SEM analysis of sealant penetration in posterior approximal enamel carious lesions in vivo.
OBJECTIVE
To study the microstructure of sealant penetration in the enamel of in vivo sealed approximal noncavitated incipient caries lesions with and without a preceding bonding step.


METHODS
A total of 26 proximal noncavitated caries lesions were sealed in vivo, using a sealant in 13 premolars with orthodontic indication of extraction. Each tooth was randomly assigned to mesial or distal surface application of a sealant in the lesion area and in surrounding sound enamel, with or without a bonding system. Four groups were analyzed: a nonbonding group in the lesion area (NBL); a nonbonding group in sound enamel (NBS); a bonding group in the lesion area (BL) and a bonding group in sound enamel (BS). The premolars were extracted after two weeks. All sealed areas were cut and demineralized with 37% hydrochloric acid for 24 h. For each group, the resin tags were observed and measured by scanning electron microscopy.


RESULTS
The lesion areas showed a very irregular resin network with twisted and curved tags in contrast to the sound enamel where a regular etching pattern was observed. The length of resin tags in microns for each group (mean +/-SD) was: NBG-L = 4.19 +/- 1.59; NBG-S = 5.49 +/- 2.49; BG-L = 4.57 +/- 1.99; and BG-S = 4.21 +/- 1.87. The differences between the groups were not statistically significant (p = 0.34).


CONCLUSIONS
The use of a bonding system prior to the application of a pit and fissure sealant on both lesion and sound enamel areas does not increase the resin penetration length under non-contaminated conditions.
Gomez
Santiago
S
Department of Preventive Dentistry, Faculty of Dentistry, Valparaiso University, Valparaiso, Chile. santiago.gomez@uv.cl
Uribe
Sergio
S
Onetto
Juan Eduardo
JE
Emilson
Claes-Göran
CG
D000134:Acid Etching, Dental; D000293:Adolescent; D001641:Bicuspid / Q000648:ultrastructure; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002327:Cariostatic Agents / Q000627:therapeutic use; D003188:Composite Resins / Q000737:chemistry; D003648:Decalcification Technique; D001840:Dental Bonding / Q000379:methods; D003731:Dental Caries / Q000473:pathology* / Q000517:prevention & control; D003743:Dental Enamel / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D004311:Double-Blind Method; D005260:Female; D005460:Fluorides, Topical; D006801:Humans; D006851:Hydrochloric Acid / Q000737:chemistry; D008297:Male; D008855:Microscopy, Electron, Scanning; D063065:Organophosphonates / Q000737:chemistry; D010895:Pit and Fissure Sealants / Q000737:chemistry* / Q000627:therapeutic use; D012969:Sodium Fluoride / Q000627:therapeutic use; D013499:Surface Properties; D013997:Time Factors
D002327:Cariostatic Agents; C500418:Clinpro Sealant; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D005460:Fluorides, Topical; D063065:Organophosphonates; D010895:Pit and Fissure Sealants; C454540:Scotchbond etchant; C115612:single bond; C023807:sodium fluoride topical preparation; D017438:Bisphenol A-Glycidyl Methacrylate; D012969:Sodium Fluoride; D006851:Hydrochloric Acid