Adhesion of stainable, calcium-rich deposits on substrata with different surface free energies. An in vivo study in beagle dogs.
Calculus plays an important role in chronic inflammatory periodontal disease and tooth loss. Patients can suffer from calculus formation despite good oral hygiene. The strength of adhesion between calculus and the enamel surface, though not determinant for the formation of calculus itself, determines whether calculus remains on the teeth during eating and toothbrushing. In this study, the amount and the strength of adhesion of calcium-rich deposits formed in vivo on different materials are related to substrate surface free energies (sfe). In 4 beagle dogs, fenestrated crowns were made on the upper fourth premolars. Smooth facings of glass (sfe 120 mJ.m-2), polished bovine enamel (sfe 85 mJ.m-2), polymethylmethacrylate (PMMA sfe 56 mJ.m-2) and polytetafluorethylene (PTFE sfe 20 mJ.m-2) were inserted in the crowns for 1, 3, 7, 14 or 28 days. The amount of deposit was evaluated both gravimetrically and planimetrically using Alizarin Red S for staining. Adhesion of calcium-rich deposits was evaluated planimetrically by studying their removal in a brushing machine. Dry weight increased linearly with time (approximately 0.18 mg.cm-2 per day) and was slightly less on PTFE than on the other materials. After 1 to 3 days, staining already revealed a 100% coverage by calcium-rich deposits. The number of strokes required to reduce the planimetric scores by 63% was extremely small on PTFE and PMMA and related with substrate surface free energies. This study shows that a possible way to reduce calculus formation in vivo is to decrease the surface free energy of the enamel using appropriate surfactants in, e.g., toothpastes.
Uyen
H M
HM
Dental School, University of Groningen, The Netherlands.
van Dijk
L J
LJ
Busscher
H J
HJ
D000268:Adhesiveness; D000818:Animals; D000880:Anthraquinones; D002118:Calcium / Q000032:analysis / Q000378:metabolism*; D002417:Cattle; D004396:Coloring Agents; D003728:Dental Calculus / Q000032:analysis / Q000378:metabolism*; D003743:Dental Enamel / Q000378:metabolism; D003764:Dental Materials; D004285:Dogs; D005898:Glass; D008768:Methylmethacrylates; D011138:Polytetrafluoroethylene; D013499:Surface Properties; D013997:Time Factors; D014099:Toothbrushing
D000880:Anthraquinones; D004396:Coloring Agents; D003764:Dental Materials; D008768:Methylmethacrylates; C004468:Alizarin Red S; D011138:Polytetrafluoroethylene; D002118:Calcium