title: Influence of amalgams, bases, and varnish on seal composition at restoration tooth interfaces.
abstract: Eighty extracted, noncarious premolars were restored with one of 20 different combinations of restorative materials: a high- or low-copper amalgam, unlined or lined with one of five bases, and varnished or unvarnished. The teeth were aged in 1% NaCl and after 3 months and 1 year the seal material deposited on the cut tooth cavity surface and the surface of the amalgam restoration was analyzed by use of energy dispersive x-ray analysis. Atomic weight percentages of marginal seal elements were statistically examined with ANOVA and Tukey's test with significance set at p < 0.05. The results indicated that only one type of seal was formed centered around tin. More marginal seal material was present in the 1-year specimens. Restoration materials used affected the deposition rate of marginal seal material. Low-copper amalgam-restored teeth formed more seal material with significantly greater amounts of chlorine and tin. Less marginal seal material was found in varnished cavities. A calcium hydroxide base produced a thick marginal seal with a significantly different composition of elements compared with the unlined and zinc-based specimens. Tin in Poly-F Plus polycarboxylate cement did not significantly increase the tin content of the marginal seal. Base materials can play a role in determining crevice pH. The findings have bearing on improved longevity of amalgam restorations.
authors.affiliation: University of Witwatersrand, Johannesburg, South Africa.
authors.forename: E S
authors.initials: ES
authors.lastname: Grossman
authors.forename: M J
authors.initials: MJ
authors.lastname: Witcomb
authors.forename: J M
authors.initials: JM
authors.lastname: Matejka
mesh_terms: D000704:Analysis of Variance; D002126:Calcium Hydroxide; D003343:Corrosion; D003722:Dental Alloys; D003723:Dental Amalgam / Q000737:chemistry*; D003736:Dental Cavity Lining; D018772:Dental Marginal Adaptation; D004338:Drug Combinations; D004577:Electron Probe Microanalysis; D005054:Eugenol; D005557:Formaldehyde; D006801:Humans; D007764:Lacquer; D008903:Minerals; D011076:Polycarboxylate Cement; D014001:Tin; D015034:Zinc Oxide
chemical_list: D003722:Dental Alloys; D004338:Drug Combinations; D008903:Minerals; D011076:Polycarboxylate Cement; D005557:Formaldehyde; C033470:Dispersalloy; C031359:New True Dentalloy; D005054:Eugenol; C029881:Poly F cement; C025702:Dycal; D014001:Tin; D003723:Dental Amalgam; C003799:N2 Dental Cement; D002126:Calcium Hydroxide; D015034:Zinc Oxide