Accuracy of Selective Laser Sinteredcomputer Guided Stents Versus Digital Light Processing Stents

the principle investigator will randomize and equally distribute the Eligible patients between the selective laser sintering group (intervention group) and digital light processing group (control group).

• Diagnostic phase : for initial diagnosis, principle investigator will make primary impression , bite registration, face bow record and periapical x-ray for each eligible patients. The tooth to be extracted will be removed from the cast and replaced with an artificial tooth. For construction of radio graphic stent, a clear thermoplastic sheet will be pressed on the modified cast using a vacuum forming machine . A hole is done in the center of the artificial tooth packed with heated gutta percha (radiopaque material) for easy visualization on the cone beam during virtual implant placing. A dual scan protocol with cone beam CT will be made. The first scan is for the patient wearing the scan appliance while the second will be for the cast with the scan appliance.
• Planning phase : placing of the virtual implant and designing of the surgical stent will be done by virtual planning software .
• Construction of the surgical guide: principle investigator will send the Standard Language transformation (STL) file of the designed guide to a rapid prototyping center. Selective laser sintering and digital light procesing will be used for intervention and control group respectively. principle investigator will check for adaption of the guide on the cast and cement the metallic sleeve to prevent rotation during surgery.
• Surgical phase : principle investigator will prescribe a prophylactic antibiotic to the patient three days prior the surgery. Atraumatic extraction will be carried by periotomes and lancet. The integrity of the socket will be examined well by probe. The guide is stabilized in its place then drilling and implant placement will be done. Healing abutment is screwed in place to allow proper healing of the soft tissue. Patient will be instructed to avoid hard foods and follow restrict oral hygiene measures. Patient will be recalled after one week for postoperative inspection and assessment. A cone beam CT will be taken for deviation assessment.

Inclusion criteria

• Patient age should be more than 18 years old
• Hopeless tooth in esthetic zone due to caries, endodontical problem or trauma with both neighboring teeth present.
• Good oral hygiene
• No periapical lesions (acute accesses or chronic fistula)
• Adequate bone (5 mm) below the tooth to allow primary implant stability
• Sufficient Medio-distal bone about 1.5 from each side
• sufficient labial bone
• sufficient band of keratinized mucosa

Exclusion criteria

• heavy smoking
• any systemic condition that is considered absolute contraindication for implant placement
• pregnancy
• in adequate inter-arch space
• parafunctional habits as bruxism