3D-printed Crowns Versus Prefabricated Stainless-Steel Crowns for Intermediate Restoration of Compromised First Permanent Molars

A total of Forty permanent first mandibular molars in healthy subjects will be selected from the Pediatric Dentistry and Dental Public Health outpatient clinic.

The molars will be randomly assigned equally into two treatment groups group A 3D-printed crowns & group B prefabricated SSCs, removal of caries with a high-speed handpiece then removal of the remaining carious lesion with excavator then glass ionomer restoration will be placed, preparation of SSCs crowns will be done in Group A by reduction of occlusal surface by about 1.5 mm, Proximally, tooth reduction is made through the mesial and distal contact areas, then roundation of line angles. Proper size of crown will be selected. It can also be helpful to measure the dimension of the contralateral tooth. A correctly fitting crown should snap or click at try in. In group B reduction will be performed on the occlusal surface using a flame stone or a wheel stone, to perform occlusal clearance. Reduction will be performed on the mesial, distal, buccal, and lingual surfaces of the tooth Then roundation of the line angles will be performed. Impression for the preparation will be taken using putty and light poly vinyl siloxane material. The preparation will be optically scanned in the lab and the restoration will be digitally designed using computer designing software. The crown will be printed using 3D printer using hybrid resin material. Crown will be checked for proper fit and cemented to the tooth by self-etch adhesive.

Inclusion criteria

• Children included in the study should conform to the following criteria:

• Badly broken-down endodontically treated first permanent molar
• First permanent molar with extensive multi-surface caries.
• First permanent molar with structural developmental defects such as hypoplasia, Molar-Incisor Hypomineralization (MIH), Amelogenesis Imperfecta, and Dentinogenesis Imperfecta

Exclusion criteria

• Children who are uncooperative needing sedation or general anesthesia.
• Children who are physically or mentally disabled or having any medical condition that will complicate the treatment.
• Molars of poor prognosis