Effect of an Additional Hydrophobic Adhesive Layer Application on the Class V Composite Restorations

Effect of an Additional Hydrophobic Adhesive Layer Application on the Clinical Performance of Class V Composite Restorations: an 18-month Randomized Clinical Trial

In restorative dentistry, to enhance bond strength between dentin and simplified adhesive systems, new materials or applications are constantly being developed all the time. In order to create a better hybrid layer quality, modifications are made to the chemical contents and application methods of the adhesives. For inhibition or slow down of collagen or resin matrix degradation at the adhesive interface, procedures like using protease enzyme inhibitors or additional hydrophobic layer applications are tested by in vitro and in vivo studies.

The main goal of this double-blind randomized clinical trial is to evaluate the 18-month clinical performances of two different one-step dentin adhesives that were applied alone or with an additional hydrophobic adhesive layer to non-carious cervical lesions.

The hypotheses are that (1) Additional Hydrophobic Adhesive layer application can provide better clinical performance in class V restorations and, (2) the HEMA content will cause statistically different clinical performances.

In this study, Clearfil S3 Bond Plus (one-step self-etch adhesive), G-Premio Bond (Universal adhesive), Heliobond (additional hydrophobic adhesive), and Clearfil Majesty ES-2 (nano-hybrid composite) materials will be used. After performing selective etching with Scotchbond Universal Etchant, four different adhesive procedures will be applied according to manufacturers' instructions to the non-carious cervical lesions selected by the randomized method. In the first group Clearfil S3 Bond Plus, in the second group Clearfil S3 Bond Plus and additional hydrophobic adhesive layer (Heliobond), in the third group G-Premio Bond, in the fourth group, G-Premio Bond and additional hydrophobic adhesive layer (Heliobond) will be applied to the NCCL lesions. Restorations will be accomplished by using Clearfil Majesty ES-2 composite material. Restorations will be evaluated according to FDI criteria. Esthetic properties will be evaluated with surface luster, marginal staining, color match and translucency, esthetic anatomical form parameters. Functional properties will be evaluated with fracture and retention, and marginal adaptation parameters. Biological properties will be evaluated with post-operative sensitivity, periodontal response, and secondary caries parameters. Scores 1, 2, and 3 represent clinically acceptable restorations, and scores 4 and 5 represent clinically unacceptable restorations.

Inclusion Criteria:

• 18 and over 18 years old
• Having acceptable oral hygiene
• Good general health
• Having at least 20 teeth in occlusion
• Presence of at least 4 non-carious cervical lesions in the mouth that require treatment
• Lesions without caries
• Patient's consent to come to control appointments
• Vital and non-mobility of the tooth with the lesion
• During occlusion, the tooth with the lesion is in contact with the antagonist tooth.

Exclusion Criteria:

• Under 18 years old
• Having poor oral hygiene
• Poor general health condition
• Pregnancy or breastfeeding status
• Orthodontic application in the last 3 months
• The tooth with the lesion has pulpitis, mobility or it is non-vital
• Presence of advanced bruxism
• The tooth with the lesion is a prosthetic abutment
• Presence of advanced periodontitis or periodontal surgery in the last 3 months