Efeito do PMSF na incorporação de fluor e remineralização do esmalte dental

AUTOR(ES)
DATA DE PUBLICAÇÃO

1997

RESUMO

Phenylmethylsulfonylfluoride (PMSF) is a widely used protease inhibitor that by releasing fluoride may have indirect effect on enzymes, pellicle formation and dental enamel. The objective of this research was to study the effect of PMSF on enamel remineralization through saliva action. Forty nine flat bovine enamel blocks (4x4mm) were used. Surface microhardness (SMH) was initially determined in the sound enamel. These enamel blocks were partially demineralized in 0.05 M lactic acid, 50% saturated hydroxiapatite sol. at pH 5.0 containing Carbopol 0.2%, during 16h at 37°C. SMH was determined again; the enamel blocks were randomly allocated in 5 groups and submitted to the following treatments: 1= Human Stimulated Saliva (HSS); II= HSS containing 10.0 `mu´M PMSF; III= HSS containing 50.0 `mu´M PMSF; IV= HSS containing 100.0 `mu´M PMSF and V= HSS containing 1.0 ppm F. The enamel blocks were submitted to a pH-cycling model for 12 days, kept 2h in demineralizing solution and 22h in HSS. The saliva was changed twice/day and the demineralizing sol. after the 6th day. The Knoop SMH was again determined. Enamel fluoride uptake was determined by removing 5 layers of enamel With 0.5 M HCL. Fluoride released from PMSF (100.0 `mu´M) through saliva action was determined. For the Knoop SMH analysis a microhardness tester SHIMADZU HMV -2000 was utilized and for the fluoride analysing, specific electrode ORlON 96-09 was utilized. The results showed that PMSF, releases fluoride and after 10 minutes at 37°C, the fluoride concentration in saliva increased significantly from 0.078 to 1.732 ppm F. The % of Knoop SMH recovery (mean + SE) was calculated; the results for the groups I to V were respectively: 10.7 `+ or -´1.97A; 30.8 `+ or -´2.90B; 43.5 `+ or -´ 5.07B,C; 54.5 `+ or -´ 6.59C; and 43.2 `+ or -´ 5.82B,C. The results (mean `+ or -´ SE) of enamel fluoride uptake (ppm) at the 1st layer were: 2544.8 `+ or -´ 203.7A; 6281.0 `+ or -´ 429.9B; 13732.7 `+ or -´ 1372.8C; 13719.0 `+ or -´ 1552.1C; and 11650.3 `+ or -´ 1394.2C. Means followed by different letters are statistically significant (p<0.05). In conclusion, PMSF releases fluaride when in contact with saliva, which not only enhances remineralization and enamel fluoride uptake but may also have indirect effects on other researches where PMSF is used as protease inhibitor

ASSUNTO(S)

inibidores enzimaticos proteoliticos saliva fluor

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