Microleakage at sealant/enamel interface of primary teeth: effect of Er:YAG laser ablation of pits and fissures.
OBJECTIVE
The objective of this study was to assess microleakage at sealant/enamel interface after treatment of primary teeth occlusal surfaces with 3 etching techniques.


METHODS
Thirty sound primary molars were randomly assigned to 3 groups (N = 10): (1) group I = acid etching for 30 seconds; (2) group II = Er:YAG laser (120 mJ; 4 Hz) plus acid-etching; and (3) group III = Er:YAG laser (120 mJ; 4 Hz). Pits and fissures were sealed with a resin-based sealant (Fluroshield, Dentsply/Caulk). Teeth were isolated, thermocycled, immersed in a 0.2% rhodamine B solution for 24 hours, and serially sectioned. Cuts were analyzed for leakage using an optical microscope connected to a video camera. The images were digitized, and a specific software (Axion Vision) assessed microleakage quantitatively (millimeters). The sealant extension on buccal/lingual cusp heights was measured separately, and the percentage of dye penetration along enamel/sealant interface, in relation to the sealant extension, was calculated. Means of dye penetration were: (1) group I = 2%(+/- 3.75); (2) group II = 2%(+/- 3.38); and (3) group III = 4%(+/- 6.26). Data were submitted to ANOVA and Tukey test.


RESULTS
A statistically significant difference (P < .05) was observed between the nonetched lased specimens (group III) and those in the other groups. No significant difference (P >.05) was found between the acid-etched and lased/acid-etched groups (I and II). Fissures prepared with Er:YAG laser alone showed the highest degree of microleakage. All specimens exhibted some degree of leakage.


CONCLUSIONS
Laser irradiation did not eliminate the need for acid etching enamel prior to the placement of a pit-and-fissure sealant. The ablation of pits and fissures with an Er:YAG laser device did not yield significantly better marginal sealing at primary enamel/sealant interface, compared to conventional acid etching.
Borsatto
Maria Cristina
MC
Department of Pediatric Clinic, Preventive, and Social Dentistry, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto- São Paulo, Brazil. borsatto@forp.usp.br
Corona
Silmara Aparecida Milori
SA
Ramos
Renata Pereira
RP
Liporaci
Jorge Luiz Jacob Júnior
JL
Pécora
Jesus Djalma
JD
Palma-Dibb
Regina Guenka
RG
D017438:Bisphenol A-Glycidyl Methacrylate; D003737:Dental Cavity Preparation / Q000379:methods*; D003743:Dental Enamel; D045662:Dental Etching / Q000379:methods*; D003750:Dental Fissures; D003763:Dental Leakage / Q000517:prevention & control*; D003793:Dental Restoration, Permanent / Q000379:methods; D004871:Erbium; D006801:Humans; D053685:Laser Therapy; D010895:Pit and Fissure Sealants; D011140:Polyurethanes; D014094:Tooth, Deciduous
D010895:Pit and Fissure Sealants; D011140:Polyurethanes; C086661:Fluoroshield; D017438:Bisphenol A-Glycidyl Methacrylate; D004871:Erbium