Evaluation And Comparison Of The Accuracy Of Polyvinyl Siloxane And Thermoplastic Resin Interocclusal Registration Materials Using Digital Methods: An In Vivo Study.

Dentistry has witnessed significant advancements due to new technologies, particularly digital scanners and improved materials. These innovations have revolutionized dental practices, providing better options for oral health through enhanced durability and aesthetics.According to the Glossary of Prosthodontics Terms 9th Edition-“An interocclusal record is defined as a registration of the positional relationship of the opposing teeth or arches; a record of the positional relationship of the teeth or jaws to each other.â€Interocclusal registration materials have the main purpose of accurately replicating cuspal morphology, withstanding compressive forces, and maintaining dimensional stability during transport. These materials are used to record the occlusal relationship between natural and artificial teeth, particularly for prosthesis planning. They should offer minimal resistance before setting, be rigid or resilient post-setting with minimal dimensional changes, and be easy to manipulate without adverse effects on tissues. It’s crucial for the material to accurately record the incisal and occlusal surfaces of teeth and be verifiable for precise bite registration. Examples of interocclusal materials include Addition silicone impression material, Zinc oxide eugenol paste, Corrected wax, Metalized wax, Elastomers, Impression plaster, Acrylic resin, and Pressure-sensitive films.The selection of the right interocclusal recording material is crucial for reliable prosthodontic treatment. New materials have led to significant advancements in achieving accurate results. Intraoral scanners have improved precision compared to conventional methods. Polyvinyl siloxane is considered the optimal material, and its accuracy will be compared to thermoplastic resin using intraoral scanners.PRIMARY OBJECTIVES 1)To evaluate the accuracy of Polyvinyl Siloxane as an interocclusal registration material obtained from an extraoral digital scanner. 2)To evaluate the accuracy of Thermoplastic Resin as an interocclusal registration material obtained from an extraoral digital scanner. 3)To compare the accuracy of Polyvinyl Siloxane and Thermoplastic Resin as an interocclusal registration material obtained from an extraoral digital scanner with the intraoral scanner. Method of measurement:In the study, 14 candidates will be carefully selected based on specific criteria. Tooth preparation for crown prosthesis will be carried out on endodontically treated teeth without distal teeth present. Intraoral scanning will be performed following the manufacturer’s instructions, including air-drying the teeth before scanning. Both upper and lower arches, along with their occlusal surfaces and interocclusal relationship, will be thoroughly scanned. The subjects will be instructed to position their mandible in the maximal intercuspal position, and the facial surfaces of the maxillary and mandibular arches will be scanned without any pauses. The captured images will be exported in STL format. Additionally, two sets of impressions will be taken using Addition silicone impression material, and intermaxillary relationships will be recorded with either Polyvinyl Siloxane or Thermoplastic Resin materials.