BioHPP and Lithium Disilicate Onlay Restorations: Clinical Evaluation

Inclusion Criteria: * The teeth planned for onlay restoration (teeth numbered 16, 17, 26, 27, 36, 37, 46, and 47) with destroyed mesial and distal surfaces, but with intact buccal and lingual enamel walls of 2-3 mm thickness. * In the tooth to be treated, the presence of a MOD (mesio-occluso-distal) preparation where the isthmus involves more than half of the buccolingual width of the tooth, or where the distance between the fissure and cusp tip exceeds one-third of the intercuspal distance, including one or more cusps. * Teeth that do not require full crown restoration. * Absence of any other restorations on the adjacent teeth (mesial/distal) or on the opposing teeth corresponding to the tooth planned for onlay restoration. * Since the BioHPP polymer material used in this study is not an esthetic material and does not offer color options, only posterior teeth that do not pose esthetic concerns will be included: maxillary right and left first molars (teeth 16 and 26) and second molars (teeth 17 and 27), as well as mandibular right and left first molars (teeth 46 and 36) and second molars (teeth 47 and 37). Exclusion Criteria: * The relevant tooth being non-vital * Presence of crowns on the adjacent (mesial and distal) or opposing teeth * Absence of proper occlusal contact of the relevant tooth * Patient having periodontitis * Patient age not within the 18-50 year range * Presence of bruxism in the patient