Pilot: Marginal Leakage of Composite Restorations on Selectively Excavated Caries Lesions

Objectives: 1. To compare the microleakage of selectively excavated carious lesions with completely excavated carious lesions after restoring with composite resin and a 6th generation bonding agent in the presence or absence of SDF
2. To assess whether there is a correlation between microleakage and Vicker’s microhardness of the dentin surfaces after partial or complete caries excavation.
Methods: Unidentified, extracted, human permanent teeth (N=128) with ICDAS scores 0, 4- 6 were separated into four groups: Group A: ICDAS 0 + no SDF; Group B ICDAS 0 + SDF; Group C ICDAS 4-6 selective caries excavation + no SDF; Group D ICDAS 4-6, Selective Caries Excavation + SDF. Each tooth was embedded in an acrylic block, a class II preparation was completed, Groups B and D received SDF 1 min, after 24 hours, surface conditioned with 37 % phosphoric acid for 15s, bonding agent applied (Scotch Bond, 3M Deutschland) the tooth was restored with composite resin (3MTM FiltekTM Supreme). All groups were thermocycled between 5° and 55°C with a dwell time of 10 seconds, then exposed to 2% methylene blue dye and sectioned occluso-apically. Hardness values are assessed at 6 points on quarter sections (Vickers Hardness Buehler; MicroMet2104). Microleakage analysis was performed using a stereo-optical microscope, Olympus SZX16.
Results: In this pilot study, 20 teeth were classified into four main groups and analysis was completed on them.
Group A, point A: mean and STD :1112.0± 1161.0 ,
Group B, point A: mean and STD : 2324.8± 1265.5 ,
Group C, point A: mean and STD : 365.6± 393.6,
Group D, point A: mean and STD : 674.5± 1195.7.
There was no statistically significant association between group and microleakage when groups A and C were compared to each other (P value > 0.05) as well as when groups B and D were compared to each other (P value > 0.05). To asses differences in microleakage used the paired T test, no statistically signification association was found between group A and B (P value> 0.05)and between group C and D ( P value> 0.05) .
Conclusions: Preliminary results didn’t reach significance, sample sizes will be increased in the full study.
There was a trend for decreased microleakage in groups C and D.
There was moderate strength in the coefficient correlation between microhardness and microleakage values in all the groups.