In Vitro and in vivo evaluation of esthetic restorative materials used in restorations of cervical caries

-170- SUMMARY Generally, in cervical restorations, the coronal margins are usually in enamel, while the cervical margins are in dentin and cementum and these cavities are called Class V cavities. For restoring cervical cavities, different types of adhesive systems and esthetic restorative materials can be used and a restorative system that bonds equally well to enamel and dentin is desirable. The aim of this study was to evaluate in vivo and in vitro performance of different types of adhesive sytems and light cured tooth colored materials such as resin modified glass ionomer restorative material, polyacid modified resin composite, microfilled composite resin and hybrit type composite resin. In vitro evaluation were based on the measurement of adhesive interface thickness and microleakage. In order to determine adhesive interface thickness of the specimens, Class V cavities (mesiodistal width of 3 mm, occlusogingival length of 2 mm and a depth of 2 mm) were prepared on the buccal surface of SO extracted noncarious premolar teeth at the cementoenamel junction. The occlusal margins of the preparation were in enamel and the gingival margins were in dentin and cementum. The prepared teeth randomly divided into 5 groups of 10. Tested groups are as follows:-171- Group 1: One-step smear layer modifying system (Compoglass SCA prime/adhesive system) + polyacid modified resin composite (Compoglass) Group 2: Three-step smear layer removing system (Scotchbond Multi Purpose Plus Adhesive System) + microfilled composite resin (Silux Plus) Group 3: Three-step smear layer removing system (Scotchbond Multi Purpose Plus Adhesive System) + hybrit type composite resin (Z 100) Group 4: Two-step smear layer removing system filled with fluoride (Syntac Single- Component Adhesive System) + hybrit type composite resin with fluoride (Tetric) Group 5: Three-step smear layer removing system filled with fluoride (Optibond) + hybrit type composite resin (XRV Herculite) During the restoration procedure, all materials were placed into two increments. The occlusal increment was placed first. Each increment was cured with visible light application for 40 seconds. The restorations were finished with a 12- fluted high-speed carbide bur and polished with a series of Sof-Lex disks from coarse to fine. After completing the restorations, the teeth were stored in 37°C water bath for 24 hours, before sectioning the the teeth buccolingually utilising a slow speed saw. Adhesive interface thickness was measured under scanning electron microscope with the aid of 10 different site measurements. As a result, it was noted that, film thickness of adhesive interface was not homogenous for all tested systems. Comparing with the other systems, one-step-172- smear layer modifying system showed the highest adhesive interface thicknesses (p<0.05). Other tested systems revealed similar adhesive interface thicknesses (p>0.05). In order to assess the microleakage of different types of tooth colored restorative materials, Class V cavities (mesiodistal width of 3 mm, occlusogingival length of 2 mm and a depth of 2 mm) were prepared on the buccal surface of 240 extracted noncarious premolar teeth at the cementoenamel junction. The occlusal margins of the preparation were in enamel and the gingival margins were in dentin and cementum. The occlusal enamel margins of the 120 cavities were bevelled (45°, 0.5 mm) with a fine diamond point. Then light cured resin modified glass ionomer lining material were applied to the 60 bevelled and 60 non-bevelled cavities before the restorative materials were placed. The cavities were restored with six different restorative materails with and without bevelling and with and without lining. For each tested groups 10 cavities were restored as follows: Group 1 A: bevelled cavity, with lining + Fuji II LC Group IB: bevelled cavity, without lining + Fuji II LC Group 1C: non-bevelled cavity, with lining + Fuji II LC Group ID: non-bevelled cavity, without lining + Fuji II LC-173- Group 2A: bevelled cavity, with lining + Compoglass Group 2B: bevelled cavity, without lining + Compoglass Group 2C: non-bevelled cavity, with lining + Compoglass Group 2D: non-bevelled cavity, without lining + Compoglass Group 3 A: bevelled cavity, with lining + Silux Plus Group 3B: bevelled cavity, without lining + Silux Plus Group 3C: non-bevelled cavity, with lining + Silux Plus Group 3D: non-bevelled cavity, without lining + Silux Plus Group 4 A: bevelled cavity, with lining + Z 100 Group 4B: bevelled cavity, without lining + Z 100 Group 4C: non-bevelled cavity, with lining + Z 100 Group 4D: non-bevelled cavity, without lining + Z 100 Group 5 A: bevelled cavity, with lining + Tetric Group 5B: bevelled cavity, without lining + Tetric Group 5C: non-bevelled cavity, with lining + Tetric Group 5D: non-bevelled cavity, without lining + Tetric Group 6A: bevelled cavity, with lining + XRV Herculite Group 6B: bevelled cavity, without lining + XRV Herculite Group 6C: non-bevelled cavity, with lining + XRV Herculite Group 6D: non-bevelled cavity, without lining +XRV Herculite During the restoration, all materials were placed into two increments. The occlusal increment was placed first. Each increment was cured for 40 seconds.?174- The restorations were finished with a 12-fluted high-speed carbide bur and polished with a series of Sof-Lex disks from coarse to fine. After completing the restorations, the teeth were stored in 37°C water bath for 24 hours and then all restored teeth were coated with nail polish with 1 mm circumference around the restorations free of polish. Before sectioning the the teeth buccolingually utilising a slow speed saw, the teeth were immersed in 2 % methylene blue solution for 24 hours for microleakage evaluation. Dye penetration was scored both occlusal and gingival margins. Considering the cavity design, for all tested materials bevelling and lining did not affect the final microleakage values. However, comparing tested materials, there was a significant differences between all the tested materials (p<0.05). Resin modified glass ionomer restorative material, Fuji II LC, showed highest microleakage scores. However, microleakage of occlusal and gingival margins did not exhibit statistically significant differences (p>0.01). All composite resin materials showed lowest microleakage degree without depending the types of the composite resins. However, occlusal margins revealed less leakage than the gingival margins. In vivo evaluation was based on the restoration of active caries lesion on the buccal surface of the teeth with different types of restorative materials such as?175- resin modified glass ionomer restorative material, polyacid modified resin composite, microfilled composite resin and hybrit type composite resin. For each tested group 30, total 180 cervical lesion were restored by a single operator in 50 patients (23 female, 27 male and aged between 35-45). During removing the caries, cavity margins did not bevelled and after cavity preparations, cavities did not lined. All restorations were evaluated by two experienced examiners at baseline, 6 months, 1 year, 2 years and 3 years after placement. Examiners were used American Dental Association Guidelines for dentin and enamel bonding materials by means of retention, marginal integrity, marginal discoloration, color match, anatomic form, surface texture, surface staining, seconder caries, gingival response and postoperatif sensitivity. Based on the obtained data all restorations satisfied all examined criteria. However, restorative material with compatible adhesive system performed better than restorative material without adhesive system such as Fuji II LC. After 3 years clinical wear of the restorations, 10 impressions for each tested restorative materials were taken and replica models were made with using epoxy resin. Utilising epoxy replica models, marginal integrity and surface texture of the materials were evaluated under scanning electron microscope. It was shown that marginal integrity and surface texture observations of replica models were well correlated with clinical findings of the restorations.