Objectives: To characterize the adhesion of two pit-and-fissure sealants to unprepared enamel using 35% phosphoric acid vs. a self-etching bonding system (Adper Prompt L-Pop, PLP, 3M ESPE). Methods: Proximal enamel surfaces of extracted molars were treated with one of the four conditioners shown in Table. One of two sealants (Clinpro, 3M ESPE; Delton, Dentsply) was applied in a thin layer (0.50 to 0.75 mm), followed by a composite buildup (Z250, 3M ESPE) to provide a gripping surface. Specimens were cut in X and Y directions in sticks with section of 0.7±0.1mm2 and tested in an Instron at 1mm/min at 24h. µTBS data in MPa were analyzed with one- and two-way ANOVA/Tukey’s (superscript letters, p<0.05). Results:
|
Enamel Conditioning |
Pooled Mean |
Sealant |
Mean±SE |
N |
|
Group A = 35% H3PO4 for 15 sec, rinse, dry |
15.57ab
|
Clinpro |
15.69B±1.240 |
35 |
|
Delton |
15.45B±1.160 |
40 |
||
|
Group B = PLP, 1 coat cured prior to application of sealant |
9.49c
|
Clinpro |
9.77C±1.190 |
38 |
|
Delton |
9.22C±1.240 |
35 |
||
|
Group C = PLP, 2 coats cured prior to application of sealant |
19.19a |
Clinpro |
22.78A±0.998 |
54 |
|
Delton |
15.16B±1.059 |
48 |
||
|
Group D = PLP, 1 coat co-cured with the sealant |
17.32ab |
Clinpro |
16.60B±1.037 |
50 |
|
Delton |
18.03AB±1.027 |
51 |
There was a significant difference between means for “sealant” at p<0.028 (Clinpro>Delton). For “surface etchant/conditioner”, Groups A, C, and D resulted in similar bond strengths at p<0.05, while the means for Group B were statistically lower. The combinations Group C/Clinpro and Group D/Delton ranked in the highest statistical subset. Conclusion: PLP applied in 2 coats and cured prior to sealant application is as effective for sealant bonding as either PLP applied in 1 coat and co-cured with the sealant or phosphoric acid etching. The application of PLP in 1 coat cured prior to sealant application is not recommended. This project was supported by 3M ESPE.