Helvetica odontologica acta最新文献

Details of the decrease of DMT experience from 1963/64 to 1971/72 attained with the aide of the "Caries-Preventive Program" in 16 communities were investigated. The number of extracted molars decreased sharply, while the number of extracted premolars increased slightly. These shifts and a slightly later eruption of premolars did not materially affect the validity of overall DMF counts. Findings in first molars indicated long-term persistence of the lowered DMF experience. Fissure and pit caries of molars was reduced by 24 to 27 percent. Caries on free smooth surfaces of molars and on approximal surfaces of anteriorteeth showed decreases by 76 to 82 percent. Dentinal radiolucenices observed on lateral bite-wing radiographys were reduced by 47 to 52 percent. When the small radiolucencies confined to the enamel were included in the DMFS count, the reduction ranged between 23 and 27 percent.

A method for tooth surface lustre measurements with a scanning reflectance sensor system is described. A fiber optic light beam of high intensity is projected onto the labial tooth surface. The reflected light at position X is conducted through the same fiber optic to a photodiode, amplified and recorded on an X-Y recorder. Position X is measured by a potentiometer in the rotation center of a rod to which the fiber optic head is attached and which can be moved parallel to the arcade of anterior teeth to be measured. The experimental system allows the assessment of differences in light reflection caused by light scattering resulting from roughened enamel surfaces and by stains.

A new telemetric system was used to determine, simultaneously, plaque pH and salivary fluoride when sucrose-containing fluoride tablets of 0.25 mg and 1.0 mg NaF were dissolved in the oral cavity. Dissolution of 1.0 mg fluoride tablets on the dorsum of the tongue produced transient interproximal plaque acidification not lower than pH 5.2 combined with an increased salivary F-level between 0.19 and 19 ppm for up to 1 hr at the entrance of the interproximal space. Interference of plaque glycolysis by F was evident when rinsings with 250 ppm F as NaF combined with 10% sucrose resulted in pH levels 1/2-1 unit higher than with 10 percent sucrose alone. The use of sucrose as a vehicle in fluoride tablets is discussed.

Labial enamel surfaces of anterior teeth were polished, etched for thirty seconds with acid and then repolished by manual brushing with three different abrasive pastes for 10, 15, 15, 20, and 20 seconds respectively and finally for a 60-sec brushing with a dental engine. Before etching and following each paste treatment, the light reflection of the surfaces was measured with the scanning tooth surface reflectometer of GABATHULER. The reflectance values were compared with the microscopic tooth surface texture. Reflectometric findings were similar under in vitro and in vivo conditions. There were differences among the pastes in restoring maximum lustre of dull etched enamel, but not in polishing intact tooth surfaces.

Three experiments performed on Osborne-Mendel rats tested the effects on erosion of the topical application of aluminum, cerium and titanium salts as well as sodium fluoride and sodium mono-fluorophosphate. In two experiments the compounds were applied during the erosion period and in a third trial, the test substances were applied prior to exposure to the erosive agent which was fermented apple juice. While cerium had no significant effects on erosion, aluminum fhloride and titanium chloride significantly increased the severity of erosive tooth destruction. Only sodium fluoride and sodium mono-fluorophosphate were effective in preventing erosion.

The influence on the glycolytic activity of dental plaque of different amine-hydrochloride compounds 300, 315 and 356 (oleylamine) respectively at concentrations equimolar to their corresponding amine fluorides 297, 242 and 335 at 250 ppm F-concentrations and of hexetidine and sodium laurylsulfate was tested in an in vivo/in vitro combination. Hexetidine and sodium laurylsulfate were assessed at concentrations equimolar to compound 315. After having refrained from oral hygiene for three days four test subjects rinsed for 3 minutes with 10 ml H2O. Plaque was collected from interdental areas immediately after the control water rinse and 6 and 60 minutes after rinsing for 3 minutes with 10 ml of test solution. The plaque then was exposed in vitro to 10% glucose solution, and pH-decreases due to glycolysis were recorded for 30 minutes. Rinsing with amine chlorides resulted in strong inhibition of glycolytic activity 6 minutes as well as 1 hour after rinsing. Hexetidine and sodium laurylsulfate did not depress the fermentation of glucose.

The average individual status of gingival inflammation was evaluated in two groups of 39 and 47 subjects by means of the Gingivitis Fluorescein Test (GFT) and the Sulcus Bleeding Index. The subjects of the test group received a prophylaxis and hygiene instructions which were effective in reducing the gingivitis after 12 days. However, the reduction was not paralleled by a simultaneous decrease of fluorescein recovered in mouthwashings. The oral hygiene of the control group's subjects was not altered and examinations were performed after 7 days. In both groups the average SBI-score did not exceed 1.2 in all examinations. The fluorescein content of the mouthwashings was approximately 10 times reduced when compared with previous findings. No correlation was found between the amounts of fluorescein in mouthwashings and the severity or extent of the clinically assessed gingival inflammation.