Evaluation of Low-shrinkage Giomer Versus Resin-Modified Glass Ionomer in Cervical Caries Lesions: A Clinical Trial

Management of cervical lesions presents serious problems with any restorative material. The two most common reasons for restoration failure are secondary caries at the tooth-restoration interface and loss of retention. Class V lesions often exhibit a low retentive cavity configuration (C-factor); which is responsible for marginal gaps around the restorations. Cervical margins -lying in either dentin or cementum- show unfavorable bonding performance, besides being usually subgingival where moisture control is difficult. The subgingival margin is not clinically desirable due to difficulty in cleaning and increased biofilm accumulation. Therefore, the selection of the restorative material can be challenging. Resin composites are known for their high mechanical properties, excellent esthetic properties, and ease of clinical application. However, when compared with glass ionomers, resin composite has no cariostatic effect on tooth structure. In addition, microleakage caused by polymerization shrinkage of resin composite leads to plaque accumulation and secondary caries. On the other hand, resin-modified glass ionomer has many advantages, yet still it has lower weakness and esthetic properties compared to resin composite. Based on current literature, there is limited evidence comparing clinical performance of low-shrinkage giomer resin composite to resin-modified glass ionomer in the treatment of cervical caries lesions. This study is conducted to evaluate the clinical performance of low-shrinkage giomer resin composite versus resin-modified glass ionomer in treatment of cervical caries lesions, using both Modified USPHS and Revised FDI criteria. This study will be designed to test the null hypothesis that the low-shrinkage giomer resin composite will have the same clinical performance as resin-modified glass ionomer in cervical restorations, using both Modified USPHS and Revised FDI criteria.