Influence of demineralized dentin on marginal seal using primerless wet bonding technique: in-vivo study

Abstract

The purpose of this study was to compare microleakage distance between Class V restorations and tooth interface when using either 4-META-MMA/TBB or MMA/TBB resin adhesives by using 1 % ferric chloride in 1% citric acid (1-1) for conditioning periods of 10s (1-1-10s) 30s (1-1-30s) and 60s (1-1-60s) for in-vivo study. Material and methods: A total of 60 Class V box cavities were divided into 6 groups of 10 specimens (n= 10) on the caries-free, vital, and hopeless periodontally-compromised teeth, scheduled for extraction. A Class V cavity (3mm × 3mm × 1.5mm) was prepared on the buccal or lingual surface located at the cemento-enamel junction of each tooth providing margins in enamel and cementum/dentin. All cavities were conditioned with 1-1 aqueous conditioner for 10 s, 30s or 60s each group, rinsed off with water for 10 s, blot-dried for 10s and bonded with different resin adhesives (4-META/MMA-TBB or MMA-TBB) before coupled with light-cured resin composite. Restored teeth continued under function in oral cavity for 7 days before extraction. After extraction, all specimens were coated with nail varnish, except for restorations and 1 mm away from occlusal and cervical margins, then immersed in 0.5 % basic fuchsin dye solution for 24 h. All specimens were vertically sectioned. The margin and distance of dye penetration was investigated by a stereomicroscope. Results: There is no leakage at the tooth-resin interface at enamel and cementum/dentin margins either using 4META-MMA/TBB or MMA/TBB resin for all etching periods. Only 1 specimen of 60s etching and bonding with MMA/TBB resin has leakage distance at cementum/dentin margin of 0.13 mm. Conclusion: Impermeable hybridized interfaces were formed in all groups with 4META- MMA/TBB or MMA/TBB resin using (1-1) to condition tooth surface for 10-60 seconds. No leakage along tooth-adhesive interface was found in clinically. This suggests the ability of leakage prevention which help prevent tooth sensitivity, caries under the restorations and/or infection in the pulpal cavity predicting the long-term success of restored teeth.