Evaluation of silver methenamine method for nanoleakage.
OBJECTIVE
The aim of this study was to evaluate nanoleakage patterns following silver methenamine staining of restorations bonded with a total-etch single bottle system, a self-etching primer system and a total-etch single bottle system after collagen depletion.


METHODS
The dentin bonding systems used in this study were Prime and bond 2.1 (PB) and Clearfil SE Bond (CSEB). Cavities were made in grounded labial surfaces of 15 extracted bovine lower incisors, randomly divided into 3 Groups. Group 1 (PB), Group 2 (CSEB) and Group 3 (PB/SH) PB after collagen depletion with sodium hypochlorite (SH). The specimens were restored, sectioned and submitted to silver methenamine staining, polished and observed with low-vacuum back-scattered SEM. One way ANOVA and multiple-comparison Tukey's test were used for statistical analysis of the leakage scores.


RESULTS
PB presented significantly greater silver deposition and a distinct pattern when compared to CSEB. No silver deposition was detected for PB after collagen depletion.


CONCLUSIONS
The dentine bonding systems tested were unable to prevent nanoleakage when used according to the manufacturers' instructions; however, CSEB presented a lower level of silver deposition. Collagen depletion prior to PB application may prevent nanoleakage occurrence in dentine walls. Silver methenamine staining may be a useful method for detection of nanoleakage in dentine when the collagen fibrils remain exposed within the hybrid layers.
Fernando de Goes
Mario
M
Department of Restorative Dentistry/Dental Materials, School of Dentistry of Piracicaba-UNICAMP, Piracicaba, SP Brazil.
Montes
Marcos Antonio Japiassú Resende
MA
D000096:Acetone / Q000737:chemistry; D000134:Acid Etching, Dental; D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D003094:Collagen / Q000737:chemistry; D004396:Coloring Agents; D003763:Dental Leakage / Q000175:diagnosis*; D003793:Dental Restoration, Permanent; D003804:Dentin / Q000648:ultrastructure; D008422:Materials Testing; D008709:Methenamine; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D016877:Oxidants / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry*; D012973:Sodium Hypochlorite / Q000737:chemistry; D013499:Surface Properties
C438313:Clearfil SE Bond; D004396:Coloring Agents; D016877:Oxidants; D011109:Polymethacrylic Acids; D019279:Resin Cements; C444444:prime and bond 2.1; D000096:Acetone; D003094:Collagen; D012973:Sodium Hypochlorite; D008709:Methenamine