Evaluation of the Accuracy of Root Guided Immediate Implant Placement at Maxillary- Molar Region

Purpose: This study aimed to evaluate the accuracy of the root guide technique in comparison to the surgical guide technique for immediate implant placement in the maxillary- molar region radiographically and clinically.

Materials \& Methods:Twenty patients with non restorable maxillary molar will be included in this study. The patients will be divided randomly (10 patients each group). Group I,immediate implant placement will be done using root guide technique.Group II,immediate implant placement will be done using surgical guide technique.The patients will be received, clinically and radiologically examined, and managed at the Oral and Maxillofacial surgery Department,Faculty of Dentistry, Tanta University.The patients will be evaluated clinically to evaluate healing and radio graphically using cone beam CT (CBCT) scan to identify bone density post operative and after 6 months.

Preoperative evaluation: The patients will be evaluated clinically and radiographically using Cone beam CT(CBCT) scan , before implant placement for assessment of the anatomy of inter-radicular septum and tooth roots ,periapical pathology , bone density and approximation of vital structures , then we will make virtual planning to future implant position.

• fabrication of surgical guide stent( tooth born ): will be done for Group II, Conventional impression will be taken with irreversible hydrocolloid to make a diagnostic cast.
• The cast will be scanned with a laboratory scanner.
• -The scanned data of the cast will exported as a standard tessellation language (STL) file, while the CBCT image will saved as Digital Imaging and Communications in Medicine (DICOM) data 26 .
• -Design of the surgical guide proceeded with superimposition of the STL file to the CBCT data through a software [Blue Sky software].⃰
• -Completion of virtual implant treatment planning with proper adjustment, the adequate position of the implant will planned with the creation of open sleeve.
• -Selection and fabrication of surgical guide based on the computed tomography model and print it by Creality LD006 ⃰⃰

Surgical procedure:

Stage 1:

Group I:

All patients will undergo the surgery under local anesthesia. We will do coronctomy to the level of free gingiva and separation of the roots with surgical fissure bur ,drilling the implant site according to manufacture's proptocl will be done with roots intact in their sockets within the inter-radicular bone. Clinically visible roots will be extracted by using periotomes .Following extraction, the socket will be debrided to remove any reminants and the socket and osteotomy will be irrigated by sterile normal saline . The implant will be inserted into the site following manufacture's protocol.

GroupII All patients will undergo the surgery under local anesthesia. Surgical separation of the roots will be done by surgical fissure bur , separated roots will be extracted by periotomes , the socket will be debrided to remove any reminants and irrigated by sterile normal saline. Following extraction, drilling the implant site will be done through the surgical guide (tooth supported surgical guide) according to manufacturer's protocol, implant will be inserted into the site following manufactures protocol.

• After insertion of the implant in both groups: the primary stability will be measured by Osstell device (resonance frequency analyzer, (RFA) is a device that uses resonance frequency analysis to measure implant stability quotient (ISQ)) , then we will fill the gap between the implant and walls of the socket by bone graft graft(xenogeneic bone graft) and PRF (platelets- rich fibrin) around the implant into the socket , finally custom mad haling abutment will b made.

Postoperative evaluation: The patients will be evaluated clinically regarding healing, presence of inflammation,and swelling each week at the first month then after 3 months and 6 months and assess pain, by Visual Analog Scale weekly during the first month (at days 1,7, and14). . Implant stability will be assessed at the time of implant insertion and 6 months after the operation.

Radiographically,During the follow-up period a CBCT will be taken immediately postoperative and 6 months after the operation.

Immediate CBCT was to compare the actual position of the implant with the preoperative virtual planning of the implant position by superimposition of preoperative and postoperative CBCT. Three deviation parameters between each planned and placed implant were measured :

• Horizontal deviation at coronal side of the implant.
• Horizontal deviation at apex of the implant
• Angular deviation. All measurements were performed using Mimics Innovation Suite 19tm software.

Stage II( crest module uncoverage and healing abutment installation).:

After 6 months of consolidation and osseointegration period, CBCT was done to assess the oseteointegration . A surgical re-entry procedure performed to allow access to the crest module of the fixture.

Prior to the start of surgery, the patient rinsed his mouth with betadine for 1 min. The oral cavity was scrubbed with betadine (povidine iodine 2.5%) antiseptic solution.

Under local anesthesia ,custom made healing abutment was removed to exposure the implant . Smart peg was installed at the fixture level to assess secondary implant stability before loading.A healing abutment selected according to the soft tissue thickness installed until gingival collar becomes adequate around the implant.

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