no differences appeared between the effects of the two test groups. The F content of control slabs was significantly less than that of both test groups, and the combination-treated slabs showed greater F than did the dentifrice-treated slabs.(ABSTRACT TRUNCATED AT 250 WORDS)

The purpose of this investigation was to study the intra-oral effects of multiple daily applications of NaF lozenges upon acid-softened enamel. Bovine enamel slabs were softened with 0.1 mol/L lactate buffer at pH 4.0 for 14 hrs and subsequently mounted in a mandibular removable Hawley appliance. Control slabs were worn for seven days by eight adult male subjects who brushed their natural dentition daily with a fluoride-free dentifrice. Test slabs were exposed to one 0.55-mg NaF lozenge (0.25 mg F) 4x/day for seven days and the natural dentition brushed with a fluoride-free dentifrice. The efficacy of 0.25-mg F lozenges used 4x/day over that of a 1-mg F lozenge administered 1x/day was established by a pilot study with two subjects. Microhardness testing was performed after intra-oral exposure (IOE) and following immersion in 0.01 mol/L lactate buffer containing Ca and PO4 for 24 hrs at a pH of 4.0. Fluoride uptake was measured on separate control and test slabs after KOH wash and after acid-resistance-testing (ART). Recovery of microhardness following IOE was 40.9% for controls and 53.9% for treated slabs, while control slabs retained 1.3% resistance to ART, compared with 25.6% for test slabs. The F content of the control slabs was significantly less than that of lozenge-treated and lozenge-treated-ART slabs throughout the depth of the lesion. The F content of the lozenge-treated-ART slabs was significantly less than that of the lozenge-treated slabs only at the 0-5-microns depth.(ABSTRACT TRUNCATED AT 250 WORDS)

Among the anticaries benefits of fluorides is the remineralization of incipient carious lesions. There is increasingly convincing evidence that low-potency fluoride agents applied frequently are effective in remineralizing early carious lesions. This study of in vivo remineralization used an intraoral appliance with demineralized enamel slabs mounted in the appliance and an innovative method of fluoride delivery, the fluoride-releasing device, which releases a controlled amount of fluoride (0.3 mg fluoride every 24 hours) on exposure to saliva. After control and treatment periods of 7 and 30 days, the enamel specimens were removed from the appliance and evaluated for microhardness, acid resistance, and fluoride uptake. The treated specimens significantly exceeded the values of their corresponding controls in all parameters measured, indicating that considerable remineralization of the treated enamel had occurred at both 7 and 30 days. Although the longer period of treatment produced greater results, considerable effects were observed after 7 days. This model system provided for an in vivo environment to study the effects of treatment of the FRD and allowed for subsequent recovery of the enamel specimens for evaluation. The results of this study are encouraging with respect to the efficacy of a fluoride-releasing device but indicate that subsequent clinical testing of the effects of FRDs on incipient carious lesions in the natural dentition of human subjects is necessary