Pneumatization of the maxillary sinus may lead to insufficient bone volume for dental implant placement in the edentulous posterior maxilla. Sinus floor elevation (SFE) surgery with the lateral window technique is a safe and predictable surgical intervention to restore bone height in the maxillary premolar and molar areas. According to the literature, several bone graft materials may be successfully applied for SFE surgery. There is a lack of evidence regarding the application of biphasic calcium sulfate (BCS) for SFE. The healing period following staged SFE is 2-9 months. The aim of this study is: * to evaluate the success of SFE surgery using BCS as graft material, * to compare the microarchitecture of the augmented bone depending on the healing period, * to evaluate the success of dental implants placed in the augmented bone and that of the prostheses delivered on the dental implants.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
40
Patients rinse with 0.2% chlorhexidine solution for one minute before surgery. Under local anesthesia, a mucoperiosteal flap is raised from a midcrestal incision and two relieving incisions. Lateral window osteotomies are carried out using diamond burs. The Schneiderian membrane is carefully elevated and the synthetic bone graft material (Bond Apatite, Augma Biomaterials, Cesarea, Israel) (2-3 cm3) is packed in the defect with light force. The buccal flap is then mobilized to allow tension-free primary closure. The margins are stabilized with single interrupted sutures. Antibiotics (1 g amoxicillin-clavulanate twice a day for 5 days, or in case of side effects or known allergy to penicillin, 300 mg clindamycin 4 times a day for 4 days), anti-inflammatory drugs (50 mg diclofenac 3 times a day for 3 days), and chlorhexidine mouthwash (twice a day for 21 days from the first day after surgery) are prescribed. Suture removal takes place after 10 days.
A CBCT scan is performed before SFE surgery to evaluate the anatomy and pathologies of the maxillary sinus.
A CBCT scan is performed following the 3- or 6-month-long healing period after SFE to evaluate the anatomy and healing of the augmented bone and the maxillary sinus.
At the time of dental implant placement, the first step of the implant bed preparation is performed using a trephine drill to harvest a bone core biopsy sample from the augmented bone. The biopsy sample is harvested from the implant bed, this way the patient is spared of excess surgical burden as this bone would be removed even if no biopsy sample was harvested during dental implant placement. The bone core biopsy samples are subjected to histomorphometric and microCT analysis.
Following the 3- or 6-month-long healing period following SFE, dental implants are placed non-submerged in the augmented bone under local anesthesia.
3 months after dental implant placement, fixed dental prostheses are delivered on the dental implants.
A synthetic bone graft material (Bond Apatite, Augma Biomaterials, Cesarea, Israel) is used during SFE.
Semmelweis University Department of Public Dental Health
Budapest, Budapest, Hungary
RECRUITINGSuccess of the SFE
The SFE surgery is successful if no inflammatory complications occur in the 3- or 6-month-long healing period and the bone volume is sufficient for dental implant placement.
Time frame: 3 or 6 months
Success of the dental implants
According to The International Congress of Oral Implantologists (ICOI) Pisa Consensus Conference. Success (optimum health) 1. No pain or tenderness upon function 2. 0 mobility 3. less than 2 mm radiographic bone loss from initial surgery 4. No exudates in the patient's history II. Satisfactory survival 1. No pain on function 2. 0 mobility 3. 2-4 mm radiographic bone loss 4. No exudates in the patient's history III. Compromised survival 1. May have sensitivity on function 2. No mobility 3. Radiographic bone loss of more than 4 mm (less than1/2 of the length of the implant body) 4. Probing depth more than 7 mm 5. May have exudates in the patient's history IV. Failure (clinical or absolute failure) Any of the following: 1. Pain on function 2. Mobility 3. Radiographic bone loss of more than 1/2 length of the implant 4. Uncontrolled exudate 5. Implant no longer in mouth
Time frame: 5 years
Success of the implant borne prostheses
Prostheses with four or fewer complications (screw loosening, decementation, chipping) that could be treated chairside.
Time frame: 5 years
Hisomorphometry: Percent of residual bone graft particles
The percentage of residual bone graft particle-area measured on the representative sections prepared from the bone core biopsy samples. Unit: percent (%)
Time frame: 3-6 months
Hisomorphometry: Percent of newly formed bone
The percentage of newly formed bone-area measured on the representative sections prepared from the bone core biopsy samples. Unit: percent (%)
Time frame: 3-6 months
Hisomorphometry: Percent of bone marrow
The percentage of bone marrow-area measured on the representative sections prepared from the bone core biopsy samples. Unit: percent (%)
Time frame: 3-6 months
Value of the percent bone volume (BV/TV) calculated from the microCT reconstructions of the bone core biopsy samples.
Relative volume of calcified tissue in the selected volume. Unit: none
Time frame: 3-6 months
Value of the bone surface to volume ratio (BS/TV), calculated from the microCT reconstructions of the bone core biopsy samples.
Ratio of the segmented bone surface to the total volume in the region of interest. Unit: 1/mm
Time frame: 3-6 months
Value of the trabecular thickness (Tb.Th.), calculated from the microCT reconstructions of the bone core biopsy samples.
Mean thickness of the trabeculae, assessed using direct 3D methods. Unit: mm
Time frame: 3-6 months
Value of the trabecular separation (Tb.Sp.), calculated from the microCT reconstructions of the bone core biopsy samples.
Mean distance between the trabeculae, assessed using direct 3D methods. Unit: mm
Time frame: 3-6 months
Value of the trabecular bone pattern factor (Tb.Pf), calculated from the microCT reconstructions of the bone core biopsy samples.
Indicator of the relation between convex and concave elements in the trabecular bone structure. Tb.Pf \<0 when the trabecular bone is honeycomb-like and increases as the trabecular bone acquires a rod-like structure. Unit: none
Time frame: 3-6 months
Value of the structure model index (SMI), calculated from the microCT reconstructions of the bone core biopsy samples.
The estimator of the plate- versus rod-like characteristic of the trabecular bone structure, 0 for perfect plates, 3 for perfect rods, and 4 for perfect spheres. Unit: none
Time frame: 3-6 months
Value of the Total porosity (Po(tot)), calculated from the microCT reconstructions of the bone core biopsy samples.
Percent porosity is the volume of pores as a percent of the total volume of interest (VOI). Unit: percent (%)
Time frame: 3-6 months
Value of the Connectivity (Conn.), calculated from the microCT reconstructions of the bone core biopsy samples.
One useful and fast algorithm for calculating the Euler connectivity in 3D is the "Conneulor". It measures what might be called "redundant connectivity", the degree to which parts of the object are multiply connected. It is a measure of how many connections in a structure can be severed before the structure falls into two separate pieces. Unit: none.
Time frame: 3-6 months
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