The aim of this study is to compare the effect of new bioactive dentine substitute (Biodentine) versus glass ionomer cement in very deep carious lesions clinically and radiographically using digital radiography in the terms of postoperative pain and biocompatibility to the pulp.

Roles and responsibilities:

• Omnia Magdy Moustafa (O.M.) Operator, data entry & corresponding author; Assistant lecturer ,
• Mohmed Riad Farid (M.R.) Main supervisor, data monitoring & auditing; Professor, Conservative Dentistry
• Rasha Raffat (R.R.) Co-supervisor, data entry & auditing; Lecturer, Conservative Dentistry Department
• Amir Hafez Ibrahim (A.H.), *Mohamed Refaat El-Bialy (M.E.) (A.H) Lecturer, Conservative Dentistry Department, Faculty of Oral & Dental Medicine Cairo University,(M.E.) Assistant lecturer , Conservative Dentistry Department, Faculty of Oral & Dental Medicine Cairo University outcome assessors and data collection.
• Omar Shalaan (O.S.) Demonstrator, Conservative Dentistry Department, Faculty of Oral & Dental Medicine Cairo University, for baseline data collection, recruitment, sequence generation, allocation concealment, patient retention and taking participants consents.

Interventions:

• Pre-operative clinical assessment :

  1. Thermal testing using Refrigerant spray
  2. percussion test
  3. Palpation and clinical examination
  4. peri-apical radiographs using digital radiograph

• Caries removal procedure:

Local anesthesia will be given to the patient then complete isolation to the tooth using rubber dame the operator O.M. will open the enamel Then in caries removal from the walls carbon-steel rose-head bur. Finally the deeper caries will be removed using spoon excavator

• Intervention : Biodentine™ (Septodont, St. Maur-des-Fossés, France) The material will be applied according to manufacturer instructions
• Comparator: GC Fuji IX GP (GC America Inc, Alsip, IL, USA) The material will be applied according to manufacturer instructions
• Final restoration application:

Filtek™ Z250 Universal Restorative (3M Canada, London, Ontario Canada)

-Adhesive system: Scotchbond Universal Etchant (3M ESPE, St. Paul MN, USA) & Single Bond Universal adhesive (3M ESPE, St. Paul MN, USA).

• The material will be applied according to manufacturer instruction

Inclusion Criteria:

1. Patients male or female older than 18 y in good general health
2. A minimum of 1 deep carious lesion penetrating three-quarters or more into the dentine as identified with the periapical (PA) radiograph; Clinically according to International Caries Detection and Assessment System (ICDAS II) score 4
3. Clinical symptoms of reversible pulpitis
4. Positive pulp response to electric pulp test or thermal stimulation
5. No PA changes viewed on PA radiograph

Exclusion Criteria:

1. Clinical symptoms of irreversible pulpitis requiring endodontic treatment
2. Presence of fistulas or swelling
3. Mobile teeth or tenderness to percussion
4. Anterior teeth with aesthetic concerns
5. Pregnant women, in view of requirements for radiographs
6. Patients younger than 18 y
7. Patients unable to give consent