P.-G. Jost-Brinkmann

Ultrasonographic measurement of tongue movement during swallowing

Previous ultrasonographic studies on tongue functions were limited by the possibility of artifacts caused by movement of the submental area during function. Consequently, tongue movements were misinterpreted. A dynamic tongue imaging technique, the cushion‐scanning technique, was used to overcome this problem. Later, swallowing was investigated and divided into five phases using cushion‐scanning technique‐aided M‐mode ultrasonograms. In this study, cushion‐scanning technique in combination with the B‐mode and M‐mode ultrasonography was applied to investigate and measure the tongue movement during swallowing in 55 normal persons. The average duration, range of motion and speed of swallowing were found to be 2.43 s, 24.06 mm, and 10.34 mm/s, respectively. The computer‐aided B‐mode plus M‐mode ultrasonography in combination with the cushion‐scanning technique is a valuable tool for study of tongue functions.

Light-cured glass ionomer cement as a bracket adhesive with different types of enamel conditioners.

Zusammenfassung80 Rinderfrontzähne wurden mit Siliziumkarbidschleifpapier (320er Körnung) plangeschliffen und die Schmelzoberflächen mit fluoridfreier Prophylaxepaste poliert. Die Schmelzoberflächen der einzelnen Gruppen wurden wie folgt konditioniert: 1. Keine Konditionierung; 2. Salicylsäure (10%, 10 s); 3. Benzoesäure (10%, 10 s); 4. Bestrahlung mit Natriumhydrogencarbonat/Prophy-Jet®; 5. Prophy-Jet®, anschließend 10%ige Polyacrylsäure (PAS); 6. PAS, anschließend Speichelkontamination; 7. PAS; 8. Phosphorsäure (37%). Als Bracketkleber in Gruppe 1 bis 7 diente Fuji Ortho II LC® (GC), in der Kontrollgruppe Concise orthodontic® (3M). Per Hand wurden Stahllingualknöpfchen positioniert. Die Polymerisation erfolgte für je 20 s von inzisal, mesial, gingival und distal mit sichtbarem Licht. Nach 24 Stunden Lagerung in Wasser (23°C) wurde die Scherfestigkeit entsprechend ISO-Spezifikation Entwurf TC 106/SC2/WG16 getestet. Die Scherkräfte wurden mittels Student-test verglichen und auf Signifikanz geprüft. Die höchste mittlere Scherfestigkeit (im Vergleich zur Kontrollgruppe) wurde in Gruppe 1 (PAS, 28 MPa) erreicht. Diese unterschied sich sowohl signifikant (p=0,04) von der Kontrollgruppe (Concise®, 33 MPa) als auch hochsignifikant von den restlichen Gruppen (<16 MPa). Die Scherfestigkeit von Fuji Ortho II LC® bei Schmelzkonditionierung mit Polycrylsäure legt die klinische Verwendung dieses Materials als Bracketkleber nahe.SummaryEighty bovine incisors were ground on 320-grit sillicone carbide paper and cleaned with fluoride-free prophylaxis paste. The enamel surface conditions were: 1. no conditioning; 2. salicylic acid (10%, 10 s); 3. benzoic acid (10%, 10 s); 4. airpolishing with sodium hydrogen carbonate/Prophy-Jet®; 5. Prophy-Jet®, followed by polyacrylic acid (PAA, 10%, 10 s); 6. PAA, followed by saliva contamination; 7. PAA; 8. phosphoric acid (37%, 10 s). Fuji Ortho II LC® (GC) was used as a bracket adhesive in groups 1 to 7, and in group 8 Concise® orthodontic (3M). Stainless steel lingual buttons were placed by hand. Polymerisation with visible light was carried out 20 s from mesial, distal, incisal and gingival. After 24 h storage in tap water at room temperature the shear bond strengths were tested in accordance with ISO specification TC 106/SC/WG16. Mean values of the groups were compared using Students t-test. Group 7 (PAA) attained the highest mean shear strength (in comparison with control group): 28 MPa. This was both significantly different from the control group (Concise®, 33 MPa) and highly significant in comparison with the other groups (<16 MPa). The shear bond strength of Fuji Ortho II LC® on PAA conditioned enamel indicates the clinical applicability of this material.Eighty bovine incisors were ground on 320-grit silicone carbide paper and cleaned with fluoride-free prophylaxis paste. The enamel surface conditions were: 1. no conditioning; 2. salicylic acid (10%, 10s); 3. benzoic acid (10%, 10s); 4. air polishing with sodium hydrogen carbonate/Prophy-Jet; 5. Prophy-Jet, followed by polyacrylic acid (PAA, 10%, 10 s); 6. PAA, followed by saliva contamination; 7. PAA; 8. phosphoric acid (37%, 10 s). Fuji Ortho II LC (GC) was used as a bracket adhesive in groups 1 t0 7, and in group 8 Concise orthodontic (3M). Stainless steel lingual buttons were placed by hand. Polymerisation with visible light was carried out 20 s from mesial, distal, incisal and gingival. After 24 h storage in tap water at room temperature the shear bond strengths were tested in accordance with ISO specification TC 106/SC/WG16. Mean values of the groups were compared using Students t-test. Group 7 (PAA) attained the highest mean shear strength (in comparison with control group): 28 MPa. This was both significantly different from the control group (Concise, 33 MPa) and highly significant in comparison with the other groups (< 16 MPa). The shear bond strength of Fuji Ortho II LC on PAA conditioned enamel indicates the clinical applicability of this material.