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Biomedical subjects

F N Weber

Publications and source records attributed to F N Weber.

9 recordsLinked to original sources
PubMed1979

Enamel decalcification in orthodontic treatment.

One hundred twenty previously extracted premolar teeth were used in this study. Teeth were divided into five groups of twenty-four each. The first group was treated with Copalite, the second with Portrait Veneer, the third with a polymeric adhesive coating material (Protecto), the fourth group with Nuva-Seal, and the fifth group served as a control. Orthodontic bands were selected and cemented to each tooth. The cement seal was then broken and teeth were thermocycled to simulate an in vivo condition. All teeth were then submerged in a decalcifying gelatin for 21 weeks. Every group was further broken into three equal subdivisions. Division A was to be submerged for 7 weeks, Division B in each group was to be submerged for 14 weeks, and Division C was to be submerged for 21 weeks. At each time interval, teeth were cleaned and examined for decalcification. Data were recorded and analyzed by means of the chi-square test. It was found that acid-etching materials protect the teeth against decalcification best. Among the acid-etching materials used, Nuva-Seal proved to be the best at protecting the teeth against decalcification for 21 weeks with this experimental design.

Acid Etching, Dental↗
PubMed1977

Impressions!!

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Dental Care↗
PubMed1976

Preventing enamel decalcification during orthodontic treatment.

One hundred thirty-two extracted premolar teeth were selected and divided into four equal groups. The first group of thirty-three teeth received a topical application of acidulated phosphate fluoride; the second group, a topical application of stannous fluoride; the third group, an application of a polymeric adhesive coating; the fourth group was left untreated to serve as a control. On each tooth a loosely fitted orthodontic band was cemented to place. After cementation, the band was broken to simulate a loose orthodontic band in vivo. The four groups of teeth were simultaneously immersed in a decalcifying gelatin and were left undisturbed for 11 weeks. The teeth were then removed and a record was made of the decalcification produced. A chi-square test was used to compare the teeth in each group to those in every other group. Compared to a control group of teeth, those teeth treated with polymeric adhesive coating, acidulated phosphate fluoride, or stannous fluoride produced a statistically significant reduction in decalcification of the tooth surfaces beneath loose orthodontic bands. For a one-application technique, the polymeric adhesive coating provided more protection against decalcification of teeth under loose orthondontic bands than did either acidulated phosphate fluoride or stannous flouride.

Calcium Metabolism Disorders↗
PubMed1976

Shear strength of orthodontic direct-bonding adhesives.

A total of 210 double-width stainless steel edgewise brackets with retentive lip bases were bonded to bovine incisors with seven commercially available direct-bonding materials. Ten samples for each of the seven direct-bonding materials were tested for shear strength using the Instron Universal Testing Instrument. The samples were tested after 1 day, 1 month, and 3 months of immersion in 30 per cent physiologic saline solution. The mean shear strength of each direct-bonding material at each time interval was compared statistically to the mean shear strength of each of the materials at each time interval with a matched 1 test. The same test was used to determine whether there had been a significant change in mean shear strength from start to finish of testing for each material. One product showed a significantly better mean shear strength than any other material at each test interval. The remaining materials were grouped in middle or low ranges, depending upon their final mean shear strengths and degrees of nonsignificance when compared to each other.

Acrylic Resins↗