TY - JOUR
T1 - Enamel microhardness after in vitro demineralization and role of different restorative materials
AU - Savarino, L.
AU - Saponara Teutonico, A.
AU - Tarabusi, C.
AU - Breschi, L.
AU - Prati, C.
PY - 2002
Y1 - 2002
N2 - This study aimed to evaluate the extension of enamel demineralization around the margin of restorations after immersion in cariogenic solution, in an attempt to define the role of new restorative materials in preventing secondary caries formation. For this purpose, enamel microhardness was measured. Twelve class V restorations in human extracted third molars were prepared in vitro and immersed in a demineralizing solution (lactic acid, pH 4.5) at 37°C for 3 days to simulate the formation of secondary caries and its effect on the marginal integrity of composite restorations. The restorative systems tested in the study were Scotchbond 1 + Z 250 (group A), ABF + APX (group B), Fuji IX (group C), SE Bond + APX (group D), and Scotchbond 1 + F 2000 (group E). The microhardness was measured close to the margin of restoration (marginal exposed enamel), at 2.0 mm from the margin (exposed enamel), and at approximately 4 mm from the margin in a varnish-covered enamel area (protected enamel). Five measurements were made on each site at 20, 40, 60, 80, and 100 μm depth from the external enamel surface. Exposed enamel and marginal exposed enamel were greatly affected by the cariogenic solution, as confirmed by the high rate of demineralization. The marginal exposed enamel showed a higher rate of demineralization than the exposed enamel, as demonstrated by the lowest microhardness values. The materials that claimed fluoride release did not prevent any type of enamel marginal alteration. This study revealed that enamel close to the margin of restoration may be rapidly affected by secondary caries formation when immersed in a demineralizing-cariogenic solution and that fluoride-releasing materials are unable to reduce the marginal demineralization processes. These demineralization processes may be responsible for marginal secondary caries and for restoration failures.
AB - This study aimed to evaluate the extension of enamel demineralization around the margin of restorations after immersion in cariogenic solution, in an attempt to define the role of new restorative materials in preventing secondary caries formation. For this purpose, enamel microhardness was measured. Twelve class V restorations in human extracted third molars were prepared in vitro and immersed in a demineralizing solution (lactic acid, pH 4.5) at 37°C for 3 days to simulate the formation of secondary caries and its effect on the marginal integrity of composite restorations. The restorative systems tested in the study were Scotchbond 1 + Z 250 (group A), ABF + APX (group B), Fuji IX (group C), SE Bond + APX (group D), and Scotchbond 1 + F 2000 (group E). The microhardness was measured close to the margin of restoration (marginal exposed enamel), at 2.0 mm from the margin (exposed enamel), and at approximately 4 mm from the margin in a varnish-covered enamel area (protected enamel). Five measurements were made on each site at 20, 40, 60, 80, and 100 μm depth from the external enamel surface. Exposed enamel and marginal exposed enamel were greatly affected by the cariogenic solution, as confirmed by the high rate of demineralization. The marginal exposed enamel showed a higher rate of demineralization than the exposed enamel, as demonstrated by the lowest microhardness values. The materials that claimed fluoride release did not prevent any type of enamel marginal alteration. This study revealed that enamel close to the margin of restoration may be rapidly affected by secondary caries formation when immersed in a demineralizing-cariogenic solution and that fluoride-releasing materials are unable to reduce the marginal demineralization processes. These demineralization processes may be responsible for marginal secondary caries and for restoration failures.
KW - Composites
KW - Demineralization
KW - Enamel
KW - Fluoride-releasing materials
KW - Microhardness
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U2 - 10.1163/156856202320176574
DO - 10.1163/156856202320176574
M3 - Article
C2 - 12102599
AN - SCOPUS:0036283056
VL - 13
SP - 349
EP - 357
JO - Journal of Biomaterials Science, Polymer Edition
JF - Journal of Biomaterials Science, Polymer Edition
SN - 0920-5063
IS - 3
ER -